The present invention relates to a switch for high frequency signals, such as signals of frequencies over 85 GHz.
In recent years, in communications electronics, a shift towards increasingly high frequencies has been ongoing. In order to perform measurements in these frequency ranges, the requirements regarding hardware are continually increasing in complexity and cost. More specifically, this shift to higher frequencies has generated needs for enhanced frequency behavior, while commercial aspects increasingly require low costs and decreasing physical footprints. For example, U.S. Pat. No. 7,489,179 B2 shows a step attenuator comprising high frequency switches. The technology described in this patent, however, does not allow for sufficiently high frequencies.
Accordingly, there is a need for a switch configured to switch between different high frequency signals or signal destinations, and that is capable of handling very high frequencies, and at the same time only requiring a low cost of construction and having a small physical footprint.
Embodiments of the present invention advantageously address the foregoing requirements and needs, as well as others, by providing a switch configured to switch between different high frequency signals or signal destinations, and that is capable of handling very high frequencies, and at the same time only requiring a low cost of construction and having a small physical footprint.
In accordance with example embodiments of the present invention, a high frequency switch is provided. The high frequency switch comprises a first high frequency connector, comprising a first inner conductor, integrally formed with a first strip conductor. The high frequency switch further comprises a second strip conductor arranged orthogonally in a first plane relative to the first strip conductor, and a third strip conductor arranged orthogonally in the first plane relative to the first strip conductor. The high frequency switch further comprises a first switching conductor having an orthogonally angled shape relative to the first plane, and a second switching conductor having an orthogonally angled shape relative to the first plane.
According to a further embodiment, the high frequency switch further comprises a switching actuator, mechanically connected to the first switching conductor and to the second switching conductor, which is configured to move vertically relative to the first plane between a first position and a second position. It is thereby possible to switch signals between the three strip conductors in a high frequency behavior, and with a small physical footprint and at a low cost of manufacture.
According to a first such embodiment, the switching actuator, the first switching conductor and the second switching conductor are configured so that in the first position, the first strip conductor is in contact with the first switching conductor, the second strip conductor is in contact with the first switching conductor, and the second switching conductor is not in contact with the first strip conductor, the second strip conductor and the third strip conductor. Thereby, a high isolation of the non-switched strip conductor is achieved.
According to a second such embodiment, the switching actuator, the first switching conductor and the second switching conductor are configured so that in the second position, the first strip conductor is in contact with the second switching conductor, the second strip conductor is in contact with the second switching conductor and the first switching conductor is not in contact with the first strip conductor, the second strip conductor and the third strip conductor. Thereby, a high isolation of the non-switched strip conductor is also achieved.
According to a third such embodiment, the high frequency connector comprises a first port-support, holding the first inner conductor and the first strip conductor. A very simple construction of the first high frequency connector is thereby achieved.
According to a fourth such embodiment, the switch additionally comprises a second high frequency connector, comprising a second inner conductor, integrally formed with the second strip conductor, and a third high frequency connector, comprising a third inner conductor, integrally formed with the third strip conductor. A switching between signals on the three high frequency connectors is thereby possible, which allows for a very simple to construct switch with three coaxial ports.
According to a further embodiment, the first high frequency connector comprises a first port support, holding the first inner conductor and the first strip conductor. Additionally or alternatively, the second high frequency connector comprises a second port support, holding the inner conductor and the second strip conductor. Additionally or alternatively, the third high frequency connector comprises a third port support, holding the third inner conductor and the third strip conductor. A further simplified to construct switch can thereby be achieved.
According to a further embodiment, the second high frequency connector and the third high frequency connector are each orthogonally arranged relative to the first high frequency connector in the first plane. This allows for a very high isolation between the switched and the non-switched strip conductor, since the electromagnetic fields are also arranged orthogonally.
By way of example, the first strip conductor and/or the second strip conductor and/or the third strip conductor have a thickness of 0.1-0.5 mm, and more specifically can have a thickness of 0.25 mm. By way of further example, the first strip conductor and/or the second strip conductor and/or the third strip conductor have a width of 0.25 mm-2.0 mm, and more specifically can have a width of 0.5 mm. This allows for a very small physical footprint of the resulting switch, while still functionally achieving extremely high frequencies.
According to a further embodiment, the high frequency switch comprises a housing in a sandwich construction, which further facilitates simplicity in the construction of the switch.
According to a further embodiment, the high frequency switch comprises a high frequency baseplate, comprising a strip conductor channel, connected to ground. The strip conductor channel at least partially encloses the first strip conductor, the second strip conductor and the third strip conductor. The first strip conductor, the second strip conductor and the third strip conductor are separated from the strip conductor channel by an electrically non-conductive gap in the first plane. The electromagnetic field thereby exists between the edge of the respective strip conductor and the electrically conductive inner surface of the strip conductor channel. This allows for further decreases in the physical footprint of the resulting switch.
By way of example, the gap has a width of 0.1 mm-0.5 mm, and more specifically may have a gap width of 0.25 mm, which facilitates a very small construction of the switch.
According to a further embodiment, the high frequency baseplate comprises a first high frequency wall blocking the strip conductor channel between the second strip conductor and the second switching conductor. Alternatively or additionally, the high frequency baseplate comprises a second high frequency wall, blocking the strip conductor channel between the third strip conductor and the first switching conductor. By use of these high frequency walls, it is possible to further increase the isolation between the two strip conductor branches formed by the second strip conductor and the third strip conductor.
According to a further embodiment, the first strip conductor and/or the second strip conductor and/or the third strip conductor are held in place by axially symmetric non-conductive support elements, within the strip conductor channel. This allows for a very high precision positioning of the strip conductors and thereby allows a very beneficial high frequency behavior of the switch.
According to a further embodiment, the high frequency switch comprises a lower housing and an upper housing. The lower and the upper housing cover the high frequency baseplate and the strip conductor channel, are electrically conductive, and are electrically isolated from the first strip conductor, the second strip conductor, and the third strip conductor. This allows for very beneficial high frequency behavior.
According to a further embodiment, the switching actuator, the first switching conductor and the second switching conductor are configured so that in the first position, the second switching conductor is in contact to the upper housing and so that in the second position, the first switching conductor is in contact to the lower housing. Thereby, contact to a ground plane is achieved. This allows for defined voltage conditions and thereby prevents resonances of the non-switching switching conductor.
Still other aspects, features, and advantages of the present invention are readily apparent from the following detailed description, simply by illustrating a number of particular embodiments and implementations, including the best mode contemplated for carrying out the present invention. The present invention is also capable of other and different embodiments, and its several details can be modified in various obvious respects, all without departing from the spirit and scope of the present invention. Accordingly, the drawing and description are to be regarded as illustrative in nature, and not as restrictive.
Embodiments of the present invention are illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings, in which like reference numerals refer to similar elements, and in which:
Approaches for a switch configured to switch between different high frequency signals or signal destinations, and that is capable of handling very high frequencies, and at the same time only requiring a low cost of construction and having a small physical footprint, are described. It is apparent, however, that the invention may be practiced without these specific details or with an equivalent arrangement. In other instances, well-known structures and devices are shown in block diagram form in order to avoid unnecessarily obscuring the invention.
First, the general construction of a multi-stage step attenuator is described with reference to
Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. However, the following embodiments of the present invention may be variously modified and the range of the present invention is not limited by the following embodiments.
Further details of the individual elements will be given in the further figures.
The strip conductors 31, 32 are held in place by axially symmetric non-conductive support elements 33.
The strip conductor channel 35 has a conductive surface. By way of example, the strip conductor channel 35 is machined into the baseplate 3, which is formed from solid metal. Since the support elements 33 hold the strip conductors 31, 32 with a gap towards the strip conductor channel 35, there is no conductive connection between the strip conductors 31, 32 and the strip conductor channel 35. Also, there is no conductive connection between the electrical elements 34 and the strip conductor channel. Further, the components are configured to exhibit a good thermal coupling between the electrical elements 34 and the strip conductor channel, and therefore the baseplate 3, which achieves dissipation of the signal power.
A first strip conductor 36 forms an input of the switch. The first strip conductor 36 can be connected to the strip conductor 32, which connects the electrical element 34 and alternatively to the strip conductor 31, which forms the through connection as explained earlier.
The switch comprises an upper connecting rod 45, connected to a first switching conductor 46 and a lower connecting rod 21, connected to a second switching conductor 26. The connecting rods 45, 21 are connected to one of the actuators 6a-6d and are moved simultaneously.
The switches can be positioned in a first position and in a second position. In the first position shown here, the switching conductor 46 is not in contact with the first strip conductor 36 and the second strip conductor 32. The switching conductor 46 instead is contact with a ground plane, for example the upper housing or the high frequency sealing sheet 22 arranged between the upper housing and the baseplate 3. At the same time, the switching conductors 26 is in contact to the first strip conductor 36 and the third strip conductor 31. The further switch switches in a similar manner. This means that either the second strip conductor 32 or the third strip conductor 31 is connected with the input and output of the respective attenuation stage.
By way of example, the switching conductors 26, 46 are orthogonally shaped in the plane of the strip conductors, and the first strip conductor 36 is arranged orthogonally relative to the second strip conductor 32 and the third strip conductor 31. This achieves an advantageous high frequency behavior, since a high frequency coupling to the presently non-switched path is effectively prevented due to the orthogonal nature of the electromagnetic field.
In the present switching position, the switching conductor 46 is in contact with the first strip conductor 36 and the second strip conductor 32. At the same time, the switching conductor 26 is in contact to the ground plane formed by the high frequency seal 22. In the other switching position, the switching conductor 26 is in contact with the first strip conductor 36 and the third strip conductor 31. At this time, the switching conductor 46 is in contact to the ground formed by the high frequency seal 41.
The switching conductor 46 is connected to the connecting rod 45. The switching conductor 46 in this picture is not in contact with the first strip conductor 36 and the second strip conductor 32. Instead, the switching conductor 26 is in contact with the first strip conductor 36 and the third strip conductor 31. This is though not easily visible in this picture.
Further, the baseplate 3 has a strip conductor channel wall 37 arranged at the bend of the perpendicular shaped switching conductor 46, separating the switching conductor 46 from the third strip conductor 31. For example, an RF coupling of a signal between the third strip conductor and the switching conductor 46 is thereby prevented. A similar strip conductor channel wall 38 is arranged between the second strip conductor 32 and the switching conductor 26. This can readily be seen in
Moreover, the switching conductor 26, 46 can optionally comprise a flattened corner 261 in order to enhance the high frequency behavior.
Furthermore, optionally, the switching conductor 26, 46 can comprise slits 263 in its respective distal ends. These slits are useful for increasing the elasticity of the respective tips of the switching conductor 26, 46, thereby decreasing accuracy requirements regarding the exact positioning of the strip conductors 31, 32, 36.
The first high frequency connector 5a comprises a first inner conductor 52 integrally formed with a first strip conductor 36. The second high frequency connector 321 comprises an inner conductor 320, integrally formed with a second strip conductor 32. The third high frequency connector 311 comprises a third inner conductor 310 integrally formed with a third strip conductor 31.
By way of example, the first strip conductor 36 is arranged orthogonally relative to the second strip conductor 32 in the first plane. Within the same first plane, the first strip conductor 36 is arranged orthogonally to the third strip conductor 31.
By way of further example, the inner conductors 52, 320, 310 of the high frequency connectors 5a, 321, 311 are each arranged in line with the respectively integrally formed strip conductor 36, 32, 31. Therefore, also the high frequency connectors 5a, 321, 311 are arranged in a similar configuration to the respective strip conductor 36, 32, 31. This means that the first high frequency connector 5a is arranged orthogonally to the second high frequency connector 321. Also the first high frequency connector 5a is arranged orthogonally to the third high frequency connector 311.
According to a further embodiment, the switch 100 further comprises a first switching conductor 26 connected to a connecting rod 21 and a second switching conductor 46 connected to a connecting rod 45. The connecting rods 21, 45 are connected to a non-depicted switching actuator, which moves the connecting rods 21, 45 simultaneously and thereby also moves the switching conductors 26, 46 simultaneously. The switching actuator is configured to move the switching conductors 26, 46 between a first position and a second position. In the first position, the first switching conductor 26 is in contact to the first strip conductor 36 and the second strip conductor 32, while the second switching conductor 46 is not in contact to any of the strip conductors 36, 32, 31 but instead to a ground plane. In the second position, the second switching conductor 46 is in contact to the first strip conductor 36 and the third strip conductor 31, while the first switching conductor 26 is not in contact to any of the strip conductors 36, 32, 31 but instead to a ground plane.
This means that the first switching conductor 26 in
Here, the high frequency connector 5a comprises an outer conductor 51 and an inner conductor 52. In this example, the conductors 51, 52 form a coaxial connector. Within the high frequency connector 5a, a port support 53 is arranged, which holds the inner conductor 52 within the outer conductor 51 in a non-conductive manner. Since the inner conductor 52 is integrally formed with the first strip conductor 36, the port support 53 also holds the first strip conductor 36 in position. On the right side of
The actuator 6a comprises a ridge 68 and is held in place by a securing spring 67, which locks in the ridge 68 and holds the actuator in its place in the respective hole of the upper housing, lower housing and baseplate.
Moreover, the actuator 6a comprises an actuator-element 63a, 63b, which is moved up and down by the actuator 6a between a first position and a second position. The actuator-element 63a is connected to an elastic element 61a on the top side of the actuator 6a and to a second elastic element 61b on the bottom side of the actuator 6a. The actuator-element 63a moves a first side of the elastic elements 61a, 61b, which corresponds to the central part of the respective elastic elements 61a, 61b. In this example, the elastic elements 61a, 61b are diaphragm springs. They comprise a number of slits 62a, 62b, by which the elastic characteristic of the diaphragm springs can be tuned.
Connected to a second side of the elastic elements 61a, 61b are shafts 64a, 64b, which are connected to the connecting rods 21, 45, which in turn are connected to the switching conductors 26, 46. The shafts 64a, 64b are moreover connected to springs 66a, 66b, which on their respective other side are in contact with the outer side of the baseplate, exerting an elastic force, forcing the respectively connected switching conductors 26, 46 away from each other.
The shafts 64a, 64b are moreover supplied with loops 65a, 65b, which are used for preventing the shafts 64a, 64b from rotating.
The actuator 6a is provided with shafts 64a, 64b, connecting rods 21, 45 and switching conductors 26, 46 on a left side and on a right side and therefore are symmetrical. They are adapted to move the switches simultaneously, as also depicted in
The actuator 6a is supplied with a switching current through a cable 61.
Arranged within the housing 69 and fixed to the housing is a permanent magnet 67. Moreover an electromagnet 70 is arranged fixed to the housing 69. The core 68 along with the actuator element 63a, 63b is therefore movable relative to the permanent magnet 67 and the electromagnet 70.
The permanent magnet 67 makes sure, that there is always a magnetic force pulling the actuator-element 63a, 63b either towards a first switching position or a second switching position. This means that the core 68 is either in contact with an upper side of the housing 69 or a lower side of the housing 69. The magnetic force is in equilibrium in a central position, but this position is not stable. Therefore, the actuator is bi-stable in the two switching positions. By running a switching current through the electromagnet 70, the magnetic force of the permanent magnet 67 is overpowered, thereby allowing a switching between the two stable states.
In
The invention is not limited to the examples. The invention discussed above can be applied to many different types of switches. Further, the type of actuator is not to be understood as limiting. The characteristics of the example embodiments can be used in any combination.
Although the present invention and its advantages have been described in detail, it should be understood, that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims.
The examples shown in
While various embodiments of the present invention have been described above, it should be understood that they have been presented by way of example only, and not for limitation. Numerous changes to the disclosed embodiments can be made in accordance with the disclosure herein without departing from the spirit or scope of the invention. Thus, the breadth and scope of the present invention should not be limited by any of the above-described embodiments. Rather, the scope of the invention should be defined in accordance with the following claims and their equivalents.
Although the invention has been illustrated and described with respect to one or more implementations, equivalent alterations and modifications will occur to others skilled in the art upon the reading and understanding of this specification and the annexed drawings. In addition, while a particular feature of the invention may have been disclosed with respect to only one of several implementations, such feature may be combined with one or more other features of the other implementations as may be desired and advantageous for any given or particular application.
This application claims the benefit of the earlier filing date under 35 U.S.C. § 119(e) from U.S. Provisional Application Ser. No. 62/424,121 (filed 2016 Nov. 18), which is incorporated herein by reference in its entirety.
Number | Date | Country | |
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62424121 | Nov 2016 | US |