Smart antenna connect mechanism to achieve signal integrity without affecting voltage standing wave ratio

Information

  • Patent Grant
  • 6317085
  • Patent Number
    6,317,085
  • Date Filed
    Tuesday, March 2, 1999
    25 years ago
  • Date Issued
    Tuesday, November 13, 2001
    22 years ago
Abstract
Systems and methods are described for detachable antennas. A wireless communications device includes: a cam body defining a rotation axis, the cam body including a retaining zone having a snap-fit receptacle; a signal pin including a first signal pin end and a second signal pin end; an antenna conductively coupled to the first signal pin end; a signal clip with a protrusion, a contact pad with a recess, and a key pin that extends from the signal pin, the key pin having a first key pin end and a second key pin end, and being snap-fit into the snap-fit receptacle. The systems and methods provide advantages in that the detachable antenna is easily replaced without tools.
Description




BACKGROUND OF THE INVENTION




1. Field of the Invention




The invention relates generally to the field of radio frequency (RF) communications. More particularly, the invention relates to RF antennas that can be detached from a wireless communication device, especially a personal data assistant.




2. Discussion of the Related Art




Prior art personal data assistants, sometimes called PDAs, are known to those skilled in the art. A transfer of data with a personal data assistant is typically enabled by physically connecting the personal data assistant to another electronic device (e.g., a personal computer) with a serial cable. The transfer of data can then take place between the personal data assistant and the other electronic device via electrical signals that are carried by the serial cable.




More recently, the transfer of data with the personal data assistant has become possible by optically connecting the personal data assistant to the other electronic device (e.g., a second personal data assistant). The transfer of data can then take place between the personal data assistant and the other electronic device via optical signals (e.g., infrared band) that are propagated through free space.




A problem with this personal data assistant data transfer technology has been that, for the transfer of data to take place, the personal data assistant must either be physically connected to the other electronic device or within a short line of sight distance to the other electronic device. Therefore, what is needed is solution that permits a transfer of data between the personal data assistant and another electronic device even when a physical or optical connection is not possible.




Meanwhile, it has been known in the field of communications to provide a radio frequency (RF) communications device with a compact antenna. Prior art RF communication devices, such as cellular phones, are known to those skilled in the art. Cellular phones are usually provided with a compact antenna. To minimize the overall size of such a communications device, these compact antennas are often provided in a deployable/retractable form so that the compact antenna can be at least partially withdrawn into the balance of the communications device during those times when data transfer it not needed. Cellular phones are typically provided with a longitudinally extending compact antenna.




A problem with this compact antenna technology has been that compact antennas are susceptible to mechanical failure. Repeated deployment and retraction of the compact antenna can lead to weakening of the mechanism and, eventually, breakage. Further, compact antennas are inherently fragile because of their small size and weight.




Despite their susceptibility to wear and damage, most compact antennas are not replaceable. Even in the case of compact antennas that are replaceable, the replacement operation is not easy and requires the use of tools to disassemble the communications device, replace the antenna subassembly, and then reassemble the communications device. Therefore, what is also needed is a solution that provides permits a compact antenna to be quickly and easily replaced by the end user of the communications device, without any tools.




Heretofore, the two requirements of wireless, beyond line of sight data transfer with a personal data assistant and easy replacement of a deployable/retractable compact antenna referred to above have not been fully met. What is needed is a solution that simultaneously addresses both of these requirements.




SUMMARY OF THE INVENTION




A primary object of the invention is to provide a detachable antenna. Another primary object of the invention is to provide a wireless communications device, for example, a personal data assistant, with a detachable antenna. Another primary object of the invention is to provide a method of deploying and/or retracting a detachable antenna.




In accordance with these objects, there is a particular need for a detachable antenna that can be reversibly snap-fit into a communications device. Thus, it is rendered possible to simultaneously satisfy the above-discussed requirements of beyond line of sight data transfer with a personal data assistant and easy replacement of a deployable/retractable compact antenna, which, in the case of the prior art, are not simultaneously satisfied.




A first aspect of the invention is implemented in an embodiment that is based on a detachable antenna, comprising: a cam body defining a rotation axis, said cam body including a retaining zone having a snap-fit receptacle; a signal pin including a first signal pin end and a second signal pin end; an antenna conductively coupled to said first signal pin end; and a key pin that extends from said signal pin, said key pin having a first key pin end and a second key pin end, and being snap-fit into said snap-fit receptacle. A second aspect of the invention is implemented in an embodiment that is based on a method of attaching a detachable antenna to a wireless communications device, said method, comprising: providing a detachable antenna that includes a signal pin and a key pin connected to said signal pin; inserting said key pin and at least part of said signal pin into a cam body that composes said wireless communications device so as to define a first detachable antenna position; and deflecting said detachable antenna from said first position to a second position. A third aspect of the invention is embodied in a method of detaching a detachable antenna from a wireless communications device, said method comprising: providing said detachable antenna with a signal pin and a key pin connected to said signal pin; deflecting said detachable antenna from a first position to a second position; and removing said key pin and at least part of said signal pin from a cam body that composes said wireless communications device.




These, and other, objects and aspects of the invention will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following description, while indicating preferred embodiments of the invention and numerous specific details thereof, is given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the invention without departing from the spirit thereof, and the invention includes all such modifications.











BRIEF DESCRIPTION OF THE DRAWINGS




A clear conception of the advantages and features constituting the invention, and of the components and operation of model systems provided with the invention, will become more readily apparent by referring to the exemplary, and therefore nonlimiting, embodiments illustrated in the drawings accompanying and forming a part of this specification, wherein like reference characters (if they occur in more than one view) designate the same parts. It should be noted that the features illustrated in the drawings are not necessarily drawn to scale.





FIG. 1

illustrates a perspective view of a wireless communications device with a detachable antenna positioned at approximately zero degrees, representing an embodiment of the invention.





FIG. 2

illustrates a perspective view of the wireless communications device shown in

FIG. 1

with the detachable antenna positioned at approximately 90 degrees, representing an embodiment of the invention.





FIG. 3

illustrates a perspective view of the wireless communications device depicted in

FIGS. 1-2

with the detachable antenna positioned at approximately 135 degrees, representing an embodiment of the invention.





FIG. 4

illustrates a perspective view of the wireless communications device shown in

FIGS. 1-3

with the detachable antenna positioned at approximately 180 degrees, representing an embodiment of the invention.





FIG. 5

illustrates a perspective view of the outside of a front housing of the wireless communications device together with a cam body, representing an embodiment of the invention.





FIG. 6

illustrates a perspective view of the detachable antenna, representing an embodiment of the invention.





FIG. 7

illustrates a perspective view of the inside of the front housing of the wireless communications device, representing an embodiment of the invention.





FIG. 8

illustrates a perspective view of the front housing shown in

FIG. 7

together with the cam body, representing an embodiment of the invention.





FIG. 9

illustrates a perspective view of the front housing shown in

FIGS. 7-8

together with the cam body and a detent clip, representing an embodiment of the invention.





FIG. 10

illustrates a perspective view of the front housing depicted in

FIGS. 7-9

together with the cam body, the detent clip, and a signal clip, representing an embodiment of the invention.





FIG. 11

illustrates a different perspective view of the front housing depicted in

FIGS. 7-10

together with the detent clip and the signal clip, representing an embodiment of the invention.





FIG. 12

illustrates a perspective view of the cam body, the detent clip, and the signal clip, representing an embodiment of the invention.





FIG. 13

illustrates a perspective view of the cam body, the detent clip, the signal clip, and the detachable antenna, representing an embodiment of the invention.





FIG. 14

illustrates a perspective view of the cam body, the detachable antenna, and a circuit board with an electrical contact switch, representing an embodiment of the invention.





FIG. 15

illustrates a perspective view of the cam body, the detachable antenna, the circuit board with the electrical contact switch, and the signal clip, representing an embodiment of the invention.





FIGS. 16A-16C

illustrate orthographic views of the signal clip, representing an embodiment of the invention.





FIGS. 17A-17C

illustrate orthographic views of the detent clip, representing an embodiment of the invention.





FIG. 18

illustrates an orthographic view of the inside of the front housing of the wireless communications device, representing an embodiment of the invention.





FIG. 19

illustrates an orthographic view of the front housing depicted in

FIG. 18

with the cam body in position, representing an embodiment of the invention.





FIG. 20

illustrates an orthographic view of the front housing depicted in

FIGS. 18-19

with the detent clip, and the signal clip in position, representing an embodiment of the invention.





FIG. 21

illustrates a perspective view of a wireless communications device with a detachable antenna removed a short distance and orientated at approximately 180 degrees, representing an embodiment of the invention.





FIGS. 22A-22B

illustrate orthographic views of a single clip with engagement nipple, representing an embodiment of the invention.





FIG. 23

illustrates a schematic diagram of a circuit that includes an impedance matching branch, representing an embodiment of the invention.











DESCRIPTION OF PREFERRED EMBODIMENTS




The invention and the various features and advantageous details thereof are explained more fully with reference to the nonlimiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. Descriptions of well known components and processing techniques are omitted so as not to unnecessarily obscure the invention in detail.




The context of the invention is radio frequency (RF) communications between wireless communications devices. The RF communications can be analog or digital. The RF communications can be spread spectrum. The wireless communications devices can include a personal data assistant (e.g., computer with a touch sensitive screen, also known as (aka) a pen based computer).




The invention can also utilize data processing methods that convert a change in the detachable antenna position to a transformation of one, or more, electrical signals so as to actuate interconnected discrete hardware elements; for example, to couple electrical power to a display on a wireless communications device when the detachable antenna is deflected through an angular position. Another example would be to disable the transmitting function of a wireless communications device when the detachable antenna is removed from the wireless communications device, and re-enable the transmitting function when the detachable antenna is replaced.




Referring to

FIG. 1

, a detachable antenna


110


is mechanically coupled to a wireless communications device


120


. Although the embodiment shown in

FIG. 1

is based on the wireless communications device


120


, it is within the level of ordinary skill in the art after having knowledge of the invention disclosed herein to combine the detachable antenna


110


with any static or mobile communications device, for instance, a receiver (such as a pager), a transmitter (such as a transponder), or a transceiver (such as a cellular phone).




Still referring to

FIG. 1

, the detachable antenna


110


is depicted positioned at an angular position of approximately zero degrees. The designation of the illustrated position as zero degrees, while arbitrary, can be appreciated to correspond to a closed, compact position in the context of the embodiment shown in FIG.


1


. The detachable antenna is shown in a first (e.g., off) position where the antenna is disposed along one side of the wireless communications device. The detachable antenna


110


can be radially deflected about a rotation axis


130


. From the position depicted in

FIG. 1

, this radial deflection will be clockwise with regard to a view point to the right of the wireless communications device


120


and along the rotation axis


130


. The detachable antenna


110


is user replaceable. The detachable antenna


110


can be a monopole antenna.




Still referring to

FIG. 1

, the wireless communications device


120


includes a data port


140


. The wireless communications device


120


includes an on/off (e.g., display power) switch


150


. The wireless communications device


120


includes a plurality of application buttons


160


. The application buttons


160


can also be navigational/message buttons. The wireless communications device


120


includes a scrolling button


170


. The scrolling button


170


can be a rocker switch, either a two-way rocker switch as illustrated, or a more than two-way rocker switch (e.g., a four-way rocker switch). Last, but not least, the wireless communications device


120


includes a screen


180


. The screen


180


can also be termed a display.




Referring to

FIG. 2

, the detachable antenna


110


is depicted in a deployed position of approximately 90 degrees. This position of approximately 90 degrees is relative to the position shown in

FIG. 1

which has been arbitrarily denoted as zero degrees. In order to reach the deployed position depicted in

FIG. 2

, the detachable antenna


110


is swung radially about the rotation axis


130


, in a clockwise direction with regard to a viewpoint taken from the right of the wireless communications device


120


along the rotation axis


130


. It should be noted that the movement of the detachable antenna


110


through an angular position (e.g., 70 degrees) can actuate one, or more, features of the wireless communications device


120


(e.g., turn on the power to the display). However, it should be noted that this actuation feature is optional.




Still referring to

FIG. 2

, the wireless communications device


120


includes a closure ridge


210


. It can be appreciated that the detachable antenna


110


rests against the closure ridge


210


when the detachable antenna


110


is not in a deployed condition. The detachable antenna cannot be deflected in a counter-clockwise direction, with regard to a viewpoint to the right of the wireless communications device


120


and along the rotation axis


130


, when the detachable antenna rests against the closure ridge


210


. Thus, the closure ridge


210


functions as a stop for the detachable antenna.




Still referring to

FIG. 2

, the closure ridge


210


includes a ridge recess


215


. The ridge recess


215


is formed in the closure ridge


210


. In this embodiment, the closure ridge


210


has had some of the material removed from the lower half of the closure ridge


210


. The purpose of the ridge recess


215


is to provide clearance for a finger (e.g., thumb) to more easily contact the bottom edge of the detachable antenna


110


and deflect the detachable antenna


110


in a clockwise direction when the detachable antenna is positioned against the closure ridge


210


. This allows an operator to more easily grasp the lower edge of the detachable antenna


110


when the detachable antenna


110


is in a closed (i.e., 0 degree) position




Referring to

FIG. 3

, the detachable antenna


110


is depicted in a deployed position of approximately 135 degrees. To be deployed in the position depicted in

FIG. 3

, the detachable antenna


110


is swung into this position by rotation about the rotation axis


130


. A detent mechanism within the wireless communications device


120


can exert a restorative force against the detachable antenna


110


that helps to keep the detachable antenna in this


135


degree position. Such a restorative force can be exerted against the detachable antenna


110


at other angular positions (e.g., 90 and 180 degrees, and multiples thereof). The detent mechanism will be discussed below in more detail.




Still referring to

FIG. 3

, a rib


310


is located at the upper end of the detachable antenna


110


. The rib


310


is for frictional engagement with the finger of an operator, thereby providing a better grip when deflecting the detachable antenna


110


. The rib


310


protrudes from the side of the detachable antenna


110


.




Referring to

FIG. 4

, the detachable antenna


110


is depicted in a deployed position of approximately 180 degrees. The detachable antenna


110


is deployed to the position of approximately 180 degrees by radially swinging the detachable antenna


110


about the rotation axis


130


. In this position, the detachable antenna


110


can be manually removed from the wireless communications device


120


, without tools.




Still referring to

FIG. 4

, the detachable antenna


110


can be removed from the wireless communications device


120


without tools by aligning the detachable antenna


110


with the 180 degree position and then moving the detachable antenna


110


away from the wireless communications device


120


along a direction perpendicular to the rotation axis


130


. This movement away from the wireless communications device


120


may require enough force to overcome a snap-fit retainment mechanism within the wireless communications device


120


. Further, the detachable antenna


110


can then be reattached to the wireless communications device


120


without tools by aligning the detachable antenna


110


with the 180 degree position and moving the detachable antenna


110


toward the wireless communications device


120


along the rotation axis


130


. This movement toward the wireless communications device


120


may require enough force to overcome the resistance presented by the snap-fit retainment mechanism. The snap-fit retainment mechanism will be discussed in more detail below.




Still referring to

FIG. 4

, it should be noted that the removal and/or replacement feature(s) of the detachable antenna


110


can provided at any angular position, and not necessarily with just the 180 degree position. For example, in other embodiments, the option to remove and/or replace the detachable antenna


110


can be provided at a 270 degree position instead of, or in addition to, the 180 degree position.




Still referring to

FIG. 4

, the removal of the detachable antenna


110


from the wireless communications device


120


can actuate one, or more, features of the wireless communications device


120


(e.g., disable the transmitting function(s) of the wireless communications device


120


to prevent damage to the electronic circuits). However, this disable feature, or any other actuation associated with removal of the detachable antenna


110


is optional. Similarly, replacement of the detachable antenna


110


can actuate one, or more, features of the wireless communications device


120


(e.g., enable the transmitting function(s)). The removal and reattachment of the detachable antenna


110


will be discussed below in more detail. As above, this enable feature, or any other actuation associated with replacement of the detachable antenna


110


is optional. It should be noted that any actuation features associated with removal and/or replacement of the detachable antenna


110


can be provided at any angular positions that correspond to the ability to remove and/or replace the detachable antenna


110


, and not necessarily only at the 180 degree position.




Referring to

FIG. 21

, another detachable antenna


2110


is depicted a short distance away from the wireless compunctions device


120


. The detachable antenna


2110


includes a ridge


2120


. The ridge is located adjacent ridge recess


215


in the closure ridge


210


when the detachable antenna


2110


is in the 0 degree position. The ridge


2120


in the detachable antenna


2110


starts flush at one end and rises from the detachable antenna


2110


and then recedes back so as to be flush with the detachable antenna


2110


. The ridge


2120


of the detachable antenna


2110


shown in

FIG. 5

provides a larger frictional structure for an operator's finger to engage than the rib


310


of the detachable antenna


110


shown in

FIGS. 3-4

. An important feature of the invention is that either the detachable antenna


110


(

FIGS. 1-4

) or the detachable antenna


2110


(

FIG. 21

) can be engaged with the wireless communications device


120


.




Referring again to

FIG. 21

, the ridge


2120


is a protrusion that is formed so as to stand proud from side of the detachable antenna


2110


. Namely, the bottom edge of the detachable antenna


2110


has a radius of curvature having a first value near the rotation axis


130


. The radius of curvature changes to a second, smaller value along the interval defined by the ridge


2120


. The radius of curvature reverts to the first value near the free end of the detachable antenna


2110


. Further, The ridge


2120


can be termed a protrusion with a large arc. The protrusion is made by a circular type section that is made to join with the bottom edge of the antenna body and the radius is swept along the bottom edge profile of the antenna. The radius of curvature defined by the bottom edge of the detachable antenna


2110


changes by decreasing in value as a section of interest moves onto the protrusion.




Still referring to

FIG. 21

, it can be appreciated that the detachable antenna


2110


must be properly positioned with wireless communications device


120


as the detachable antenna


2110


is to be removed (vectored away) from the balance of the wireless communications device


120


. The converse is equally applicable when the detachable antenna is to be reattached (vectored toward) to the balance of the wireless communications device


120


. The position of the antenna with respect to the balance of the wireless compunctions device


120


will be discussed below in more detail.




Referring to

FIG. 5

, a front housing


510


from the wireless communications device


120


is depicted. In this view, the detachable antenna (not shown in

FIG. 5

) has been detached. Replacement of the detachable (e.g., discardable) antenna for the purpose of repair or upgrade can be accomplished by simply pulling the discardable antenna out and snapping in a new antenna.




Still referring to

FIG. 5

, a cam body


520


is mechanically coupled to the front housing


510


. The cam body


520


can be rotated within the front housing


510


about the rotation axis


130


. The front housing


510


includes an antenna keyway


530


. The cam body


520


includes an antenna key pin slot


540


. The antenna keyway


530


and the antenna key pin slot thus combine to define a slot having a short side and a long side. The antenna keyway is adapted to mate with a key pin


630


(shown in FIG.


6


), so that the key pin


630


can only be placed within the cam body


520


in one particular orientation, for snap-out removal and snap-in insertion of the detachable antenna. The antenna keyway


530


is disposed on a side of the front housing


510


near the top of the wireless communications device


120


.




Still referring to

FIG. 5

, the antenna key pin slot


540


includes notches


550


that indicate the correct position of the cam body


520


with regard to the front housing


510


for reattachment of the detachable antenna (not shown). The notches


550


must be aligned with the antenna keyway


530


when the detachable antenna is attached. If the notches


550


are not aligned with the antenna keyway


530


, the detents and the actuation zone may be out of phase (e.g., by 180 degrees). The notches


550


in the cam body


520


are markers and are to be aligned with the antenna keyway


530


before inserting the detachable antenna so the detachable antenna is not 180 degrees out of phase. Thus, when the cam body


520


is in the position depicted in

FIG. 5

, the notches


550


are not aligned with the antenna keyway


530


, and the detachable antenna (not shown) may, or may not, be detachable from, or reattachable to the front housing


510


, but the detachable antenna


110


may not be operable in all respects. More specifically, the optional display power up feature may not be actuated when the detachable antenna


110


is deflected clockwise through the 70 degree position. The reasons for this will discussed below in more detail.




Referring now to

FIGS. 1-6

, the detachable antenna


110


is shown in more detail. The detachable antenna


110


includes an antenna body


610


. With regard to the rest of the wireless communications device


120


, the antenna body


610


has a length approximately that of the distance between the bottom of the screen


180


to the top of the wireless communications device


120


. The antenna body


610


has a depth adapted to fit along the edge of the wireless communications device


120


, and a width corresponding to the thickness of the wireless communications device


120


. The antenna body


610


has a flat end


660


and rounded end


670


. The flat end


660


is disposed towards the bottom of the wireless communications device


120


at a position corresponding with the bottom of the screen


180


. The rounded end


670


is disposed near the top of the wireless communications device


120


. The axis of rotation for the antenna body


610


is defined by a signal pin


620


disposed near the rounded end


670


of the detachable antenna


110


. The signal pin


620


extends into the wireless communications device


120


from the antenna body


610


. A key pin


630


fits through an opening in the signal pin and extends orthogonally outward from both sides of the signal pin


620


.




Referring to

FIG. 6

, the antenna body


610


can be a rubber over mold. The rubber over mold can include a flat plate of metal encased within a synthetic polymer. The signal pin


620


can be mechanically coupled to the detachable antenna


110


so as to be substantially perpendicular to a plane defined by the antenna body


610


. The signal pin


620


can be swagged onto a flat plate that is then encased in a rubber over mold. Alternatively, a coaxial cable can be embedded instead of a flat sheet, or a plain round wire can be used. The signal pin


620


has two primary functions. First, the signal pin


620


acts as a conduit for a communications signal (e.g., a radio frequency signal). Second, the signal pin


620


acts as a pivot around which the detachable antenna


110


can rotate.




Still referring to

FIG. 6

, the key pin


630


is mechanically coupled to the signal pin


620


. The key pin


630


can pass through the signal pin


620


substantially perpendicular to a center line defined by the signal pin


620


. In this way, a plane defined by the key pin


630


can be substantially parallel to the plane defined by the antenna body


610


. A first end


640


of the key pin


630


can protrude from the signal pin


620


. Similarly, a second end


650


of the key pin


630


can protrude from the signal pin


620


. In the embodiment depicted in

FIG. 6

, the first end


640


of the key pin


630


protrudes from the signal pin


620


further than the second end


650


. Thus, the first end


640


of the key pin


630


must be aligned with the antenna keyway


530


shown in

FIG. 5

for the key pin


630


to be inserted into the cam body


520


. The key pin


630


is offset so it can only be inserted into the front housing


510


in one position. This provides a locking feature when the detachable antenna is rotated out of an insert position (e.g., 180 degrees).




Referring to

FIG. 7

, a view of the inside of the front housing


510


is depicted. The front housing


510


includes a cam body hole


710


. The cam body (not shown in

FIG. 7

) fits in the cam body hole


710


and can be rotated therein. The front housing


510


includes a detent clip screw boss


720


. A detent clip (not shown in

FIG. 7

) is secured to the detent clip screw boss


720


. The front housing


510


includes a detent clip alignment leg notch


730


. An alignment leg on the detent clip fits in the detent clip alignment leg notch


730


. The front housing


510


includes a signal pin hole


740


. The signal pin of the detachable antenna (not shown in

FIG. 7

) fits through the signal pin hole


740


. The front housing


510


includes a signal clip barb notch


750


. A signal clip (not shown in

FIG. 7

) fits in the signal clip barb notch


750


.




Referring to

FIG. 8

, a cam body


520


is depicted positioned within the front housing


510


. The cam body


520


fits in the cam body hole


710


. The cam body


520


can be a single coaxial cam body. The cam body


520


defines a central axis that is coaxial with both the cam body hole


710


and the signal pin hole


740


. The cam body


520


is free to rotate about its axis within the front housing


510


. It should be noted that the cam body


520


has a plurality of zones, each of which is adapted to a primary purpose. In the depicted embodiment, there are three primary zones. Although one of the functions of the cam body


520


is to provide a cam surface


815


, the cam body


520


has other, noncam functions. For example, with regard to the orientation presented in

FIG. 8

, the left most portion of the cam body


520


defines a circular bearing surface


820


that rides within the cam body hole


710


. The circular bearing surface


820


functions to keep the cam body


520


in alignment. As another example, the cam body


520


includes a detent surface


825


. The detent surface


825


functions in cooperation with a detent clip (not shown in

FIG. 8

) to help hold the angular position of the cam body


520


. The cam body


520


provides all of the functions of fixing, indexing, and actuating.




Referring to

FIG. 9

, a detent clip


910


is depicted in mechanical engagement with the cam body


520


. The detent clip


910


is in engagement with, and exerts a force against, the detent surface


825


of the cam body


520


. The detent clip


910


is mechanically coupled to the front housing


510


. A screw hole


920


in the detent clip


910


is aligned with the detent clip screw boss


720


. A screw or bolt (not shown in

FIG. 9

) can be inserted through the screw hole


920


and secured to the detent clip screw boss


720


, thereby holding the detent clip


910


against the detent clip screw boss


720


. The detent clip


910


includes a detent alignment leg


930


that is in frictional engagement with the front housing


510


. The detent alignment leg


930


on the detent clip


910


is inserted into the detent clip alignment leg notch


730


, thereby keeping the detent clip from rotating when the screw or bolt is tightened.




Referring to

FIG. 10

, a signal clip


1010


is mechanically coupled to the front housing


510


. The signal clip


1010


can also be termed a contact clip. The signal clip


1010


includes a circuit board contact


1020


. The signal clip


1010


includes a signal pin contact


1030


. The signal pin contact


1030


is in mechanical engagement with, and exerts a force against, the signal pin (not shown in FIG.


10


). A signal clip barb


1060


of the signal clip


1010


fits in the signal clip barb notch


750


. The signal clip


1010


includes a retaining hook


1040


that is in frictional engagement with the front housing


510


. The retaining hook


1040


of the signal clip


1010


fits in the signal clip retaining hook notch


760


. The coaction of the retaining hook


1040


and the signal clip barb notch


750


of the front housing


510


keeps the signal clip


1010


flush against an alignment wall


1050


. All of the parts shown in

FIG. 10

can be replaced.




Referring to

FIG. 11

, a slightly different perspective on the front housing


510


, the cam body


520


, the detent clip


910


and the signal clip


1010


is depicted. It can be appreciated that the subassembly is compact and structurally integrated.




Referring to

FIG. 12

, the cam body


520


will now be described in more detail. The cam body


520


includes a retaining zone


1210


. The retaining zone includes the circular bearing surface


820


and the antenna key pin slot


540


. The cam body


520


includes an indexing zone


1220


. The indexing zone


1220


includes the detent surface


825


. The cam body


520


includes a micro switch activation zone


1230


. The micro switch activation zone


1230


includes the cam surface


815


. The retaining zone


1210


, the indexing zone


1220


, and the micro switch activation zone


1230


are coaxial and provide the cam body


520


with three discreet functions. The detent clip


910


is depicted in mechanical engagement with the detent surface


825


of the indexing zone


1220


in FIG.


12


.




Still referring to

FIG. 12

, the function of the retaining zone


1210


is to hold the key pin (not shown in

FIG. 12

) of the detachable antenna (not shown in

FIG. 12

) when the detachable antenna is attached to the wireless communications device (not shown in FIG.


12


). The function of the indexing zone


1220


is to help maintain particular angular positions of the cam body


520


with regard to the wireless communications device. The angular alignment of the cam body


520


can be resistably fixed in a plurality of positions by the coaction of the detent clip


910


with the plurality of parallel slots


1240


that are arranged on the outer circumference of the indexing zone


1220


. The plurality of parallel slots


1240


can be located so that the detachable antenna


110


will exhibit a resistance to moving from various angular positions (e.g., 90, 135, 180 degrees). The function of the micro switch activation zone


1230


is to actuate an electrical contact switch (not shown in

FIG. 12

) so as to conduct an RF signal to and/or from the signal pin (not shown in

FIG. 12

) of the detachable antenna. A lobe


1250


on the cam body


520


activates the electrical contact switch to indicate that the detachable antenna is engaged. If the unit is off, engaging the antenna will turn the unit on.




Referring to

FIG. 13

, the cam body


520


, the detent clip


910


, and the signal clip


1010


are depicted in combination with the detachable antenna


110


. It can be appreciated that the signal pin


620


passes through the cam body


520


and is in both mechanical and electrical contact with the signal clip


1010


. The signal slip


1010


exerts a small force against the signal pin


620


. It can also be appreciated that the key pin


630


is in a snap fit engagement with the retaining zone


1210


. The key pin


630


snaps into the slot


540


in the retaining zone


1210


of the cam body


520


. Upon insertion of the detachable antenna


110


into the cam body


520


, movement of the signal pin


620


through the cam body


520


is stopped by the detachable antenna


110


coming flush with the retaining zone


1210


of the cam body


520


. Thus, rotation of the detachable antenna


110


will cause rotation of the cam body


520


. The first end


640


of the key pin


630


protrudes beyond the outer circumference defined by the retaining zone


1210


. It can be appreciated that the detents are used for locking the antenna in place and are also used in removing the detachable antenna


110


. The detachable antenna


110


can be of a length between


{fraction (1/2+L )} wave and




{fraction (1/4+L )} wave, and yet function like a




{fraction (1/2+L )} wave due to the length of the circuitry within the wireless communications device 120. Part of the length that makes the detachable antenna 110 function like a




{fraction (1/2+L )} wave antenna comes from the length of the signal pin 620 and the length of the signal clip 1010.






Referring to

FIG. 14

, the detachable antenna


110


and the cam body


520


are depicted in combination with a PCB


1410


. The PCB


1410


is a circuit board. The PCB


1410


includes a micro switch


1420


. The micro switch


1420


includes a plunger


1430


. The plunger


1430


is in mechanical engagement with the cam surface


815


of the micro switch activation zone


1230


. It can be appreciated that rotation of the detachable antenna


110


will cause rotation of the micro switch activation zone


1230


, thereby changing the extent to which the piston protrudes from the micro switch


1420


in the same way that a cam follower moves in relation to a cam. In the embodiment depicted in

FIG. 14

, the micro switch


1420


is in a noncontact (nonconductive) state when the piston


1430


is in contact with the low point of the micro switch activation zone


1230


.




Still referring to

FIG. 14

, the PCB


1410


includes a contact pad


1440


. The contact pad


1440


is electrically coupled to circuitry on the PCB


141




0


via the microswitch


1420


. The contact pad


1440


can be square, round, rectangular, or any other shape and should present a substantially planar upper surface. The contact pad


1440


includes a recess


1450


. The recess


1450


can be circular and/or pass all the way through the contact pad


1440


so as to define a hole.




Referring to

FIG. 15

, the detachable antenna


110


, the cam body


520


, and the PCB


1410


are depicted in combination with the signal clip


1010


. The electrical contact


1020


of the signal clip


1010


is adjacent and electrically coupled to the contact pad


1440


. The recess


1450


(not shown in

FIG. 15

) is obscured by the electrical contact


1020


of the signal clip


1010


. It can be appreciated that the micro switch


1420


can be connected in electrical series with the electrical contact


1020


of the signal clip


1010


. Thus, the angular position of the detachable antenna


110


can be used to control the electrical contact state between the signal pin


630


and the PCB


1410


via the micro switch


1420


.




Referring to

FIGS. 16A-16C

, three orthographic views of the signal clip


1010


are depicted. With regard to the inside of the front housing (not shown in FIGS.


16


A-


16


C),

FIG. 16A

illustrates a top view of the signal clip


1010


.

FIG. 16B

illustrates a side view of the signal clip


1010


looking toward the signal pin (not shown in FIGS.


16


A-


16


C).

FIG. 16C

shows an upside down side view of the signal clip


1010


looking away from the cam body (not shown in FIG.


16


C). The signal clip barb


1060


is wedged into the signal clip barb notch


750


(not shown in FIGS.


16


A-


16


C).




Referring to

FIGS. 17A-17C

, three orthographic views of the detent clip


910


are depicted. With regard to the inside of the front housing (not shown in FIGS.


17


A-


17


C),

FIG. 17A

depicts a top view of the detent clip


910


.

FIG. 17B

depicts a side view of the detent clip


910


looking toward the detachable antenna (not shown in FIG.


17


B).

FIG. 17C

shows an upside down side view of the detent clip


910


looking away from the cam body (not shown in FIG.


17


C).





FIG. 18

depicts an orthographic top view of the inside of the front housing


510


. It can be appreciated that the detent clip alignment leg notch


730


provides an alignment function with regard to the detent clip (not shown in FIG.


18


). Similarly, it can be appreciated that the signal clip barb notch


750


provides an alignment function with regard to the signal clip (not shown in FIG.


18


).





FIG. 19

depicts an orthographic top view of the inside of the front housing


510


with the detachable antenna


110


and the cam body


520


in position. It can be appreciated that the signal pin


630


of the detachable antenna passes through and protrudes beyond the cam body


520


so as to be an electrical conduction with the signal clip (not shown in FIG.


19


).




Referring to

FIG. 20

, an orthographic top view of the inside of the front housing


510


is depicted in combination with the signal clip


1010


, the detent clip


910


and a portion of the detachable antenna


110


(the signal pin of the detachable antenna


110


is not depicted in FIG.


20


). It can be appreciated from the viewpoint shown in

FIG. 20

that the signal clip


1010


and the detent clip


910


are held in place with a minimum of fasteners.




Referring to

FIGS. 22A-22B

, two orthographic views of a signal clip


2200


are depicted. With regard to the inside of the front housing (not shown in FIGS.


22


A-


22


B),

FIG. 22B

illustrates a top view of the signal clip


2200


.

FIG. 22A

illustrates a side view of the signal clip


2200


looking toward the signal pin (not shown in FIGS.


22


A-


22


B). The signal clip


2200


includes a signal clip barb


2260


that is wedged into the signal clip bar notch


705


(not shown in FIGS.


22


A-


22


B). The signal clip


2200


includes an electrical contact


2220


. The electrical contact


2220


includes a projection


2225


. The projection


2225


can be of circular cross section and semispherical profile. The projection


2225


can be termed an engagement nipple. The projection


2225


can be adapted to frictionally engage with the recess


1450


of contact pad


1440


(shown in FIG.


14


). The cooperation of the projection


2225


and the recess


1450


can provide an electrical contact surface having a greater surface area than if these two structural features were absent. This results in lower ohmic resistance. In addition, the cooperation of these two structural features helps to maintain electrical continuity even when the combined structure is undergoing vibration or impact.




The signal clip


2200


can be pushed into the housing of the wireless communications device so as to provide a signal path from the main printed circuit board


1410


to the antenna signal pin


620


and vice-a-versa. The construction of the clip (geometry and choice of materials) allows for easy assembly of the subcomponents. Additionally, the contact pad


1440


provides a test point on the printed circuit board


1410


for manufacturing testing when the signal clip


2200


is not installed (i.e., detachably connected to the contact pad). Once the signal clip


2200


is installed and assembled into the housing, the signal clip


2200


maintains signal integrity without influencing the voltage standing wave ratio (VSWR). The voltage standing wave ratio is defined as output power divided by reflected power, where the output power plus the reflected power equals unity. The size of the contact pad is minimized to achieve a small form factor and thinness of resulting device while still providing reliable and relatively loss-less connectivity. However, in spite of the presence of the projection


2225


and the recess


1450


, the electrical coupling between the signal clip


2200


and the contact pad


1440


inherently creates a contact resistance. This contact resistance may be termed an impedance mismatch. To maximize VSWR, the contact pad resistance should be matched to the standard 50 ohm impedance.




Referring now to

FIG. 23

, an electrical schematic is shown depicting a number of the structural components that can compose PCB


1410


. The contact pad


1440


is electrically coupled to an inductor


2310


. In one embodiment, the inductor


2310


has a value of approximately 6.8 nanohenry. A capacitor


2320


is electrically coupled to both the contact pad


1440


and the inductor


2310


at a node


2330


located between the contact pad


1440


and the inductor


2310


. In one embodiment the capacitor has a value of approximately 2.2 picofarads. A resistor


2340


is coupled to the capacitor


2320


. In one embodiment, the resister has a value that results in a voltage of approximately 50 volts at the capacitor


2320


. Together, the inductor


2310


, the capacitor


2320


, the resistor


2340


and the interconnections thereof define an impedance matching circuit.




Practical Applications of the Invention




A practical application of the invention that has value within the technological arts is as an antenna on a wireless communications device. Further, the invention is useful in conjunction with cellular telephones (such as are used for the purpose of voice communications), or in conjunction with satellite signal reception (such as are used for the purpose of global positioning), or the like. There are virtually innumerable uses for the invention, all of which need not be detailed here.




Advantages of the Invention




A detachable antenna, representing an embodiment of the invention, can be cost effective and advantageous for at least the following reasons. The detachable antenna is user replaceable. The detachable antenna is based on a compact design. The detachable antenna is easy to replace, without tools. The detachable antenna itself has no moving parts. As a result, all of the functionality is inside the housing, protected from the user. In some embodiments, the antenna can only can replaced/removed in a specific orientation (e.g., at 180 degrees). The cam surface activates a microswitch to tell the unit that the antenna has been deployed and turns on the unit. This happens at about 75 degrees. Also, detents are built into the cam body that give the user feedback when the antenna is at 90, 135 and 180 degrees. The cam body, detent clip and signal clip can be replaced if one or all cease to function properly or wear out.




All the disclosed embodiments of the invention described herein can be realized and practiced without undue experimentation. Although the best mode of carrying out the invention contemplated by the inventors is disclosed above, practice of the invention is not limited thereto. All the disclosed elements and features of each disclosed embodiment can be combined with, or substituted for, the disclosed elements and features of every other disclosed embodiment except where such elements or features are mutually exclusive.




It will be manifest that various additions, modifications and rearrangements of the features of the invention may be made without deviating from the spirit and scope of the underlying inventive concept. It is intended that the scope of the invention as defined by the appended claims and their equivalents cover all such additions, modifications, and rearrangements. The appended claims are not to be interpreted as including means-plus function limitations, unless such a limitation is explicitly recited in a given claim using the phrase “means-for.”



Claims
  • 1. A detachable antenna assembly, comprising:a signal pin including a first signal pin end and a second signal pin end; an antenna conductively coupled to said first signal pin end; and a signal clip including a signal pin contact and a circuit board contact having a protrusion, said signal pin contact detachably connected to said second signal pin end; and a printed circuit board including a contact pad having a recess, said contact pad detachably connected to said circuit board contact and said protrusion located at least in part within said recess.
  • 2. The detachable antenna assembly of claim 1, wherein the printed circuit board includes an impedance matching circuit electrically coupled to said contact pad.
  • 3. The detachable antenna assembly of claim 1, further comprising a cam body surrounding at least a portion of said signal pin and defining a rotation axis, said cam body including a retaining zone having a snap-fit receptacle.
  • 4. The detachable antenna assembly of claim 3, further comprising a key pin that extends from said signal pin, said key pin i) having a first key pin end and a second key pin end, and ii) being snap-fit into said snap-fit receptacle.
  • 5. The detachable antenna assembly of claim 4, wherein said first key pin end extends from said signal pin so as to define a key length, and said second key pin end extends from said signal pin so as to define a distance that is shorter than said key length.
  • 6. The detachable antenna assembly of claim 5, further comprising a housing mechanically coupled to said cam body so that said cam body can be rotated around said rotation axis, wherein said housing includes a keyway that provides clearance for said key length.
  • 7. The detachable antenna assembly of claim 6, wherein said retaining zone includes an alignment notch.
  • 8. The detachable antenna assembly of claim 4, wherein said cam body includes an indexing zone.
  • 9. The detachable antenna assembly of claim 8, wherein said signal pin passes through said indexing zone.
  • 10. The detachable antenna assembly of claim 8, wherein said indexing zone defines a detent surface, and, further comprising a detent clip mechanically coupled to said detent surface.
  • 11. The detachable antenna assembly of claim 10, wherein said detent clip includes an alignment leg.
  • 12. The detachable antenna assembly of claim 4, wherein said cam body includes an activation zone.
  • 13. The detachable antenna assembly of claim 12, wherein said signal pin passes through said activation zone.
  • 14. The detachable antenna assembly of claim 12, wherein said activation zone defines a cam surface, and, further comprising a follower mechanically coupled to said cam surface.
  • 15. The detachable antenna assembly of claim 14, further comprising a contact switch mechanically coupled to said follower, wherein an electrical state of said contact switch to controlled by a position of said follower.
  • 16. The detachable antenna assembly of claim 15, wherein said printed circuit board is conductively coupled to said contact switch.
  • 17. The detachable antenna assembly of claim 4, wherein said signal pin passes through said cam body, and, further comprising a signal clip conductively coupled to said second end of said signal pin.
  • 18. The detachable antenna assembly of claim 17, wherein said signal clip includes a retaining hook.
  • 19. A wireless communications device, comprising:a signal pin including a first signal pin end and a second signal pin end; an antenna conductively coupled to said first signal pin end; and a signal clip including a signal pin contact and a circuit board contact having a protrusion, said signal pin contact detachably connected to said second signal pin end; and a printed circuit board including a contact pad having a recess, said contact pad detachably connected to said circuit board contact and said protrusion located at least in part within said recess.
  • 20. The wireless communication device of claim 19, wherein the printed circuit board includes an impedance matching circuit electrically coupled to said contact pad.
  • 21. The wireless communication device of claim 19, further comprising a cam body surrounding at least a portion of said signal pin and defining a rotation axis, said cam body including a retaining zone having a snap-fit receptacle.
  • 22. The wireless communications device of claim 21, further comprising a key pin that extends from said signal pin, said key pin i) having a first key pin end and a second key pin end, and ii) being snap-fit into said snap-fit receptacle.
  • 23. The wireless communications device of claim 22, wherein said first key pin end extends from said signal pin so as to define a key length, and said second key pin end extends from said signal pin so as to define a distance that is shorter than said key length.
  • 24. The wireless communications device of claim 23, further comprising a housing mechanically coupled to said cam body so that said cam body can be rotated around said rotation axis, wherein said housing includes a keyway that provides clearance for said key length.
  • 25. The wireless communications device of claim 24, wherein said retaining zone includes an alignment notch.
  • 26. The wireless communications device of claim 22, wherein said cam body includes an indexing zone.
  • 27. The wireless communications device of claim 26, wherein said signal pin passes through said indexing zone.
  • 28. The wireless communications device of claim 26, wherein said indexing zone defines a detent surface, and, further comprising a detent clip mechanically coupled to said detent surface.
  • 29. The wireless communications device of claim 28, wherein said detent clip includes an alignment leg.
  • 30. The wireless communications device of claim 22, wherein said cam body includes an activation zone.
  • 31. The wireless communications device of claim 30, wherein said signal pin passes through said activation zone.
  • 32. The wireless communications device of claim 30, wherein said activation zone defines a cam surface, and, further comprising a follower mechanically coupled to said cam surface.
  • 33. The wireless communications device of claim 32, further comprising a contact switch mechanically coupled to said follower, wherein an electrical state of said contact switch to controlled by a position of said follower.
  • 34. The wireless communications device of claim 32, wherein said printed circuit board is conductively coupled to said contact switch.
  • 35. The wireless communications device of claim 22, wherein said signal pin passes through said cam body, and, further comprising a signal clip conductively coupled to said second end of said signal pin.
  • 36. The wireless communications device of claim 35, wherein said signal clip includes a retaining hook.
CROSS-REFERENCE TO RELATED APPLICATION

This application is a divisional/continuation-in-part under 35 U.S.C. §120 of copending U.S. Ser. No. 09/114,439, filed Jul. 13, 1998, now U.S. Pat. No. 6,064,342 the entire contents of which are hereby incorporated herein by reference as if fully set forth herein.

US Referenced Citations (6)
Number Name Date Kind
5440315 Wright et al. Aug 1995
5617106 Tahmassebpur Apr 1997
5640689 Rossi Jun 1997
5734716 Kulberg Mar 1998
5752204 Epperson et al. May 1998
6064342 Sandhu et al. May 2000
Continuation in Parts (1)
Number Date Country
Parent 09/114439 Jul 1998 US
Child 09/261075 US