Wireless device reconfigurable radiation desensitivity bracket systems and methods

Information

  • Patent Grant
  • 7394430
  • Patent Number
    7,394,430
  • Date Filed
    Tuesday, September 14, 2004
    19 years ago
  • Date Issued
    Tuesday, July 1, 2008
    15 years ago
Abstract
A wireless communications device reconfigurable radiation desensitivity bracket, and associated reconfigurable radiation desensitivity method are provided. The method includes: generating a radiated wave at a first frequency; in response to generating the radiated wave at the first frequency, creating a maximum current per units square (I/units2) through a minimal area of an electrical circuit groundplane; generating a radiated wave at a second frequency; in response to generating the radiated wave at the second frequency, maintaining the maximum I/units2 through the minimal area of the groundplane. Alternately stated, the method controls the distribution of current flow through a groundplane, responsive to radiated emissions, as the wireless device changes operating frequency or communication band. More specifically, the method maintains the maximum I/units2 through the minimal area of the groundplane by coupling the groundplane to a bracket having a selectable effective electrical length.
Description
BACKGROUND OF THE INVENTION

1. Field of the Invention


This invention generally relates to wireless communication and, more particularly, to wireless communication antennas.


2. Description of the Related Art


The size of portable wireless communications devices, such as telephones, continues to shrink, even as more functionality is added. As a result, the designers must increase the performance of components or device subsystems and reduce their size, while packaging these components in inconvenient locations. One such critical component is the wireless communications antenna. This antenna may be connected to a telephone transceiver, for example, or a global positioning system (GPS) receiver.


Wireless communications devices are known to use simple cylindrical coil or whip antennas as either the primary or secondary communication antennas. Inverted-F antennas are also possible. Many conventional wireless telephones use a monopole or single-radiator design with an unbalanced signal feed. This type of design is dependent upon the wireless telephone printed circuit board groundplane or housing or both to act as the counterpoise. A single-radiator design acts to reduce the overall form factor of the antenna. However, the counterpoise is susceptible to changes in the design and location of proximate circuitry, and interaction with proximate objects when in use, e.g., placed on a metallic desk, or the manner in which the telephone is held. As a result of the susceptibility of the counterpoise, the radiation patterns and communications efficiency can be detrimentally impacted. Even if a balanced antenna is used, so that the groundplanes of proximate circuitry are not required as an antenna counterpoise, radiation pattern and radiation-susceptible circuitry issues remain.


This problem is compounded when an antenna, or a group of antennas operate in a plurality of frequency bands. State-of-the-art wireless telephones are expected to operate in a number of different communication bands. In the US, the cellular band (AMPS), at around 850 megahertz (MHz), and the PCS (Personal Communication System) band, at around 1900 MHz, are used. Other communication bands include the PCN (Personal Communication Network) and DCS at approximately 1800 MHz, the GSM system (Groupe Speciale Mobile) at approximately 900 MHz, and the JDC (Japanese Digital Cellular) at approximately 800 and 1500 MHz. Other bands of interest are GPS signals at approximately 1575 MHz, Bluetooth at approximately 2400 MHz, and wideband code division multiple access (WCDMA) at 1850 to 2200 MHz.


To dampen the effects of radiation upon proximate circuitry it is known to attach so-called bracket, or radiation-parasitic, elements to a groundplane. Typically, these “brackets” are used to evenly distribute current through the groundplane associated with a radiated wave. Alternately stated, the brackets are used to prevent any particular spot on a circuit board, housing, or keyboard from becoming too sensitive to radiation-induced current. It is difficult, if not impossible, to design a wireless device to minimize the interaction between antenna radiation and susceptible circuitry in every one of its communication bands. As a result, a conventional design must be optimized for one particular communication band, or the design must be compromised to in one or more communication bands of interest.


It would be advantageous if the radiation-induced current sensitivity of a wireless communications device groundplane could be minimized for every frequency of operation.


It would be advantageous if the radiation-induced current sensitivity of a wireless communications device groundplane could be tuned in response to changes in frequency, or in response to one particular groundplane area becoming too sensitive.


It would be advantageous if wireless communication device radiation desensitivity brackets could be made reconfigurable, to minimize the sensitivity of proximate circuitry at every frequency of radiation.





BRIEF DESCRIPTION OF THE DRAWINGS


FIG. 1 is a schematic block diagram of the present invention wireless communications device with a reconfigurable radiation desensitivity bracket.



FIG. 2 is a schematic block diagram of the bracket of FIG. 1.



FIG. 3 is a schematic block diagram of a first variation of the bracket of FIG. 1.



FIG. 4 is a schematic block diagram of a second variation of the bracket of FIG. 1.



FIG. 5 is a schematic block diagram of a third variation of the bracket of FIG. 1.



FIG. 6 is a schematic block diagram of a fourth variation of the bracket of FIG. 1.



FIG. 7 is a schematic block diagram illustrating a fifth variation of the bracket of FIG. 1.



FIG. 8 is a schematic block diagram of a sixth variation of the bracket of FIG. 1.



FIG. 9 is a schematic block diagram illustrating a seventh variation of the bracket of FIG. 1.



FIG. 10 is a schematic diagram illustration some combinations of series-connected and parallel-connected FELS.



FIG. 11 is a plan view schematic diagram illustrating a bracket design where a plurality of fixed electrical length sections form a matrix of adjoining conductive areas.



FIG. 12 is a perspective cutaway view illustrating a bracket housing design.



FIG. 13 is a perspective drawing illustrating some exemplary FELS variations.



FIG. 14 is a schematic block diagram of the present invention portable wireless telephone communications device with a reconfigurable radiation desensitivity bracket.



FIG. 15 is a schematic block diagram of the present invention wireless communications base station with a reconfigurable radiation desensitivity bracket.



FIGS. 16A and 16B are diagrams illustrating the present invention bracket redistributing radiation-induced current flow in a groundplane.



FIG. 17 is a flowchart illustrating the present invention method for reconfigurable radiation desensitivity in a wireless communications device.



FIG. 18 is a plan view drawing of a wireless device display bracket design.





DETAILED DESCRIPTION

The present invention describes a wireless communications device with a reconfigurable radiation desensitivity bracket that can be added to the groundplane of a circuit proximate to a radiation source such as an antenna, to minimize the effects of radiation-induced current. The bracket can be selectively tuned or switched in response to changes in frequency. Alternately considered, the bracket is space-reconfigurable to selectively redistribute current flow through the groundplane associated with radiated waves.


Accordingly, a method is provided for reconfigurable radiation desensitivity in a wireless communications device. The method comprises: generating a radiated wave at a first frequency; in response to generating the radiated wave at the first frequency, creating a maximum current per units square (I/units2) through a minimal area of an electrical circuit groundplane; generating a radiated wave at a second frequency; in response to generating the radiated wave at the second frequency, maintaining the maximum I/units2 through the minimal area of the groundplane. Alternately stated, the method controls the distribution of current flow through a groundplane, responsive to radiated emissions, as the wireless device changes operating frequency or communication band. The method is applicable to wireless device electrical circuitry such as a printed circuit board (PCB) with mounted components, a display, a connector, or a keypad.


More specifically, the method maintains the maximum I/units2 through the minimal area of the groundplane by coupling the groundplane to a bracket having a selectable effective electrical length. The coupling mechanism may be through a transistor, p/n junction coupling through a PIN diode, selectable capacitive coupling through a varactor diode or ferroelectric capacitor, or mechanically bridging through a switch or microelectromechanical system (MEMS).


Typically, the bracket has a fixed physical length section, in addition to the selectable effective electrical length section to provide a combined effective electrical length responsive to the fixed physical length and the selectable effective electrical length. Further, the bracket may include a plurality of selectable electrical length sections, a plurality of fixed physical length sections, or a plurality of both section types. The sections may be connected to the groundplane, series connected, parallel connected, or combinations of the above-mentioned connection configurations.



FIG. 1 is a schematic block diagram of the present invention wireless communications device with a reconfigurable radiation desensitivity bracket. The device 100 comprises a transmitter 102 and an antenna 104 connected to the transmitter 102. The wireless device 100 includes an electrical circuit 106 having a groundplane 108. A reconfigurable radiation desensitivity bracket 108 is coupled to the groundplane 106. Examples of the electrical circuit represented by reference designator 104 include components, such as integrated circuits (ICs), transistors, resistors, capacitors, inductors, and the like, mounted on a printed circuit board (PCB). Electrical circuit 104 can also be a display, a connector, or a keypad. The invention is not limited to any particular type of electrical circuit. In some aspects, the groundplane 106 can be the wireless device housing 110. Although the antenna 104 is typically the primary radiation source, the bracket 108 may also be used to control radiation-induced current from a source such as a transistor, resistor, inductor, integrated circuit, or the like (not shown).


Two primary uses of the present invention bracket are for use in a portable or base station wireless communications device, where circuitry is susceptible to radiating elements such as an antenna, transmitter, transmitter component such as a transistor, inductor, resistor, or changes in the environment around a radiating element, to list a few examples. Receiver circuitry, for example, may be susceptible to radiating elements. Another use for the bracket is in microprocessor-driven computing devices, such as a personal computer. Here, susceptible circuitry can be protected, using the present invention bracket, from a radiation source such as a power supply, high-speed ICs, or network interfaces.


One general purpose of the bracket 108 is to evenly distribute groundplane currents that are generated as a result of radiated emissions. For this reason, the bracket 108 is termed a radiation desensitivity bracket, as radiation-generated current flow through a groundplane often makes wireless device transceiver and antenna circuitry susceptible to proximate objects that interrupt and modify current flow patterns. That is, the bracket acts to distribute current flow so as make the groundplane less susceptible to proximate objects. In other aspects, the bracket can be used to intentionally direct radiation-induced current flow to particular areas of the groundplane, for example, to a shielded area of the groundplane that is not susceptible to proximate objects such as a user's hand or to a wall that may temporarily be in close proximity (within the near-field).



FIG. 2 is a schematic block diagram of the bracket 108 of FIG. 1. Generally, the bracket 108 has a selectable effective electrical length 200. The electrical length 200 is the measurement of wavelength, or wavelength portion. The electrical length is directly proportional to frequency, and is modified by the dielectric constant of the material through which the radiated wave travels to reach the bracket 108. For example, the bracket may be tuned to have either an electrical length 200a or electrical length 200b. As can be appreciated by those skilled in the art, the bracket, in combination with the attached groundplane, forms parasitic element that has a radiation susceptance or sensitivity that is dependent upon the frequency of radiation. That is, the interaction of a radiated wave with the groundplane/bracket combination is dependent upon the electrical length of the bracket. Every bracket 108 includes a selectable electrical length section 204 having a distal end 206, a proximal end 208, a control input on line 210 to accept control signals, and a selectable effective electrical length 200 responsive to the control signals on line 210. The bracket is termed configurable in that it may include switch elements, tunable elements, or both. As explained in detail below, the electrical length of the bracket can be manipulated using either the switchable or tunable elements.


The selectable electrical length section (SELS) 204 can be a coupling element such as FET, bipolar transistor, PIN diode, ferroelectric capacitor, varactor diode, or microelectromechanical system (MEMS) switch. The electric length of the SELS 204 is dependent upon more than just the physical length 212 of the section. That is, the coupling action of the SELS 204 includes a reactance or imaginary impedance component that can be varied to change the electrical length. Note, a MEMS switch can be used a variable air-gap capacitor by partially closing the switch.


Returning to FIG. 1, a desensitivity control circuit 111 has an input on line 113 to accept frequency selection commands and an output on line 210, connected to the selectable effective length section 204. The desensitivity control circuit 111 supplies control signals in response to the frequency selection commands. That is, the desensitivity control circuit 111 tracks the frequency selection commands sent to the transceiver 112 on line 113 and provides control signals to the bracket accordingly.


In one aspect, the transmitter 102 is a wireless telephone transmitter, part of transceiver 112 that additionally includes a receiver 114. As noted above, the transmitter (and receiver 114), or a set of transceivers 112 (not shown), may operate in a number of different communications bands, such as AMPS or PCS to name just a couple of examples. Further, the transmitter 102 may operate in number of channels within a particular communication band. Advantageously, the bracket 108 can be configured for every frequency of operation.


For example, the transmitter 102 may selectively operate at a first frequency and a second frequency. Then, the bracket 108 selectable electrical length section has a first effective electrical length, selected in response to the transmitter operating at the first frequency. The first effective electrical length may operate to evenly distribute radiation-induced ground current when the transmitter 102 operates at the first frequency. Likewise, the bracket 108 SELS has a second effective electrical length, selected in response to the transmitter 102 operating at the second frequency. The second effective electrical length may operate to evenly distribute radiation-induced current in the groundplane when the transmitter operates at the second frequency.



FIG. 3 is a schematic block diagram of a first variation of the bracket 108 of FIG. 1. In this variation, the bracket 108 further includes a fixed electrical length section (FELS) 300 having a distal end 302, a proximal end 304, and a fixed physical length 306. The combination of the selectable electrical length section 204 and the fixed electrical length section 300 provides a combined selectable effective electrical length 308 responsive to the control signal on line 210. That is, the overall electrical length 308 is a combination of the physical length 306 of the FELS 300 and the electrical length 200 of the SELS 204, which may be physical length, if enabled as a MEMS for example, or a reactance, if enabled as a varactor diode for example.



FIG. 4 is a schematic block diagram of a second variation of the bracket 108 of FIG. 1. The bracket 108 may include a plurality of selectable electrical length sections 204. Although three SELS' 204 are shown, the invention is not limited to any particular number. As shown, the SELS' 204 are connected to the groundplane 106.



FIG. 5 is a schematic block diagram of a third variation of the bracket 108 of FIG. 1. As shown, the three SELS' 204 are series-connected to the groundplane 106. Note, although the series of SELS' is shown as open-connected (unterminated), in other aspects both ends of the bracket 108 may be connected to the groundplane 106 or other circuitry (not shown). In other shown aspects not shown, the connections between individual SELS' 204 in the series may be terminated in the groundplane 106.



FIG. 6 is a schematic block diagram of a fourth variation of the bracket 108 of FIG. 1. As shown, the three SELS' 204 are parallel-connected to the groundplane 106. In other aspects not shown, both ends of one or all the SELS' 204 may be terminated in the groundplane.



FIG. 7 is a schematic block diagram illustrating a fifth variation of the bracket 108 of FIG. 1. Here, SELS 204a is connected to the groundplane 106, SELS' 204b and 204c are series-connected to the groundplane 106, and SELS' 204d and 204e are parallel-connected to the groundplane 106. Note, although each configuration of SELS' 204 is shown as open-connected (unterminated), in other aspects both ends of each configuration may be connected to the groundplane 106 or other circuitry (not shown).



FIG. 8 is a schematic block diagram of a sixth variation of the bracket 108 of FIG. 1. In this aspect, the bracket 108 includes a plurality of fixed electrical length sections 300. As shown, two FELS' 300 are series-connected through an intervening SELS 204. Note, although the series of sections is shown as open-connected (unterminated), in other aspects both ends of the bracket may be connected to the groundplane 106 or other circuitry (not shown), or the connections between sections may be terminated in the groundplane 106.



FIG. 9 is a schematic block diagram illustrating a seventh variation of the bracket 108 of FIG. 1. As shown, FELS 300a and 300b are parallel-connected to the groundplane 106 through separate SELS' 204a and 204b, respectively. Alternately, FELS' 300c and 300d are parallel-connected through a single SELS 204c. Note, although each configuration of sections is shown as open-connected (unterminated), in other aspects both ends of each configuration may be connected to the groundplane 106 or other circuitry (not shown).



FIG. 10 is a schematic diagram illustration some combinations of series-connected and parallel-connected FELS' 300.



FIG. 11 is a plan view schematic diagram illustrating a bracket design 1100 where a plurality of fixed electrical length sections form a matrix of adjoining conductive areas 1102. For example, the adjoining conductive areas may part of a wireless device keyboard that is mounted overlying PCB groundplane 106. The spaces, represented with cross-hatched lines, are the individual keypads. In this aspect, the adjoining conductive areas 1102 are the FELS'. The bracket 1100 also includes a plurality of selectable electrical length sections 204 that are used to couple between fixed electrical length sections 1102. A variety of connection configurations are shown, but the examples are not exhaustive of every possible combination. At least one of the selectable electrical length sections 204 is coupled to the groundplane 106. Alternately, a FELS, enabled as a screw or wire (not shown), for example, may connect the bracket 1100 to the groundplane 106.



FIG. 12 is a perspective cutaway view illustrating a bracket housing design 1200. A housing 1202 surrounds the electrical circuit 104, and functions as a bracket element. A third fixed electrical length section 300c is a conductive trace (or conductive paint) formed on the housing 1200, coupled to the groundplane 106 through a SELS 204. As shown, SELS 204 is connected to a first FELS 300a, enabled as a conductive trace of a PCB, a second FELS 300b, enabled as a screw, connects FELS 300a to 300c. In other aspects, the FELS 300b can be a spring-loaded clip, pogo pin, or a conductive pillow (gasket). A variety of other bracket configurations are possible that make use of the housing as a bracket element, as would be understood by those skilled in the art in light of the above-mentioned examples.



FIG. 18 is a plan view drawing of a wireless device display bracket design. In this aspect the electrical circuit is a liquid crystal display (LCD) 1800 or other type of display circuit. The bracket 108 includes a (at least one) selectable electrical length section 204 coupling between fixed electrical length sections 300. A plurality of fixed electrical length sections 300 form perimeter regions around the LCD 1800. The exact shape of the perimeter is determined by using the SELS' 204 to couple or connect FELS' 300. The perimeter need not necessarily be closed. As shown the perimeter has an opening 1804. The opening 1804 placement and electrical length may be tuned used a SELS 204 in response to changing transmission frequencies, for example. Further, the opening 1804 may be formed as a result of not switching a SELS 204. Although the perimeter regions are shown as series-connected, parallel connections are also possible using a SELS 204. Further, a SELS 204 or FELS 300 may be used to connect the bracket 108 to a groundplane, such as a proximate PCB groundplane 106.



FIG. 13 is a perspective drawing illustrating some exemplary FELS variations. The FELS 300 can be a conductive metal member that is soldered or tension mounted to a bracket or groundplane. The metal form can be straight 1300, L-shaped 1302, or O-shaped member 1304. Other shapes, or combinations of shapes are possible. Some shapes are dependent upon the surrounding area available. In addition, the FELS may be a wire 1306, a fastener, such as screw 1308, conductive pillow (gasket) 1312, or a conductive element, such as a conductive trace or paint 1310 formed on a PCB or housing. These are just a few examples of FELS elements. Any element capable of conducting an electrical current is potentially capable of acting as a FELS.



FIG. 14 is a schematic block diagram of the present invention portable wireless telephone communications device with a reconfigurable radiation desensitivity bracket. The device 1400 comprises a telephone transceiver 1402 and an antenna 1404 connected to the transceiver 1402. The portable device 1400 includes an electrical circuit 1406 having a groundplane 1408. A reconfigurable radiation desensitivity bracket 1410 is coupled to the groundplane 1408. As in the more generic wireless device described in FIG. 1, the portable device electrical circuit 1406 may be components mounted on a printed circuit board (PCB), a display, a connector, or a keypad. The details of bracket 1410 are essentially the same as the brackets described in FIGS. 1 through 13 and 18, above, and will not be repeated in the interest of brevity.



FIG. 15 is a schematic block diagram of the present invention wireless communications base station with a reconfigurable radiation desensitivity bracket. The base station 1500 comprises a telephone transceiver 1502 and an antenna 1504 connected to the transceiver 1502. In this case, two antennas marked 1504 are shown. The base station 1500 also includes an electrical circuit 1506 having a groundplane 1508. A reconfigurable radiation desensitivity bracket 1510 is coupled to the groundplane 1508. As in the more generic wireless device described in FIG. 1, the base station electrical circuit 1506 may be components mounted on a printed circuit board (PCB), a display, a connector, or a keypad. The details of bracket 1510 are essentially the same as the brackets described in FIGS. 1 through 13 and 18, above, and will not be repeated in the interest of brevity.


Functional Description


FIGS. 16A and 16B are diagrams illustrating the present invention bracket redistributing radiation-induced current flow in a groundplane. The vertical dimension illustrates current flow (I). The current through an area (unit2) is one possible measure of current distribution, for example, A/in2. However, other measurements of current or current distribution can be used to illustrate the invention. In FIG. 16A, a relatively high current flow in shown in one particular region as a result of a source radiating at 890 MHz. In response to enabling the bracket 108, the current flow is redistributed, as shown in FIG. 16B. The bracket may be considered frequency reconfigurable, as a different electrical length may be used for different radiated frequencies. Alternately, the bracket may be considered space-reconfigurable, as it can be used to redistribute current flow to different regions of the groundplane. For example, the bracket 108 may be tuned to redistribute current (as shown in FIG. 16A) after device is moved near a proximate object, to create the current pattern shown in FIG. 16B.



FIG. 17 is a flowchart illustrating the present invention method for reconfigurable radiation desensitivity in a wireless communications device. Although the method is depicted as a sequence of numbered steps for clarity, no order should be inferred from the numbering unless explicitly stated. It should be understood that some of these steps may be skipped, performed in parallel, or performed without the requirement of maintaining a strict order of sequence. The method starts at Step 1700.


Step 1702 generates a radiated wave at a first frequency. Alternately stated, Step 1702 transmits at a first frequency. Step 1704 in response to generating the radiated wave at the first frequency, creates a maximum current per units square (I/units2) through a minimal area of an electrical circuit groundplane. That is, current flow is induced as a result of the wave radiated in Step 1702. Step 1706 generates a radiated wave (transmits) at a second frequency. Alternately stated, the wireless device changes the frequency of transmission between Steps 1702 and 1706. Step 1708, in response to generating the radiated wave at the second frequency, maintains the maximum I/units2 through the minimal area of the groundplane. Alternately stated, with respect to a groundplane area with a predetermined (minimal) size, radiation-associated current flow is not allowed to exceed a predetermined (maximum) level.


The groundplane may be associated with an electrical circuit such as components mounted on a printed circuit board (PCB), a display, a connector, or a keypad. However, the invention is not limited to any particular type of electrical circuit or groundplane. The choice of the current-related measurement is somewhat arbitrary, and the invention can also be expressed in other units of measurement related to current, energy, or field strength


Typically, maintaining the maximum I/units2 through the minimal area of the groundplane (Step 1708) includes coupling the groundplane to a bracket having a selectable effective electrical length. The coupling mechanism may be transistor coupling, where the transistor acts as a switch, buffer, current amplifier, voltage amplifier, or reactance element. In other aspects, the coupling mechanism is p/n junction coupling through a PIN diode, selectable capacitive coupling through a varactor diode or ferroelectric capacitor, variable gap coupling using a MEMS, or mechanically bridging through a switch or MEMS. The same analysis applies to Step 1704.


In one aspect, Step 1708 (or Step 1704) additionally couples the groundplane to a bracket with a fixed physical length section to provide a combined effective electrical length responsive to the fixed physical length and the selectable effective electrical length. Further, the groundplane may be coupled to a bracket with a plurality of selectable electrical length sections. The plurality of selectable electrical length sections may be connected in a configuration such as groundplane connected, series-connected, parallel-connected, or combinations of the above-mentioned connection configurations. The invention is not limited to any particular connection configuration type.


In another aspect, Step 1708 (Step 1704) couples the groundplane to a bracket with a plurality of fixed physical length sections. The plurality of fixed electrical length sections can be connected to a selectable electrical length section in a configuration such as connected to the groundplane, series-connected, parallel-connected, or combinations of the above-mentioned connection configurations.


A wireless communications device with a reconfigurable radiation desensitivity bracket, and corresponding reconfigurable radiation desensitivity method have been provided. Some examples of specific bracket shapes and schematic arrangements have been presented to clarify the invention. Likewise, some specific physical implementations and uses for the invention have been mentioned. However, the invention is not limited to just these examples. Other variations and embodiments of the invention will occur to those skilled in the art.

Claims
  • 1. A wireless communications device comprising: a wireless telephone transmitter configured to operate at a first frequency and a second frequency;an antenna connected to the transmitter;an electrical circuit having a groundplane; and,a reconfigurable radiation desensitivity bracket coupled to the groundplane and having a selectable effective electrical length responsive to control signals to have a first effective electrical length selected in response to the transmitter operating at the first frequency, and a second effective electrical length, selected in response to the transmitter operating at the second frequency.
  • 2. The device of claim 1 wherein the electrical circuit is selected from the group including components mounted on a printed circuit board (PCB), a display, a connector, and a keypad.
  • 3. The device of claim 1 wherein the selectable electrical length section has a distal end, a proximal end, a control input to accept the control signals.
  • 4. The device of claim 3 wherein the bracket comprises a fixed electrical length section having a distal end, a proximal end, and a fixed physical length, the combination of the selectable electrical length section and the fixed electrical length section providing a combined selectable effective electrical length responsive to the control signal.
  • 5. The device of claim 4 wherein the bracket includes a plurality of fixed electrical length sections.
  • 6. The device of claim 5 wherein the plurality of fixed electrical length sections are connected to a selectable electrical length section in a configuration selected from the group including connected to the groundplane, series-connected, parallel-connected, and combinations of the above-mentioned connection configurations.
  • 7. The device of claim 6 wherein the plurality of fixed electrical length sections form a matrix of adjoining conductive areas; wherein a plurality of selectable electrical length sections couple between fixed electrical length sections; and,wherein at least one of the plurality of selectable electrical length sections is coupled to the groundplane.
  • 8. The device of claim 4 wherein the fixed electrical length section is an element selected from the group including a wire, conductive paint, conductive trace, conductive pillow, fastener, and a member formed straight, L-shaped, O-shaped, and combinations of the above-mentioned forms.
  • 9. The device of claim 4 further comprising: a housing surrounding the electrical circuit; and,wherein the fixed electrical length section is a conductive element formed on the housing and coupled to the groundplane.
  • 10. The device of claim 4 wherein the fixed electrical length section is a conductive trace formed on the electrical circuit.
  • 11. The device of claim 4 wherein the electrical circuit is a liquid crystal display (LCD); wherein the bracket includes: a selectable electrical length section coupling between fixed electrical length sections; and,a plurality of fixed electrical length sections forming perimeter regions around the LCD.
  • 12. The device of claim 3 wherein the bracket includes a plurality of selectable electrical length sections.
  • 13. The device of claim 12 wherein the plurality of selectable electrical length sections are connected in a configuration selected from the group including connected to the groundplane, series-connected, parallel-connected, and combinations of the above-mentioned connection configurations.
  • 14. The device of claim 3 wherein the selectable electrical length section is selected from the group including a FET, PIN diode, ferroelectric capacitor, varactor diode, and microelectromechanical system (MEMS) switch.
  • 15. The device of claim 3 further comprising: a desensitivity control circuit having an input to accept frequency selection commands and an output connected to the selectable effective length sections, supplying control signals in response to the frequency selection commands.
  • 16. The device of claim 1 wherein the transmitter is a wireless telephone transmitter.
  • 17. A portable wireless telephone communications device with a reconfigurable radiation desensitivity bracket, the device comprising: a telephone transceiver;an antenna connected to the transceiver;an electrical circuit having a groundplane; and,a reconfigurable radiation desensitivity bracket coupled to the groundplane and responsive to control signals to vary current flow through the groundplane in accordance with a frequency of operation of the telephone transceiver.
  • 18. The portable device of claim 17 wherein the electrical circuit is selected from the group including components mounted on a printed circuit board (PCB), a display, a connector, and a keypad.
  • 19. The portable device of claim 17 wherein the bracket includes a selectable electrical length section having a distal end, a proximal end, a control input to accept control signals, and a selectable effective electrical length responsive to the control signals.
  • 20. The portable device of claim 19 wherein the bracket further includes a fixed electrical length section having a distal end, a proximal end, and a fixed physical length; and, wherein the combination of the selectable electrical length section and the fixed electrical length section provides a combined selectable effective electrical length responsive to the control signal.
  • 21. A wireless communications base station with a reconfigurable radiation desensitivity bracket, the base station comprising: a base station telephone transceiver;an antenna connected to the transceiver;an electrical circuit having a groundplane; and,
  • 22. The base station of claim 21 wherein the bracket includes a selectable electrical length section having a distal end, a proximal end, a control input to accept control signals, and a selectable effective electrical length responsive to the control signals.
  • 23. The base station of claim 22 wherein the bracket further includes a fixed electrical length section having a distal end, a proximal end, and a fixed physical length; and, wherein the combination of the selectable electrical length section and the fixed electrical length section provides a combined selectable effective electrical length responsive to the control signal.
  • 24. A wireless communication device comprising: a wireless transceiver;an antenna connected to the transceiver and comprising a groundplane; anda reconfigurable radiation desensitivity bracket coupled to the groundplane and responsive to control signals to vary current flow through the groundplane in accordance with a frequency of operation of the wireless transceiver.
  • 25. The wireless communication device of claim 24 wherein the bracket has a selectable effective electrical length responsive to the control signals to have a first effective electrical length in response to the transceiver operating at a first frequency and a second effective electrical length, selected in response to the transceiver operating at a second frequency.
  • 26. A wireless communications device comprising: a transmitter;an antenna connected to the transmitter;a liquid crystal display (LCD) having a groundplane; anda reconfigurable radiation bracket coupled to the groundplane and comprising: a plurality of fixed electrical length sections forming perimeter regions around the LCD; anda selectable electrical length section having a selectable effective electrical length responsive to a control signal, a distal end, a proximal end, and a control input to accept the control signal, the combination of the selectable electrical length section and the fixed electrical length sections providing a combined selectable effective electrical length responsive to the control signals.
RELATED APPLICATIONS

This application is a continuation-in-part application of U.S. application Ser. No. 10/775,722, filed Feb. 9, 2004, now U.S. Pat. No. 6,937,195 by Jordi Fabrega-Sanchez, Stanley S. Toncich and Allen Tran, which is hereby incorporated by reference. U.S. application Ser. No. 10/775,722 is a continuation-in-part application of U.S. application Ser. No. 10/120,603, filed Apr. 9, 2002, now U.S. Pat. No. 6,885,341 by Jordi Fabrega-Sanchez, Stanley S. Toncich and Allen Tran, which is hereby incorporated by reference, which claims the benefit of U.S. Provisional Application 60/283,093, filed Apr. 11, 2001, which is hereby incorporated by reference. In addition, this application relates to the following U.S. applications and patents, which are hereby incorporated by reference: “Reconfigurable Radiation Desensitivity Bracket Systems and Methods”, filed on the same day and having the same inventors as the present application; U.S. Pat. No. 6,690,176, issued Feb. 10, 2004, by Stanley S. Toncich, entitled “Low Loss Tunable Ferro-Electric Device and Method of Characterization”; U.S. Pat. No. 6,765,540 B2, issued Jul. 20, 2004, by Stanley S. Toncich, entitled “Tunable Antenna Matching Circuit”; application Ser. No. 09/927,136, filed Aug. 10, 2001, by Stanley S. Toncich, entitled “Tunable Matching Circuit”; application Ser. No. 10/076,171, filed Feb. 12, 2002, by Stanley S. Toncich, entitled “Antenna Interface Unit”; and application Ser. No. 10/117,628, filed Apr. 4, 2002, by Stanley S. Toncich and Allen Tran, entitled “Ferroelectric Antenna and Method for Tuning Same”.

US Referenced Citations (168)
Number Name Date Kind
3239838 Kelleher Mar 1966 A
3413543 Schubring et al. Nov 1968 A
3573628 Cramer et al. Apr 1971 A
3676803 Simmons Jul 1972 A
3678305 Paige Jul 1972 A
3680135 Boyer Jul 1972 A
3737814 Pond Jun 1973 A
3739299 Adler Jun 1973 A
3836874 Maeda et al. Sep 1974 A
3918012 Peuzin Nov 1975 A
4122400 Medendorp et al. Oct 1978 A
4236125 Bernard et al. Nov 1980 A
4475108 Moser Oct 1984 A
4484157 Helle et al. Nov 1984 A
4494081 Lea et al. Jan 1985 A
4525720 Corzine et al. Jun 1985 A
4626800 Murakami et al. Dec 1986 A
4733328 Blazej Mar 1988 A
4736169 Weaver et al. Apr 1988 A
4737797 Siwiak et al. Apr 1988 A
4746925 Toriyama May 1988 A
4792939 Hikita et al. Dec 1988 A
4799066 Deacon Jan 1989 A
4835499 Pickett May 1989 A
4835540 Haruyama et al. May 1989 A
4847626 Kahler et al. Jul 1989 A
4876552 Zakman Oct 1989 A
4908853 Matsumoto Mar 1990 A
4975604 Barta Dec 1990 A
5166857 Avanic et al. Nov 1992 A
5173709 Lauro et al. Dec 1992 A
5212463 Babbitt et al. May 1993 A
5216392 Fraser Jun 1993 A
5227748 Sroka Jul 1993 A
5231407 McGirr et al. Jul 1993 A
5293408 Takahashi et al. Mar 1994 A
5307033 Koscica et al. Apr 1994 A
5325099 Nemit et al. Jun 1994 A
5388021 Stahl Feb 1995 A
5406163 Carson et al. Apr 1995 A
5416803 Janer May 1995 A
5427988 Sengupta et al. Jun 1995 A
5450092 Das Sep 1995 A
5451915 Katzin et al. Sep 1995 A
5459123 Das Oct 1995 A
5472935 Yandrofski et al. Dec 1995 A
5479139 Koscica et al. Dec 1995 A
5495215 Newell et al. Feb 1996 A
5496795 Das Mar 1996 A
5496796 Das Mar 1996 A
5502422 Newell et al. Mar 1996 A
5525942 Horii et al. Jun 1996 A
5557286 Varadan et al. Sep 1996 A
5561307 Mihara et al. Oct 1996 A
5561407 Koscica et al. Oct 1996 A
5564086 Cygan et al. Oct 1996 A
5574410 Collins et al. Nov 1996 A
5577025 Skinner Nov 1996 A
5583524 Milroy Dec 1996 A
5589845 Yandrofski et al. Dec 1996 A
5600279 Mori Feb 1997 A
5617104 Das Apr 1997 A
5640042 Koscica et al. Jun 1997 A
5649306 Vanatta et al. Jul 1997 A
5652599 Wallace et al. Jul 1997 A
5673188 Lusher et al. Sep 1997 A
5701595 Green, Jr. Dec 1997 A
5721194 Yandrofski et al. Feb 1998 A
5729239 Rao Mar 1998 A
5777524 Wojewoda et al. Jul 1998 A
5777839 Sameshima et al. Jul 1998 A
5778308 Sroka et al. Jul 1998 A
5830591 Sengupta et al. Nov 1998 A
5834975 Bartlett et al. Nov 1998 A
5864932 Evans et al. Feb 1999 A
5870670 Ripley Feb 1999 A
5880921 Tham et al. Mar 1999 A
5889852 Rosecrans et al. Mar 1999 A
5892486 Cook et al. Apr 1999 A
5908811 Das Jun 1999 A
5910994 Lane et al. Jun 1999 A
5945887 Makino et al. Aug 1999 A
5965494 Terashima et al. Oct 1999 A
5973567 Heal et al. Oct 1999 A
5973568 Shapiro Oct 1999 A
5977917 Hirose Nov 1999 A
5986515 Sakurai Nov 1999 A
5987314 Salto Nov 1999 A
5990766 Zhan Nov 1999 A
6008659 Traynor Dec 1999 A
6018282 Tsuda Jan 2000 A
6020787 Kim et al. Feb 2000 A
6026311 Willemsen Cortes et al. Feb 2000 A
6028561 Takei Feb 2000 A
6049726 Gruenwald et al. Apr 2000 A
6052036 Enstrom et al. Apr 2000 A
6054908 Jackson Apr 2000 A
6084951 Smith et al. Jul 2000 A
6094588 Adam Jul 2000 A
6097263 Mueller et al. Aug 2000 A
6101102 Brand et al. Aug 2000 A
6108191 Bruchhaus et al. Aug 2000 A
6160524 Wilber Dec 2000 A
6181777 Kiko Jan 2001 B1
6198441 Okabe Mar 2001 B1
6216020 Findikoglu Apr 2001 B1
6242843 Pohjonen et al. Jun 2001 B1
6272336 Appel et al. Aug 2001 B1
6278383 Endo et al. Aug 2001 B1
6281023 Eastep et al. Aug 2001 B2
6281534 Arita et al. Aug 2001 B1
6285337 West et al. Sep 2001 B1
6292143 Romanofsky Sep 2001 B1
6294964 Satoh Sep 2001 B1
6308051 Atokawa Oct 2001 B1
6317083 Johnson et al. Nov 2001 B1
6327463 Welland Dec 2001 B1
6329959 Varadan et al. Dec 2001 B1
6333719 Varadan Dec 2001 B1
6335710 Falk et al. Jan 2002 B1
6344823 Deng Feb 2002 B1
6359444 Grimes Mar 2002 B1
6362690 Tichauer Mar 2002 B1
6362784 Kane et al. Mar 2002 B1
6362789 Trumbull et al. Mar 2002 B1
6384785 Kamogawa et al. May 2002 B1
6404304 Kwon et al. Jun 2002 B1
6421016 Philips et al. Jul 2002 B1
6456236 Hauck et al. Sep 2002 B1
6462628 Kondo et al. Oct 2002 B2
6489860 Ohashi Dec 2002 B1
6503786 Klodzinski Jan 2003 B2
6518850 Falk et al. Feb 2003 B1
6518920 Proctor, Jr. et al. Feb 2003 B2
6522220 Yamada et al. Feb 2003 B2
6525630 Zhu et al. Feb 2003 B1
6525691 Varadan et al. Feb 2003 B2
6531936 Chiu et al. Mar 2003 B1
6559737 Nagra et al. May 2003 B1
6571110 Patton et al. May 2003 B1
6600456 Gothard et al. Jul 2003 B2
6653977 Okabe et al. Nov 2003 B1
6667723 Forrester Dec 2003 B2
6686817 Zhu et al. Feb 2004 B2
6721293 Komulainen et al. Apr 2004 B1
6727535 Sengupta et al. Apr 2004 B1
6819203 Taniguchi Nov 2004 B2
6842086 Zennamo et al. Jan 2005 B1
6873294 Anderson et al. May 2005 B1
6898450 Eden et al. May 2005 B2
6985113 Nishimura et al. Jan 2006 B2
6987486 Kurjenheimo et al. Jan 2006 B2
20010026243 Koitsalu et al. Oct 2001 A1
20010043159 Masuda et al. Nov 2001 A1
20020049064 Banno Apr 2002 A1
20020149526 Tran et al. Oct 2002 A1
20020149535 Toncich Oct 2002 A1
20020175878 Toncich Nov 2002 A1
20030062971 Toncich Apr 2003 A1
20030134665 Kato et al. Jul 2003 A1
20030169206 Egawa Sep 2003 A1
20040087280 Watanabe et al. May 2004 A1
20040162047 Kasahara et al. Aug 2004 A1
20040196121 Toncich Oct 2004 A1
20040204145 Nagatomo Oct 2004 A1
20040207722 Koyama et al. Oct 2004 A1
20040263411 Fabrega-Sanchez et al. Dec 2004 A1
20050007291 Fabrega-Sanchez et al. Jan 2005 A1
Foreign Referenced Citations (35)
Number Date Country
40 36 866 Jul 1991 DE
100 24 483 Nov 2001 DE
101 37 753 Feb 2003 DE
0 125 586 Nov 1984 EP
0 346 089 Dec 1989 EP
0 473 373 Mar 1992 EP
0 531 125 Mar 1993 EP
0 631 399 Dec 1994 EP
0 637 131 Feb 1995 EP
0 638 953 Feb 1995 EP
0 680 108 Nov 1995 EP
0 795 922 Sep 1997 EP
0 843 374 May 1998 EP
0 854 567 Jul 1998 EP
0 872 953 Oct 1998 EP
0 881 700 Dec 1998 EP
0 892 459 Jan 1999 EP
0 909 024 Apr 1999 EP
1 043 741 Oct 2000 EP
1 058 333 Dec 2000 EP
1 248 317 Oct 2002 EP
2 240 227 Jul 1991 GB
63 128618 Jun 1988 JP
05182857 Jul 1993 JP
290500-2001133839 Jul 2001 JP
WO 8203510 Oct 1982 WO
WO 9413028 Jun 1994 WO
WO 9427376 Nov 1994 WO
WO 0028613 May 2000 WO
WO 0035042 Jun 2000 WO
WO 0062367 Oct 2000 WO
WO 0079645 Dec 2000 WO
WO 0079648 Dec 2000 WO
WO 02084798 Oct 2002 WO
WO 03058759 Jul 2003 WO
Related Publications (1)
Number Date Country
20050083234 A1 Apr 2005 US
Provisional Applications (1)
Number Date Country
60283093 Apr 2001 US
Continuation in Parts (2)
Number Date Country
Parent 10775722 Feb 2004 US
Child 10940702 US
Parent 10120603 Apr 2002 US
Child 10775722 US