Abstract
A microwave branching switch for selectively interconnecting terminals of a plurality of microwave transmission lines, involving microwave transmission lines with a terminal; a housing in which the terminals are arranged; a switching portion with a junction portion for selectively interconnecting terminals of the microwave transmission lines through selective interconnection. The switching portion is switchable between a first position and a second position; wherein the switching portion with the junction portion is dimensioned and positioned inside the housing in dependence of an arrangement of the microwave transmission lines such that the junction portion interconnects a first group of terminals when the switching portion is in the first position and interconnects a second group of terminals when the switching portion is in the second position. The first and second groups of terminals differ in at least one terminal and the first group of terminals involves at least three terminals.
Claims
1. A microwave branching switch, comprising: a plurality of microwave transmission lines and a plurality of terminals, each of the plurality of microwave transmission lines having a respective terminal from the plurality of terminals, the plurality of microwave transmission lines including 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 plurality of terminals of the plurality of microwave transmission lines are arranged; a switching portion being switchable between at least a first position and a second position, the switching portion comprising 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 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 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 at least one of the first group of terminals or the second group of terminals comprises the first terminal, the third terminal and the fourth terminal; wherein at least another terminal of the plurality of terminals is disconnected from the plurality of microwave transmission lines, the at least another terminal comprising a portion that is positioned inside the switching portion and is terminated by an impedance, a load, or a short circuit.
2. The microwave branching switch according to claim 1, wherein the second terminal is 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 is disconnected from the first junction portion when the switching portion is in the second position.
3. The microwave branching switch according to claim 1, wherein the first junction portion is T-shaped or Y-shaped.
4. The microwave branching switch according to claim 1, wherein the plurality of microwave transmission lines is a plurality of hollow waveguides or a plurality of coaxial lines.
5. The microwave branching switch according to claim 1, wherein the switching portion is a rotor; the terminals of the plurality of microwave transmission lines are arranged evenly spaced in the housing; and the rotor is switched between the first position and the second position by rotating the rotor by a predetermined angle.
6. The microwave branching switch according to claim 5, wherein the rotor is switchable between the second position and a third position and between the third position and a fourth position, wherein the rotor is 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.
7. The microwave branching switch according to claim 1, wherein the switching portion comprises a second junction portion, wherein the switching portion with the first junction portion and the second junction portion is 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 are disjoint groups of terminals.
8. The microwave branching switch according to claim 7, wherein comprises four terminals of the plurality of microwave transmission lines and the third group of terminals comprises four terminals of the plurality of microwave transmission lines, and the first junction portion interconnects the four terminals of the first group of terminals when the switching portion is in the first position, and the second junction portion interconnects 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.
9. A multiplexer, 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 plurality 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; the one or more branching junctions comprising a microwave branching switch according to claim 1 for selectively interconnecting signal filters of the plurality of signal filters and the first common signal port.
10. The multiplexer according to claim 9, wherein the plurality of signal ports comprises a second common signal port that is connectable to a branching junction of the one or more branching junctions; the microwave branching switch interconnects 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 interconnects 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.
11. The multiplexer according to claim 9, further comprising 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.
12. The multiplexer according to claim 11, wherein each junction portion in the multiplexer is 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.
13. The multiplexer according to claim 11, wherein at least one junction portion in the multiplexer is 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.
14. A switchable power divider for a beam forming network, comprising at least three antenna beams; a common port; and a microwave branching switch according to claim 1 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.
Description
BRIEF DESCRIPTION OF THE FIGURES
(1) FIGS. 1A-1B schematically illustrate an example of a microwave branching switch according to embodiments of the disclosure in the first position.
(2) FIGS. 2A-2B schematically illustrate another example of a microwave branching switch according to embodiments of the disclosure in the first position.
(3) FIGS. 3A-3B schematically illustrate examples of a microwave branching switch according to embodiments of the disclosure in the second position.
(4) FIG. 4 schematically illustrates an example of a microwave branching switch according to embodiments of the disclosure in the first to fourth positions.
(5) FIGS. 5A-5B schematically illustrate an example of a multiplexer according to embodiments of the disclosure.
(6) FIGS. 6A-6B schematically illustrate another example of a multiplexer according to embodiments of the disclosure.
(7) FIGS. 7A-7B schematically illustrate another example of a multiplexer according to embodiments of the disclosure.
(8) FIGS. 8A-8D schematically illustrate another example of a multiplexer according to embodiments of the disclosure.
(9) FIGS. 9A-9F schematically illustrate another example of a multiplexer according to embodiments of the disclosure.
(10) FIGS. 10A-10B schematically illustrate another example of a multiplexer according to embodiments of the disclosure.
(11) FIG. 11 schematically illustrates another example of a multiplexer according to embodiments of the disclosure.
(12) FIG. 12 schematically illustrates an example of a switchable power divider according to embodiments of the disclosure.
(13) FIG. 13 schematically illustrates an example of a conventional waveguide switch.
(14) FIGS. 14A-14B schematically illustrate an example of a conventional multiplexer.
(15) FIG. 15 schematically illustrate another example of a conventional multiplexer.
DETAILED DESCRIPTION
(16) 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.
(17) FIGS. 1A/1B illustrate an example of a microwave branching switch 1. FIG. 1A is a sectional view along the line A-A in FIG. 1B. The first to fourth microwave transmission lines 11-14 in this exemplary microwave branching switch 1 are waveguides. The waveguides may be straight, rigid tubes having a rectangular cross section. However, the waveguides might also be ridge waveguides or dielectric waveguides (waveguides filled with a dielectric). The transmission lines 11-14 are preferably but not necessarily positioned on the same level in the housing 20. Their positioning inside the housing 20 can also be inclined. The connection to transmission lines 150 outside of the housing 20 is achieved by terminals 21-24 in the housing 20. Each transmission line 11-14 is associated with a terminal 21-24 in the housing such that terminal 21 is positioned at an end portion of transmission line 11, terminal 22 is positioned at an end portion of transmission line 12, terminal 23 is positioned at an end portion of transmission line 13 and terminal 24 is positioned at an end portion of transmission line 14.
(18) 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 FIG. 1A the transmission lines 11, 13, 14) or terminates a transmission line 11; 12; 13; 14 (in FIG. 1A the transmission line 12). Three of the four transmission lines 11-14 are connected at the center of the switching portion 30 while the fourth transmission line 11; 12; 13; 14 is disconnected from the three connected transmission lines. The disconnected transmission line is connected to a short circuit, a load or a predetermined impedance 33 which is part of the switching portion. The parts of the transmission lines 11-14 that are connected inside the switching portion 30 are termed first junction portion 31. The first junction portion 31 has a T-shape in the example of the switch 1 illustrated in FIG. 1A.
(19) 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. FIG. 1A shows a microwave branching switch 1 with the switching portion 30 set in the first position. The switch 1 can be switched from the first position into the second position by rotating the switching portion 30 in a clockwise direction by 90 degrees (indicated by the arrow). The available positions for this exemplary switch 1 are described in more detail in the context of FIG. 4.
(20) FIGS. 2A/2B illustrate another example of a microwave branching switch 1. FIG. 2A is a sectional view along the line B-B in FIG. 2B. The microwave branching switch 1 is a coaxial switch, meaning the first to fourth microwave transmission lines 11-14 are coaxial lines filled with a dielectric and comprising inner conductors 111, 121, 131, 141 and outer conductors 112, 122, 132, 142. The microwave branching switch 1 of FIGS. 2A/2B is similar to the microwave branching switch 1 of FIGS. 1A/1B. In particular, the switch 1 in FIG. 2A is also in the first position, with the second transmission line 12 disconnected from the first, third and fourth transmission lines 11, 13 and 14. In the example of FIG. 2A, a part of the disconnected transmission line 12 remains inside the switching portion 30 and may be terminated into a short circuit, a load or a predetermined impedance 33. Such a termination of the disconnected transmission line 12 might be realized also in the following examples showing a microwave branching switch 1, even if this is not explicitly denoted.
(21) FIG. 3A shows an exemplary microwave branching switch 1 in the second position. The structure of the switch 1 is similar to that illustrated in FIG. 1A except for the housing 20 not being shown. In FIG. 3A, the switching portion 30 connects the first, second and fourth transmission lines 11, 12, 14 while the third transmission line 13 is disconnected from the T-shaped junction portion 31. The disconnected transmission line 13 may be terminated into a short circuit, a load or a predetermined impedance 33 inside the switching portion 30.
(22) FIG. 3B shows another example of a microwave branching switch 1 in the second position. The structure of the switch 1 is similar to the switch 1 illustrated in FIG. 3A except for the shape of the junction portion 31 which in this case is Y-shaped. T- or Y-shaped junction portions 31 are preferable for connecting exactly three transmission lines.
(23) 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.
(24) FIG. 4 shows the available positions for a microwave branching switch 1 wherein three terminals out of four terminals 21-24 are connected by connecting three microwave transmission lines out of four microwave transmission lines 11-14 inside the switching portion 30. FIG. 4 shows only the switching portion 30. From left to right, the four available positions of the switching portion 30 are illustrated starting with the first position on the left hand side. The first, third and fourth transmission lines 11, 13, 14 are connected in the first position, the first, second and fourth transmission lines 11, 12, 14 are connected in the second position, the first, second and third transmission lines 11, 12, 13 are connected in the third position, and the second, third and fourth transmission lines 12, 13, 14 are connected in the fourth position. The switch 1 can be switched between any two adjacent positions by rotating the switching portion 30 by 90 degrees in the clockwise direction or in the counter-clockwise direction. The microwave branching switch 1 is not restricted to connecting three transmission lines or to comprising a single junction portion 31 but might also connect more than three transmission lines and/or might comprise more than one junction portion 31. A corresponding example is illustrated in FIG. 11. In this case, more than four different positions (eight different positions for the switch 1 of FIG. 11) may exist for the switching portion 30.
(25) FIG. 5A shows an exemplary implementation of a microwave branching switch 1 in a multiplexer configuration. In this figure and the following figures, illustrations of the microwave branching switch 1 only show the switching portion 30 for a better overview. The multiplexer 100 comprises three signal ports 110 of which the one shown on the left is used as an input port and the ones shown on the right are used as output ports. The multiplexer 100 further comprises three signal filters 120 as bandpass filters and two switches 1, 2, of which one is a microwave branching switch 1 and the other is a conventional switch 2. Signal transmission lines 150 connect the components of the multiplexer 100.
(26) The function of the exemplary multiplexer 100 in FIG. 5A is to provide the separation of two channels (ch1, ch2/ch2a) where one of the channels (ch2, ch2a) can be re-allocated for flexible service of different dedicated channel requirements, e.g. having an overlapping frequency range. The microwave branching switch 1 serves as the branching for the common input signal of the multiplexer 100 connecting the common (input-) port 111 with the respective channel filters (ch1, ch2/ch2a). FIG. 5A shows the configuration of the multiplexer 100 for serving frequency channels ch1 and ch2 that may have for example a frequency assignment according to the channel scheme depicted in FIG. 5B top.
(27) 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 FIG. 5B bottom, the switching positions of the microwave switch 1 is altered by 180 and that of the conventional switch 2 by 90. Thus, the respective channel signal (ch1, ch2a) at the common port 111 for ch2a is now routed via the microwave switch 1, the respective channel filter 120 and the conventional switch 2 to the bottom output port 110; while the routing of the signal of ch1 is maintained via the microwave switch 1 and the respective channel filter 120 to the top output port 110 (cf. FIG. 5A).
(28) Therefore, referring to FIG. 14A, the same functionality of the multiplexer 4 of FIG. 14A is provided by the multiplexer 100 of FIG. 5A while, by implementing a microwave branching switch 1, the overall configuration is greatly simplified. Specifically, the number of necessary components is reduced (less switches 1, 2 and less transmission lines 150), and the signal filter 120 associated with the bandwidth ch1 that is to be provided at the output in any case does not need to be duplicated thanks to the branching function of the first junction portion 31 of the microwave branching switch 1.
(29) Regarding its connection configuration, the input port in FIG. 5A differs from the output ports in FIG. 5A in that the input port is connectable to two signal filters 120 at the same time while each of the output ports is connectable to only one signal filter 120 at the same time. A signal port 110 which is connectable to more than one signal filter 120 at the same time, for example via a microwave branching switch 1 or via an (unswitchable) branching junction 130, may be called a common signal port 111, 112, 113 in the following.
(30) FIG. 6A shows another example of a multiplexer 100, illustrating the capability of allocating a channel associated with a signal filter 120 to one of the common signal ports 111, 112. The multiplexer 100 comprises three signal ports 110 for inputting signals into the multiplexer 100 as well as a first common signal port 111 and a second common signal port 112 for outputting signals from the multiplexer 100. Each of the input ports is connected to a signal filter 120. Two of the signal filters 120 pass signals with a channel allocation f1 and are connected to the first common signal port 111 or the second common signal port 112 by way of fixed branching junctions 130 for providing the channel allocation f1 at both common signal ports 111, 112 independently of the switching state of the multiplexer 100. The frequency allocations of f1 served at the outputs are dedicated to different services (i.e. service areas), which allows for a frequency reuse of the channel, meaning that although they have the same frequency band, they are serving independent signals.
(31) 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 FIG. 6A) and channel f2 are provided at the first common signal port 111 (cf. top scheme of FIG. 6B) while the respective signals of channel f1 are provided at the second common signal port 112 (cf. bottom scheme of FIG. 6B). When changing the switch configuration by 180, the signals of channel f1 (left in FIG. 6A) are provided at the first common signal port 111 while the channel signals of channel f1 (right in FIG. 6A) and f2 are provided at the second common signal port 112 (not shown in FIG. 6B). Therefore, the channel f2 can be allocated/combined to either common signal port 111, 112. The unused transmission line of the switch 1 (the transmission line not serving the purpose of connecting a signal filter 120 and a signal port 110; in FIG. 6A: the third transmission line 13) may be connected to a short circuit, to a load, or to any compensation circuitry, for example.
(32) 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.
(33) FIG. 7A shows another example of a multiplexer 100 with three common signal ports 111-113, three signal filters 120 and three microwave branching switches 1a-1c. The first and second common signal ports 111, 112 are used as output ports; the third common signal port 113 is used as an input port. With this configuration, each signal filter 120 can be selectively allocated to the first and second common signal ports 111, 112. For example, using the numbering of positions according to FIG. 4, the switch 1a can be set in the second position, the switch 1b can be set in the first position and the switch 1c can be set in the third position for allocating the signal filters 120 with channel allocations f1 and f2 to the first common signal port 111 and the signal filter 120 with channel allocation f3 to the second common signal port 112 (top scheme of FIG. 7B). If the switch 1b is switched from the first position to the third position and switch 1c is in the second position, the signal filter 120 serving channel f2 is disconnected from the first common signal port 111 and allocated to the second common signal port 112 (bottom scheme of FIG. 7B).
(34) FIGS. 8A and 8C show an example of a multiplexer 100 similar to the example shown in FIG. 6A, where all branching junctions 130 are realized as microwave branching switches 1a-1c. Since f1 and f2 are contiguous frequency channels, it is preferable to provide a possibility for a selective connection of the f1 channel with a compensation circuit 140 with regard to compensating the contiguous/non-contiguous situation in cases of combining/disconnecting the adjacent channel. For example, in FIG. 8A, the channels f1+f2 are allocated to the first common signal port 111 (top scheme in FIG. 8B) and the channel f1 is allocated to the second common signal port (bottom scheme of FIG. 8B). Additionally, the signal filter 120c is connected to a compensation circuit 140 via the switch 1c.
(35) FIG. 8C shows the same multiplexer 100 with all switches 1a-1c being switched so as to provide f1 at the first common signal port 111 (top scheme of FIG. 8D) and f1+f2 at the second common signal port 112 (bottom scheme of FIG. 8D). For this configuration, the signal filter 120c is disconnected from the compensation circuit 140 while the signal filter 120a for allocating f1 to the port 111 is connected to the respective compensation circuit 140 via the switch 1a.
(36) FIGS. 9A, 9C and 9E show a multiplexer 100 which serves the same purpose as the conventional multiplexer 4 in FIG. 15. That means that the channels f1 are served at both common signal ports 111, 112 (frequency reuse for different services) while f2 and f3 are selectively and independently allocated to one of the common signal ports 111, 112. Compared with the multiplexer 4 in FIG. 15, the multiplexer 100 in FIGS. 9A, 9C and 9E comprises four microwave branching switches 1a-1d instead of two conventional switches 2a, 2b, four signal filters 120 instead of six signal filters 120 and a less complicated structure of connecting transmission lines 150. In order to change the signal output as shown in FIG. 9B to an output as shown in FIG. 9D, the switch 1c is switched from the second position to the third position and the switch 1d is switched from the third position to the second position. In order to change the signal output as shown in FIG. 9D to an output as shown in FIG. 9F, switch 1a is switched from the second position to the first position, switch 1b is switched from the second position to the third position and switch 1c is switched from the third position to the second position.
(37) The functional complexity of the multiplexer 100 in FIGS. 9A, 9C and 9E is therefore comparable to the complexity of the multiplexer 4 in FIG. 15, however, using microwave branching switches 1 instead of conventional switches 2 results in a considerable saving of filter hardware (4 instead of 6) and harness due to a decreased overall length of required transmission lines 150, yielding a reduction of insertion loss, complexity and mass. This is especially advantageous for applications in space, like for example in satellites.
(38) FIG. 10A illustrates a multiplexer 100 for simultaneously allocating two signal filters 120b, 120d with associated channels f1, f3 contiguous to the channel associated with the allocated signal filters 120a, 120c. All branching junctions 130 are realized as microwave branching switches 1a-1c in the multiplexer 100 in FIG. 10A; the switches 1a and 1c being connected to compensation circuits 140 similar to FIGS. 8A, 8C. The whole configuration can be switched so as to provide f1+f2+f3 at the first common signal port 111 and f2 at the second common signal port 112 (two top schemes in FIG. 10B) or so as to provide f2 at the first common signal port 111 and f1+f2+f3 at the second common signal port 112 (two bottom schemes in FIG. 10B), corresponding to a capacity re-allocation at the output ports. In this case, the switches 1a and 1c are not used for changing the allocation of signal filters 120 to common ports 111, 112 but for selectively adding compensation circuits 140 to the multiplexer circuit.
(39) FIG. 11 shows a further example of a multiplexer 100 comprising a further example of a microwave branching switch 1. The microwave branching switch 1 comprises a switching portion 30 with a first junction portion 31 interconnecting four terminals 21-24 by interconnecting four microwave transmission lines 11-14 and a second junction portion 32 interconnecting four terminals 25-28 by interconnecting four microwave transmission lines 15-18. In the shown position of the switching portion 30, signal transmission lines 150 connecting three signal filters 120a-120c to the switch 1 are interconnected in the connection point of the first junction portion 31 such that signals transmitted by filters 120a-120c are combined and guided towards the second common signal port 112 via the transmission line 14. Furthermore, signal transmission lines 150 connecting three signal filters 120d-120f to the switch 1 are interconnected in the connection point of the second junction portion 32 such that signals transmitted by filters 120d-120f are combined and guided towards the first common signal port 111 via the transmission line 18. The switch 1 is switched to the next position by a clockwise (or counter-clockwise) rotation of the switching portion 30 by 45 degrees. In total, eight different positions are available for the switching portion 30. Thereby, a group of three signal filters 120 can be allocated to one signal port 110 while another group of three signal filters 120 can be allocated to another signal port 110, isolated from the first group.
(40) FIG. 12 illustrates a switchable power divider 200 e.g. for feeding three antenna beams 211a-211c, a microwave branching switch 1, a common port 221 and connecting signal transmission lines 150. The power divider 200 enables a selective power distribution at the common port 221.
(41) 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.
(42) 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.
LIST OF REFERENCE NUMERALS
(43) 1, 1a-1d microwave branching switch 2, 2a-2c conventional switch 3 conventional switching portion 4 conventional multiplexer 11 first microwave transmission line 12 second microwave transmission line 13 third microwave transmission line 14 fourth microwave transmission line 15-18 fifth to eighth microwave transmission lines 111, 121, 131, 141 inner conductors 112, 122, 132, 142 outer conductors 20 housing 21 first terminal 22 second terminal 23 third terminal 24 fourth terminal 25-28 fifth to eighth terminals 30 switching portion 31 first junction portion 32 second junction portion 33 impedance, load or short circuit 40 actuator 100 multiplexer 110 signal port 111 first common signal port 112 second common signal port 113 third common signal port 120, 120a-120f signal filter 130 branching junction 140 compensation circuit 150 signal transmission line 200 power divider 211, 211a-211c antenna beam 221 common port
