Patent Grant
10522888
This application is a U.S. National Stage entry of PCT Application No: PCT/EP2015/067815 filed Aug. 3, 2015, the contents of which are incorporated herein by reference.
This application relates to a microwave branching switch for selectively interconnecting terminals of a plurality of microwave transmission lines, comprising at least a first microwave transmission line with a first terminal, a second microwave transmission line with a second terminal, a third microwave transmission line with a third terminal and a fourth microwave transmission line with a fourth terminal; a housing in which the terminals of the plurality of microwave transmission lines are arranged; and a switching portion with at least a first junction portion for selectively interconnecting terminals of the plurality of microwave transmission lines by selectively interconnecting the respective microwave transmission lines, wherein the switching portion is switchable between at least a first position and a second position.
Waveguide switches are key hardware used for redundancy switching and signal routing, thanks to their outstanding reliability and very high power handling capacity.
U.S. Pat. No. 2,814,782 describes a waveguide switch comprising first and second rectangular waveguides joined to form a first double mitered ninety degree E-plane bend, the mean distance between miters being approximately equal to one quarter of a guide wavelength, a third rectangular waveguide collinear with said second waveguide and extending in the opposite direction from said bend, means for rotating the outer section of said bend about its midpoint whereby when rotated through ninety degrees, a second bend comprising said first and third waveguides and said section is formed, and dielectric filled slots one quarter wavelength deep formed in opposite edges of said outer section.
U.S. Pat. No. 4,806,887 describes a waveguide R-switch having transformers in one or more of its three waveguide paths. The presence of the transformers allows the R-switch to be constructed of a smaller size than previous R-switches with curved outer paths.
U.S. Pat. No. 6,667,671 B1 describes a waveguide switch having a stator and an electrically conducting movable element, the stator having waveguide paths between waveguide terminal pairs, each path being switchable to conducting or nonconducting with the help of the movable element for high-frequency waves. The movable element is designed as a septum in a gap in the stator and extends in the waveguide path, which is switched to nonconducting, in parallel to its E plane. This divides the waveguide path into two partial waveguides, which run in parallel with one another and, in comparison with the switched-to-conducting state of the waveguide path, have smaller cut-off wavelengths.
U.S. Pat. No. 4,242,652 describes a waveguide switch having four RF ports in coplanar relationship and incorporating four waveguide transmission lines in a single rotating mechanism on two levels, the rotating mechanism being driven by an electromagnetic stepper motor or the like.
U.S. Pat. No. 4,908,589 describes a dielectrically loaded waveguide switch including first and second dielectrically loaded waveguides selectively connected by a switch. The switch includes a third dielectrically loaded waveguide mounted for communication with said first and second waveguides upon switch actuation.
Switches 2 are frequently applied in multiplexer configurations for changing the routing of the input signal, as is illustrated in
By switching all of the switches 2a-2c from a first state (not shown) of the multiplexer 4 to a second state of the multiplexer 4 (as shown in
In the examples shown in
Thus, there is a need for a building block allowing for an increased operational flexibility of switchable electronic circuits. Further, there is a need for a building block allowing for a decreased complexity of switchable electronic circuits.
In view of these needs, the present document proposes a microwave branching switch for selectively interconnecting terminals of a plurality of microwave transmission lines having the features of claim 1. The dependent claims refer to preferred embodiments of the invention.
An aspect of the disclosure relates to a microwave branching switch for selectively interconnecting terminals of a plurality of microwave transmission lines, comprising at least a first microwave transmission line with a first terminal, a second microwave transmission line with a second terminal, a third microwave transmission line with a third terminal and a fourth microwave transmission line with a fourth terminal; a housing in which the terminals of the plurality of microwave transmission lines are arranged; a switching portion with at least a first junction portion for selectively interconnecting terminals of the plurality of microwave transmission lines by selectively interconnecting the respective microwave transmission lines, wherein the switching portion is switchable between at least a first position and a second position; wherein the switching portion with at least the first junction portion is dimensioned and positioned inside the housing in dependence of an arrangement of the plurality of microwave transmission lines such that the first junction portion interconnects a first group of terminals of the plurality of microwave transmission lines when the switching portion is in the first position and interconnects a second group of terminals of the plurality of microwave transmission lines when the switching portion is in the second position, wherein the first group of terminals and the second group of terminals differ in at least one terminal of the plurality of microwave transmission lines and the first group of terminals and/or the second group of terminals comprise the first terminal, the third terminal and the fourth terminal.
Simply put, there exists at least one position of the switching portion for which three or more terminals are interconnected such that microwaves entering the microwave branching switch through one terminal leave the microwave branching switch through two other terminals or that microwaves entering the microwave branching switch through two terminals at the same time leave the microwave branching switch through one other terminal. Microwaves are electromagnetic waves with frequencies ranging between 300 MHz and 300 GHz.
The second terminal may be disconnected from the first junction portion when the switching portion is in the first position; and either the first terminal or the third terminal or the fourth terminal may be disconnected from the first junction portion when the switching portion is in the second position.
Thus, it is possible to use the microwave branching switch not only to transmit and route microwave signals but also to selectively block microwave signals within a circuit configuration.
The terminal disconnected from the first junction portion may be connected to an impedance, a load or a short circuit.
Thereby the disconnected terminal and the corresponding microwave transmission line are effectively isolated from the other terminals and microwave transmission lines. The impedance, load or short circuit may be a part of the switching portion. In case this part is partly filled with an absorbing material, it may act as a load (i.e. a matched termination).
The first junction portion may be T-shaped or Y-shaped.
If exactly three terminals are to be switchably connected, T- or Y-shaped junction portions facilitate the manufacture of a simply structured switch with short transmission paths.
The plurality of microwave transmission lines may be a plurality of hollow waveguides or a plurality of coaxial lines.
Hollow waveguides may be formed as straight and rigid metal tubes with a rectangular or circular cross section. On the other hand, a coaxial line comprises an outer conductor and an inner conductor positioned inside the outer conductor and may be filled with a dielectric.
The switching portion may be a rotor; the terminals of the plurality of microwave transmission lines may be arranged evenly spaced in the housing; and the rotor may be switched between the first position and the second position by rotating the rotor by a predetermined angle.
An even spacing of the terminals in the housing is not required but advantageous for simple manufacturing and replaceability of the switch. A rotor is a mechanical possibility for switching between positions. The predetermined angle by which the rotor is rotated from one position to the next position depends on the arrangement of the terminals in the housing and on the arrangement of the transmission lines in the switch and may or may not be equal to the angular distance between two adjacent terminals.
The rotor may be switchable between the second position and a third position and between the third position and a fourth position, wherein the rotor may be switched from the first position over the second position and the third position to the fourth position by rotating the rotor in a clockwise direction in steps of 90 degrees.
There may also be more than four positions of the rotor.
The switching portion may comprise a second junction portion for selectively interconnecting terminals of the plurality of microwave transmission lines, wherein the switching portion with the first junction portion and the second junction portion may be dimensioned and positioned inside the housing in dependence of the arrangement of the plurality of microwave transmission lines such that the first junction portion interconnects the first group of terminals of the plurality of microwave transmission lines and the second junction portion interconnects a third group of terminals of the plurality of microwave transmission lines when the switching portion is in the first position, and the first group of terminals and the third group of terminals may be disjoint groups of terminals.
In two disjoint groups of terminals, a terminal belonging to one group cannot belong to the other group at the same time. With at least two separate junction portions within the same switch, at least two transmission pathways that are isolated from each other can be provided. When such a switch is used as a switchable element in a circuit configuration, the number of switches required for reconfiguring the connections within the circuit can be greatly reduced.
The first group of terminals may comprise four terminals of the plurality of microwave transmission lines, the third group of terminals may comprise four terminals of the plurality of microwave transmission lines, the first junction portion may interconnect the four terminals of the first group of terminals when the switching portion is in the first position, the second junction portion may interconnect the four terminals of the third group of terminals when the switching portion is in the first position, and the switching portion is switched between two positions of a total of eight positions by rotating the switching portion in a clockwise direction in steps of 45 degrees.
This structure is advantageous for guiding signals from three input terminals to one output terminal, with the possibility to change the allocations according to varying transmission services demands.
Another aspect of the disclosure relates to a multiplexer for combining and/or separating electromagnetic signals, comprising a plurality of signal ports for inputting electromagnetic signals into the multiplexer or outputting electromagnetic signals from the multiplexer; a plurality of signal filters for filtering electromagnetic signals; one or more branching junctions for combining electromagnetic signals or for distributing an electromagnetic signal; wherein each signal filter is connectable to a signal port of the plurality of signal ports and to a branching junction of the one or more branching junctions or connectable to two branching junctions of the one or more of branching junctions; the plurality of signal ports comprising a first common signal port that is connectable to a branching junction of the one or more branching junctions; and the one or more branching junctions comprising the microwave branching switch for selectively interconnecting signal filters of the plurality of signal filters and the first common signal port.
The multiplexer has a single input port and multiple output ports, or multiple input ports and a single output port, or multiple input ports and multiple output ports. Preferably, the signal filters are formed as bandpass filters which transmit signals of predetermined frequency bandwidths. They can also be realized as other types of filters. A branching junction is a connection point in the transmission line network of the multiplexer where at least three transmission lines are interconnected. A signal arriving at this point from a transmission line is directed (distributed) to the other transmission lines connected at this point. Signals arriving at this point from multiple transmission lines connected at this point are directed to the other transmission lines connected at this point as a single (combined) signal. A connectable component of the multiplexer is a component that is connected to another component of the multiplexer in a first state of the multiplexer but is disconnected from the other component in a second state of the multiplexer. That is, a connectable component need not be connected to the multiplexer configuration all the time. Switching between the first state and the second state is performed by operating a switch (for example, a microwave branching switch as described above or a conventional switch) of the multiplexer. The multiplexer may be a manifold multiplexer.
Since the microwave branching switch combines branching and switching functions within a single functional component, it enables a flexible but still compact configuration of the multiplexer. Furthermore, this solution is scalable, providing a large technical gain with limited technical change.
With a multiplexer that is reconfigurable in this manner, changing the service or capacity demands is accommodated by a flexible re-allocation of transmission channels. For example, in a multiplexer comprising four channels and a microwave branching switch, three of the four channels can be multiplexed in different ways depending on the setting of the microwave branching switch. Another advantage is a less complex realization of a multiplexer with more than one output port, allowing for a flexible allocation of specific channels to either one of the output ports, which is useful for example in the case of satellite based communications systems for serving different service areas with a varying transmission capacity.
The multiplexer also enables the realization of an OMUX providing several output ports for serving different service areas, wherein some of the multiplexer channels are combined and served at the first output port while the remaining channels are served at the second output port. The use of microwave branching switches as manifold T-junctions in the multiplexer facilitates a flexible assignment of dedicated channels to the first or second output port. Thus, the transmission capacity, i.e. the number of channels dedicated to an output port, can be changed between the two output ports, for example to accommodate flexible re-allocations for different services.
Furthermore, the microwave branching switch can be used in reconfigurable multiplexers where overlapping frequency bands or different frequency bands need to be switched.
Also, waveguide circuitries comprising the microwave branching switch can be switched so as to compensate for contiguous and non-contiguous channel allocations. An example is a tunable filter implementation where channel frequencies can be arbitrarily close or far-distance.
Due to the dual functionality of splitting and switching, the inventive multiplexer also results in cost savings, for instance in telecom services for flexible payloads, in reduced integration effort, during manufacturing, or maintenance; reconfigurable multiplexer designs using the microwave branching switch may yield a reduction of necessary OMUX equipment compared with state-of-the-art implementations and thus a reduction of interconnections and switch hardware and a reduction of mass in satellite applications due to the reduced complexity.
Finally, the inventive multiplexer enables a more compact realization of the functionalities of conventional multiplexers.
Further application areas are multibeam and broadcast missions, navigation applications, antenna systems or radio applications.
The plurality of signal ports may comprise a second common signal port that is connectable to a branching junction of the one or more branching junctions; the microwave branching switch may interconnect a first group of signal filters of the plurality of signal filters and the first common signal port when the switching portion of the microwave branching switch is in the first position and the microwave branching switch may interconnect a second group of signal filters of the plurality of signal filters and the second common port when the switching portion of the microwave branching switch is in the second position.
Thereby, the structure of a switchable multiplexer with more than one common port, for example with two output ports, is simplified.
The multiplexer may further comprise a compensation circuit that is connectable to a terminal of the plurality of microwave transmission lines of the microwave branching switch for providing a predetermined impedance at the terminal.
A compensation circuit is a circuit which emulates an impedance with a predefined characteristic over a frequency range of interest. The compensation circuit may be realized as one or more coupled resonators. Thus, the compensation circuit is considered in case of changing contiguous to non-contiguous channel schemes to compensate for the impedance of the missing adjacent filter in the non-contiguous channel allocations.
Each junction portion in the multiplexer may be directly connected to one signal filter of the plurality of signal filters for interconnecting the one signal filter and either the first common signal port or the second common signal port.
If a junction portion is directly connected to a signal filter, it means that in addition to the junction portion being connected to the signal filter, there is no branching junction (unswitchable or switchable in the form of another junction portion) set between the junction portion and the signal filter.
Thereby, the allocation of a specific signal filter to the signal ports can be changed independently of the allocations of other signal filters to the signal ports.
Alternatively, at least one junction portion in the multiplexer may be directly connected to at least two signal filters of the plurality of signal filters for simultaneously interconnecting the at least two signal filters and either the first common signal port or the second common signal port.
Thus, the frequency allocation of two signal filters to the signal ports can be changed in a simple manner.
Another aspect of the disclosure relates to a switchable power divider for a beam forming network, comprising at least three antenna beams; a common port; and the microwave branching switch for selectively interconnecting antenna beams of the at least three antenna beams and the common port, wherein the microwave transmission lines of the microwave branching switch differ in size for providing different power levels at the terminals of the microwave branching switch.
Thereby, an active beam forming is possible and different beams can be combined or severed. The difference in size can be realized by providing microwave transmission lines with different cross sections, for example. The output signal of the switchable power divider is preferably frequency-independent.
In the following, the invention will be described in an exemplary manner with reference to the appended figures. Identical elements in the figures may be indicated by identical reference numbers, and repeated description thereof may be omitted.
The microwave branching switch 1 further comprises a switching portion 30 in the form of a circular rotor that is rotatable around its center point by operating the actuator 40. The boundary of the switching portion 30 divides a transmission line 11; 12; 13; 14 into two parts (in
Which ones of the transmission lines 11-14 are connected in the switching portion 30 and which one is disconnected from the connected transmission lines is defined by the current position of the switching portion 30.
It should be noted that the junction portion 31 might also exhibit discontinuities like posts or irises aiming at a specific impedance characteristic over the frequency band of interest, e.g. for improving the inherent matching properties of the junction portion 31 and/or the response of the overall component design.
The function of the exemplary multiplexer 100 in
This is, the microwave switch 1 in combination with the respective channel filters 120 (ch1, ch2) provide the separation of the respective channel signals fed to the common port 111. These are routed to the respective output ports 110 (for ch1 directly and for ch2 via the conventional switch 2). To change the channel frequency allocation of ch2 to ch2a for another service requirement like that shown in the scheme of
Therefore, referring to
Regarding its connection configuration, the input port in
One of the input ports is connected to a signal filter 120 associated with a channel allocation f2 that is in turn connected to a microwave branching switch 1. Depending on the position of the switching portion 30 of the switch 1, a signal passing through the signal filter 120 associated with f2 is directed either to the first common signal port 111 or to the second common signal port 112. In the first case, the signals of the dedicated channel f1 (left in
It should be noted that f1 and f2 (and f3 in some of the examples below) might also refer to power distributions instead of frequency ranges, or to any other signal characteristic that might be filtered by a signal filter 120.
The functional complexity of the multiplexer 100 in
For example, if the switch 1 is in the second position (as shown), the power available at the common port 221 corresponds to the combined power of feeds 211a and 211b. If the switch 1 is in the fourth position, the power available at the common port 221 corresponds to the combined power of antenna beams 211b and 211c. If the switch 1 is in the first position, the power available at the common port 221 corresponds to the combined power of antenna beams 211a and 211c.
It should be noted that the description and drawings merely illustrate the principles of the proposed apparatus. Those skilled in the art will be able to implement various arrangements that, although not explicitly described or shown herein, embody the principles of the invention and are included within its spirit and scope. Furthermore, all examples and embodiments outlined in the present document are expressly intended to be for explanatory purposes only to help the reader understand the principles of the proposed apparatus. Furthermore, all statements herein providing principles, aspects, and embodiments of the invention, as well as specific examples thereof, are intended to encompass equivalents thereof.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2015/067815 | 8/3/2015 | WO | 00 |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO2017/020948 | 2/9/2017 | WO | A |
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| Number | Date | Country | |
|---|---|---|---|
| 20180226705 A1 | Aug 2018 | US |
