JP2007043746A - Switch - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To accomplish a switch suitable for a broadcasting station, a repeater station and the like in a terrestrial digital television broadcasting system. <P>SOLUTION: The switch comprises: a plurality of high frequency lines connecting input sources and output destination in a high-frequency manner; a switching circuit provided for each high frequency line for line-selectively blocking high-frequency connection; and a drive circuit for driving the switching circuits. At least any one of the switching circuits is a shunt circuit S and in the high frequency lines, a line portion including a spot where the shunt circuit S is disposed, and having an electrical length of a natural multiple of λ/2 (λ: carrier wavelength of signal propagated on high frequency line) across an input source side and an output destination side is a line portion having a low peculiar impedance relative to line portions, located at the input source side and the output destination side, in the view from the line portion. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a switch for selectively connecting any one of a plurality of input sources to a predetermined output destination.

  Redundancy of the number of wireless transmitters is one of the effective methods for improving reliability. The number redundancy here means, for example, that one of the two radio transmitters is used as active and the other is used as a spare, and these working transmitter and spare transmitter are connected to a transmitting antenna via a switch. Point to. If the wireless transmitter is made redundant in this way, the active transmitter is usually connected to the transmitting antenna for use, but if maintenance or maintenance is necessary, the switch is operated and controlled. It is possible to adopt a mode of operation such as connecting a spare transmitter to the transmitting antenna, so that transmission can be continued almost seamlessly except for the short time required for the operation of the switch, and the state of each wireless transmitter is good The reliability and quality of the transmission service are remarkably improved as compared with the case where transmission is performed by a single wireless transmitter, such as easy maintenance. If a switch having a mode in which a plurality of radio transmitters are connected to a transmission antenna is used, these radio transmitters (in this mode, there is no distinction between active / spare) can be used for transmission at the same time. it can.

  As described above, redundancy using a switch for selectively connecting any one of a plurality of input sources to a predetermined output destination is a system that wants to continue to provide a transmission service without interruption, such as a terrestrial TV. It is used in the John Broadcasting System. In this type of system, for example, two broadcasting machines (No. 1 and No. 2) are provided in a broadcasting station. Furthermore, the output from any one of the broadcast signal outputs of the No. 1 and No. 2 units, for example, the broadcast signal output from the No. 1 unit, is sent to the transmitting antenna (or various circuits in the preceding stage through a switch). Supplied to the transmitting antenna). In this case, the broadcast signal output from the first unit is radiated from the transmission antenna. When it is desired to stop Unit 1 for some reason, such as repairing a faulty part, the Unit 1 is disconnected from the transmitting antenna by operating and controlling the switch, and the Unit 2 is connected to the transmitting antenna. Broadcasting continues with Unit 2. In this way, by making the number of broadcasters redundant and selectively using a switch, it is possible to improve the reliability of the broadcast system, especially at the appropriate time including the broadcast time zone. It is possible to continue transmission without interruption while performing maintenance and the like.

  A problem inherent in such a multi-transmitter system is that signal transmission is interrupted even if the time required for switching by the switch is small. This problem, that is, the problem of instantaneous transmission interruption, tends to become more prominent in a system that transmits a signal with a high information compression rate and in a system that transmits a signal modulated at high speed. For example, in Japan, commercial operation of a terrestrial digital television broadcasting system is scheduled to begin in the near future from the time of filing of the present application. In a terrestrial digital television broadcasting system, highly compressed data is wirelessly transmitted or broadcasted at a high speed using a large number of carriers. For this reason, compared to a terrestrial analog television broadcasting system or the like that has been provided with services in the past, an instantaneous interruption of a broadcast wave is a problem that tends to cause a loss of synchronization on the television receiver side. Under such circumstances, conventionally, a switch has been developed and improved so that a signal path can be switched as fast as possible. In particular, in a switch that handles high-power high-frequency signals such as a switch for broadcasting stations, it is necessary to ensure not only high-speed switching, but also high-frequency signal isolation and resistance to high-power signals. Therefore, development and improvement that takes that aspect into account are being carried out.

  11 and 12 show the configuration of a switch belonging to the prior art. The switch shown in FIG. 11 is configured according to a system called a multiple switch system and the one shown in FIG. 12 is a system called a crossover system, which are described in Non-Patent Documents 1 and 2, respectively.

  The apparatus shown in FIG. 11 has inputs 1 and 2 as input terminals connected to the broadcaster side, and as an output terminal connected to a terminal connected to the transmission antenna ANT and a dummy load RD for matching absorption. Terminal. The input 1 is connected to the switches SW1 and SW2 via a λ / 2 line loaded with λ / 4 short stubs STB1 and STB2 at the center (λ: broadcast signal carrier wavelength). The input 2 is connected to the switches SW1 and SW2 via a λ / 2 high-frequency line loaded with λ / 4 short stubs STB3 and STB4 at the center thereof. The switches SW1 and SW2 are respectively connected to the transmission antenna ANT via a λ / 2 line and to the dummy load RD via a λ / 2 line. However, of these λ / 2 lines, a part of the line between SW1 and ANT is realized by a λ / 4 fixed matching unit M1, and a part of the line between SW2 and RD is realized by a λ / 4 fixed matching unit M2. .

  Further, the switches SW1 and SW2 are respectively a high frequency line connecting the input 1 and the transmission antenna ANT, a high frequency line connecting the input 2 and the transmission antenna ANT, a high frequency line connecting the input 1 and the dummy load RD, And a high-frequency line connecting the input 2 and the dummy load RD. Each of the four high-frequency lines included in each of the switches SW1 and SW2 has a mechanical configuration in order to allow / inhibit signal transmission through the high-frequency lines, that is, to control signal transmission selectively. A contact is provided. These mechanical contacts denoted by reference numerals 1 to 4 in the figure can be contact-type contacts that involve opening and closing of mechanical contact, and non-contact-type contacts that are connected via capacitance. You can also Further, these contacts are driven by an electromagnetic solenoid that is excited / deenergized in accordance with a drive signal supplied from the solenoid drive control unit 10.

  Accordingly, for example, a transmission path of “input 1 → transmission antenna ANT, input 2 → dummy load RD” is instructed to the solenoid drive control unit 10, the contacts 1 and 4 of the switch SW1 are closed, and the contacts 2 and 3 are opened. By controlling to the above, while broadcasting using a broadcaster (not shown) connected to the input 1, the output of the broadcaster (not shown) connected to the input 2 can be absorbed by the dummy load RD. it can. In addition, since two switches (SW1, SW2) are provided in parallel, the outputs of both broadcasters can be combined to increase the power and radiate from the transmitting antenna ANT.

  The apparatus shown in FIG. 12 has a hybrid HYB1 connected to two input terminals, that is, inputs 1 and 2, a hybrid HYB2 connected to a transmission antenna ANT and a dummy load RD, and two phase shifters. It is configured. Each phase shifter is constituted by a hybrid HYB3 or HYB4 connected to the hybrids HYB1 and HYB2, and one-end grounded variable capacitors VC1 and VC2 or VC3 and VC4 connected to the hybrid HYB3 or HYB4. The variable capacitors VC <b> 1 to VC <b> 4 are driven by a drive signal supplied from the variable capacitor drive device 20 and change their capacitance. The hybrids HYB1 to 4 are, for example, 3 dB hybrids. A λ / 4 short stub STB5 is placed in front of the lower phase shifter in the figure.

  The switch shown in this figure is a unit 1 independent operation mode in which the output of a broadcasting device (not shown) connected to the input 1 is radiated from the transmission antenna ANT, and the broadcasting connected to the input 2 as an operation mode. A unit 2 independent operation mode in which the output of the broadcaster (not shown) is radiated from the transmission antenna ANT, and a parallel operation mode in which the outputs of both broadcasters are combined and radiated from the transmission antenna ANT. In the Unit 1 single operation mode, the phase shift amount by the upper phase shifter is increased by 90 ° relative to the phase shift amount by the lower unit phase shifter, and in the Unit 2 single operation mode, the variable shifter is decreased by 90 °. The driving device 20 drives the variable capacitors VC1 to VC4 in each phase shifter. In the parallel operation mode, the phase shift action is canceled by adding a 90 ° phase difference between the two inputs.

  In both the multiple switch system and the crossover system shown in FIGS. 11 and 12, since the contact can be a contact that does not involve opening and closing of mechanical contact, the frequency of failure of the contact can be reduced. Therefore, it has the advantage that the reliability can be improved. However, before or after switching from input 1 to input 2 or vice versa because it uses a contact (FIG. 11) or a variable capacitor (FIG. 12) with a mechanical drive even though it does not involve mechanical contact. In a transient period, power fluctuation and phase fluctuation are likely to occur in the output from the transmission antenna ANT. In addition, although the time required for switching can be shortened by using a contactor or a variable capacitor that does not involve opening and closing of mechanical contact as the mechanical contact described above, since it is a mechanical contact and therefore has a mechanical drive part, switching is possible. There is a limit to shortening the time required. Even if it is shortened as much as possible, for example, the method shown in FIG. 11 will require about 500 msec, and the method shown in FIG. Further, the method shown in FIG. 11 has a problem that the maintenance of the contacts is troublesome and difficult because a large number of mechanical contacts are used, and the method shown in FIG. 12 is currently used for transmission. There is a problem that the output of a broadcasting device that does not exist leaks slightly to the transmitting antenna ANT side and the isolation is not good and remains at most about 40 dB.

Japanese Patent Laid-Open No. 11-340945 JP 2000-261409 A JP-A-6-292157 "Development of non-stop synthesis switch for VHF TV broadcasting" (Sunagawa et al., Television Society Technical Report, vol.14, No.21, pp.1-6, RDFT'90-32 (March, 1990)) "Development of VHF high power crossover type non-stop switching system" (Sunagawa et al., Television Society Technical Report, RE81-28, pp77-82, announced on September 25, 1986) Pin Diode Handbook (issued by Microsemi, first edition: June 1, 1996, as of September 4, 2002, downloadable in PDF format from http://www.microsemi.com/literature/products/rf/pinbook.asp ), Especially Chapter One (http://www.microsemi.com/literature/products/rf/chapter%201.pdf)

  The present invention has been made to solve such problems, and the frequency of occurrence of wave breakage / damage due to malfunctions / failures in the contact and its surroundings is low, and broadcasting of a terrestrial digital television broadcasting system is possible. One of the purposes is to realize a switch suitable for a station, a relay station, or the like. In addition, the present invention can identify malfunction / failure location, improve isolation, suppress power fluctuation / phase fluctuation before / after switching / transition period, shorten switching time, facilitate maintenance / maintenance work, daytime Maintenance, small size, and low price can be achieved.

  The switching device according to the present invention is a switching device for selectively connecting any one of a plurality of input sources, for example, a plurality of broadcasters, to a predetermined output destination, for example, a transmission antenna. The switch according to the present invention is premised on a plurality of high-frequency lines that connect each input source and output destination in a high-frequency manner, and the high-frequency connection in a line-selective manner (that is, any one or a plurality of A switching circuit provided for each high-frequency line and a drive circuit for driving the switching circuit are provided to prevent (by appropriately selecting a high-frequency line). The switch according to one aspect of the present invention includes: (1) a plurality of switch circuits provided for at least one of the plurality of high-frequency lines; and (2) a drive circuit provided for each switch circuit. It is characterized.

  Since the switch circuit in the switch is for selectively blocking high-frequency connection by the high-frequency line in the switch, it is basically sufficient to provide one switch circuit for each high-frequency line. Nevertheless, the reason why a plurality of switch circuits are provided in a high-frequency line (at least one) in one embodiment of the present invention is to improve reliability and isolation.

  First, when providing a plurality of switch circuits on a high-frequency line, a plurality of switch circuits are provided at the same location on the high-frequency line so as to be parallel to each other, or switch circuits are provided at different locations on the high-frequency line. It can be provided, or a combination of both. As long as one of the plurality of switch circuits malfunctions or fails, the other switch circuits provided in parallel with the switch circuit function normally if the configuration is arranged in parallel at the same location. As long as it is not limited, the high-frequency connection allowance / blocking control by the corresponding high-frequency line is not hindered, and therefore, the effect of improving reliability by redundancy can be obtained. Furthermore, since they are arranged in parallel, the shared current of each switch circuit is reduced or the total current capacity / allowable loss is increased. Further, if the configuration is provided in different places, the isolation effect by each switch circuit acts synergistically, so that the isolation in the entire high-frequency line is remarkably increased. In the combination of both, that is, in the form in which a plurality of switch circuits are arranged in parallel at different locations, the above-described effects can be obtained together.

  In addition, in a circuit configuration in which a plurality of switch circuits are driven by a single drive circuit, if a malfunction or failure occurs in one of the plurality of switch circuits, the operation of the drive circuit or other switch circuits is affected. However, as a result, the effect of improving reliability and isolation may be impaired. Therefore, in the present invention, preferably, a drive circuit is provided for each switch circuit. In this way, since the drive circuit and the switch circuit are associated with each other, it is possible not only to prevent the spread of abnormality due to malfunction or failure, but also to identify the location where the abnormality has occurred through detection of the switch circuit abnormality by the drive circuit. It becomes possible. That is, a circuit example in which the switch circuit in the switch is realized by using a semiconductor element that conducts / cuts off according to the bias voltage, such as a PIN diode, and the bias voltage is applied from the drive circuit to the semiconductor element in the corresponding switch circuit. In other words, the bias status of the semiconductor element in the switch circuit to which each drive circuit corresponds is determined based on the output voltage or current of the drive circuit, and based on the result, whether there is an abnormality in the drive circuit or the semiconductor element Can be detected. That is, it is possible to specify which of the plurality of switch circuits arranged on the same high-frequency line is related to malfunction or failure.

  Further, the switch circuit may be a series circuit type or a shunt circuit type. The series circuit is a circuit having a configuration in which the switch element is connected in series with the high-frequency line center conductor, and the shunt circuit is a circuit having a configuration in which the switch element is connected between the high-frequency line center conductor ground conductors. In an example using a semiconductor element as a switch element, a series circuit is a central conductor of a corresponding high-frequency line so that transmission through the high-frequency line is allowed and blocked when the semiconductor element is conductive. The shunt circuit is connected to the center conductor and the ground conductor of the corresponding high-frequency line so that transmission through the high-frequency line is blocked and blocked when the semiconductor element is conductive. A circuit in which the semiconductor element is inserted between the two. By using semiconductor elements, switching time can be shortened, power fluctuations and phase fluctuations before and after switching and during transient periods can be suppressed, and switching devices can be reduced in size and price. It is suitable for broadcasting stations and relay stations of terrestrial digital television broadcasting systems, as well as facilitating maintenance and maintenance work by improving reliability and isolation, and making it possible to identify malfunctions and failure locations, and enabling daytime maintenance. A switcher can be realized. In terms of shortening the switching time, the bias voltage or current value is temporarily controlled to increase or decrease when the bias of the semiconductor element (for example, PIN diode) in the switch circuit is forward / reversely switched. It is desirable to control in such a direction that the required switching time becomes shorter. A circuit for this purpose may be attached to the drive circuit or provided in the drive circuit.

  In general, if only one series circuit is provided for each high-frequency line, a λ / 4 line for isolation from an input source and an output destination (= an electrical length that is an odd multiple of λ / 4). The same applies to the following: λ: carrier wavelength of a signal propagating through a high-frequency line), and therefore is not subject to band limitation by the λ / 4 line, and is suitable for wideband design. On the other hand, since one of the electrodes of the semiconductor element can be connected to the ground conductor, the shunt circuit that easily releases heat through the connection has better heat dissipation, and therefore for broadcasters that handle high-power high-frequency signals. Suitable for use. When a plurality of switch circuits are provided at the same location, a shunt circuit will be used. At that time, in order to prevent a bias voltage from appearing in the center conductor and the ground conductor of the corresponding high-frequency line, it is desirable to add a capacitor for blocking direct current to the shunt circuit. This capacitor also serves to protect the semiconductor element against lightning surges and other excessive / noise inputs. Also, when using a shunt circuit, it is desirable to provide a λ / 4 line between the shunt circuit and the input source and the output destination to ensure isolation, and furthermore, at different locations on the same high-frequency line. When providing a shunt circuit, a λ / 4 line is also provided between them to ensure isolation between the two.

When the power of the signal to be handled is large, it is desirable to use the low impedance method when using the shunt circuit. The low impedance method proposed by the inventor of the present invention uses a λ / 4 line to suppress the voltage applied to the shunt circuit, in particular, the semiconductor element, thereby increasing the power (high frequency) by a relatively low voltage specification semiconductor element. This is a technique that enables signals to be handled. Specifically, the intrinsic impedance of the first line portion including the location where the shunt circuit is disposed in the high-frequency line is divided into two pieces interposed between the first line portion and the input source side and the output destination side. This is a technique of lowering the specific impedance of the second line portion. The first line portion is a λ / 2 wavelength line (= a line having an electrical length that is a natural number multiple of λ / 2; the same applies hereinafter). Also, suppose that the intrinsic impedance in the second line portion is Z0, and the intrinsic impedance of the first line portion including the location where the shunt circuit is disposed is Z0 / 2. Assuming that the line portion having an impedance of Z0 is loaded, the impedance when the central portion of the first line portion is viewed from one end of the first line portion is Z0 / 4. Compared to the case of a line, the voltage at the center of the first line portion is 1/4 ^1/2 = ^1/2 . Therefore, it is possible to use a low-voltage specification semiconductor element by disposing a shunt circuit in any part of the first line portion. Note that the increase in current due to the voltage drop may be dealt with by parallelizing shunt circuits (semiconductor elements) or increasing the number of parallel shunt circuits. In this case also, it is desirable to provide a drive circuit for each switch circuit.

  Furthermore, a series circuit and a shunt circuit can be mixed and used as a switch circuit in the switch according to the present invention. In that case, preferably, among a plurality of high-frequency lines connected to the same input source or output destination, for any one of the series circuit as a switch circuit, for the remaining high-frequency line, a shunt circuit as a switch circuit, respectively It will be provided. Further, the drive circuit is provided corresponding to the series circuit. The shunt circuit is driven by this drive circuit associated with the series circuit. Therefore, a bias voltage supply path from the drive circuit to the shunt circuit is provided corresponding to the shunt circuit. Thus, a plurality of switch circuits can be driven by a single drive circuit. Furthermore, by providing a capacitor on the input source, output destination, or high-frequency line that cuts the input source and output destination in a DC manner from the drive circuit, the shunt circuit is arranged from the series circuit location of the multiple high-frequency lines. The line portion reaching the location can be made to function as a bias voltage supply path from the drive circuit provided corresponding to the series circuit to the shunt circuit. That is, it is not necessary to add a bias signal line for sharing the drive circuit.

  In providing a shunt circuit, it is desirable to incorporate a countermeasure against abnormal heat generation as a structural device. For example, when a component of a shunt circuit, such as a semiconductor element or a capacitor, generates excessive heat, the shunt circuit is provided with an overheating automatic cutting member that separates the shunt circuit or the generated component from the center conductor of the corresponding high-frequency line. . As the automatic cutting member at the time of overheating, for example, a component such as a thermal fuse can be used. If a component having flexibility or buffering properties such as a thermal fuse is used, it is possible to suitably prevent damage to the shunt circuit when mechanical / thermal stress is applied to the line portion in which the shunt circuit is incorporated. The overheating automatic cutting member is not limited to a component, and may be a member that is not normally recognized as a component, for example, a low melting point solder.

  Furthermore, it is desirable to devise the installation form of the high-frequency line so that the part of the high-frequency line in which the shunt circuit or the like is incorporated can be separated and replaced.

  First, an arbitrary high-frequency line in the switch exists between a switch circuit side line portion provided with one or a plurality of switch circuits, and between the switch circuit side line portion and an input source and an output destination. It is divided into individual terminal-side line portions. The switch circuit side line part is a part of the switch circuit side line part between the terminal circuit line part closest to the terminal side line part and the switch circuit arranged in the switch circuit side line part. The λ / 4 wavelength line portion is configured to be interposed. Thereby, the isolation of the switch circuit (group) with respect to the terminal side line portion is ensured. On the other hand, each terminal-side line portion is a line portion extending from the input source or the output destination by a natural number multiple of λ / 2 wavelength in electrical length. Thereby, the isolation with respect to the input source and output destination of the connection part of a terminal side line part and a switch circuit side line part is ensured. Therefore, even if the switch circuit side line portion is disconnected from the high frequency line as necessary (if the high frequency current is not flowing through the semiconductor element in the switch circuit), the function of the other parts of the switch or the switch This does not affect the operation.

  Utilizing this fact, in a preferred embodiment of the present invention, a U-link is formed as a unit for housing a switch circuit or a drive circuit together with the switch circuit. The U link is a unit obtained by unitizing the switch circuit side line portion described above, and is provided so as to be removable from the terminal side line portion, and has a shape that can be gripped or sandwiched, for example, a shape similar to a handle or a staple. If the high-frequency line is a rigid line, the attaching / detaching operation of the U link is particularly simple and the handling property is excellent. Further, when a shunt circuit is housed as a switch circuit in the U link, a capacitor that cuts off direct current is provided in the shunt circuit, and a bias voltage applied to a semiconductor element in the shunt circuit appears in the U link housing. Therefore, even if the bias voltage is a high voltage, the voltage does not appear on the outer surface of the U-link, so that no trouble or danger occurs in the work. In addition, if a switch is provided on the panel where the U link is disposed, and the switch detects that the U link has been removed from the panel, the bias voltage can be set according to the detection. It can be stopped. Furthermore, it is desirable to prepare an element-free U link when using the switch. The elementless U-link here is a line portion unit that can be attached to the U-link placement panel instead of the U-link but does not have a switch circuit inside. By attaching / detaching the elementless U link to / from the panel, it is possible to perform forced switching manually without depending on the switch circuit, which is useful for emergency operation.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In the following description, an example is shown in which the switch of the present invention is used to implement the two-broadcaster system at a terrestrial television broadcasting station. This is for simplicity of description and does not limit the scope of the present invention. That is, it will be apparent from the following description that the present invention can be applied to a switch that requires high reliability, high quality, low cost, etc., especially a switch that can handle a high-power high-frequency signal. .

(1) Basic Configuration FIG. 1 shows the configuration of a broadcast station switch according to an embodiment of the present invention, FIG. 2 shows the relationship between the configuration of the switch circuit and the drive circuit, and a structural example of a shunt circuit as a switch circuit. FIG. 4 shows an example of a U link, which is a unit including a shunt circuit, in FIG. As shown in FIG. 1, the switch SW according to the present embodiment has inputs 1 and 2 as input terminals for connecting a broadcaster as an input source, and an output for connecting to an output destination such as a transmission antenna ANT. And an output terminal to which a dummy load RD for matching termination / absorption of the output of the broadcaster not connected to the transmission antenna ANT is connected. Four high frequency lines are provided in the switch SW, and two sets of shunt circuits are provided on each high frequency line.

  A high-frequency line connecting the input 1 and the transmission antenna ANT will be described as an example. As shown in FIG. 1, nλ / 2 + 4 / λ (λ: carrier wavelength of the broadcast signal) from the input 1 on the high-frequency line in terms of electrical length. A set of shunt circuits S1 and S2 are provided at a remote location A, and another set of shunt circuits S1 and S2 are provided at a location B that is nλ / 2 + 4 / λ in electrical length from the output terminal to the transmission antenna ANT. A line having an electrical length of λ / 4 is provided between the shunt circuit placement location A and the shunt circuit placement location B. C and D on the high frequency line connecting the input 2 and the dummy load RD, E and F on the high frequency line connecting the input 1 and the dummy load RD, and the high frequency line connecting the input 2 and the transmitting antenna ANT G and H also have the same relationship with the input and output terminals connected by the high-frequency line, and each is provided with a pair of shunt circuits S1 and S2.

  As shown in FIG. 2, the shunt circuits S1 and S2 connect the anodes of the PIN diodes D11 and D12 to the center conductor of the high-frequency line via capacitors C11 and C12, respectively, and connect the cathodes of the PIN diodes D11 and D12 to the high-frequency line. Circuit configuration connected to the ground conductor. Although not shown in FIG. 1, the drive circuits 31 and 32 for driving the PIN diodes D11 and D12 in the shunt circuits S1 and S2 include individual shunt circuits S1 and S2 as shown in FIG. It is provided corresponding to. The drive circuits 31 and 32 apply a bias voltage to the cathodes of the PIN diodes D11 and D12 via the inductors L11 and L12 and C21 and C22 constituting the LPF. The drive circuits 31 and 32 apply a bias voltage to the corresponding PIN diodes D11 and D12 according to a command given from the outside, while the bias voltage actually applied to the PIN diodes D11 and D12 and the flowing current are applied. By monitoring, the occurrence of abnormality in the corresponding shunt circuits S1, S2 including the PIN diodes D11, D12 is detected. The result is appropriately supplied from the drive circuits 31 and 32 to the user or an external device by a notifying means (not shown).

  Further, the shunt circuit specifically adopts a structure shown in FIG. 3, for example. Since FIG. 3 shows a structure for one shunt circuit, it should be noted that the structure shown in FIG. 3 is actually provided for the number of shunt circuits shown in FIG. In the structure shown in FIG. 3, a rigid high-rigidity coaxial cable having a gas-phase dielectric or vacuum interposed between the center conductor and the ground conductor, particularly a ground conductor that is an outer conductor, is a rigid high-frequency line. A coaxial line is assumed. The shunt circuit is housed between a coaxial center conductor 38 that is an inner conductor of the coaxial line and a ground conductor that is an outer conductor of the coaxial line. In FIG. 3 and FIG. 4 to be described later, the location where the shunt circuit, particularly its PIN diode (and in some cases, a part of the drive circuit) is housed is referred to as a diode mounting portion. The grounding conductor forming the above is referred to as a diode mounting portion casing 39.

  In the members shown in FIG. 3, the PIN diode D1 corresponds to those shown as D11 and D12 in FIG. The anode of the PIN diode D1 is connected to the outside of the diode mounting portion via the inductor L1. The inductor L1 corresponds to that shown as L11 and L12 in FIG. The cathode of the diode D1 is connected to the diode mounting unit housing 39 or a conductor (not shown) connected thereto. In addition, a feedthrough capacitor C2 is mounted on the diode mounting portion casing 39, and one end of the inductor L1 is drawn out to a drive circuit outside the diode mounting portion via the center of the feedthrough capacitor C2. That is, the capacitor C2 corresponds to that shown as C21 and C22 in FIG. Further, the capacitor C1 is a member corresponding to those shown as C11 and C12 in FIG. 2, and is connected to the coaxial central conductor 38 at a predetermined shunt circuit location.

  In the structure shown in FIG. 3, a thermal fuse F is further incorporated using a pair of mounting brackets 40. The mounting bracket 40 is a member having good conductivity, one of which is connected to the capacitor C1 and the other is connected to the anode of the diode D1. The thermal fuse F provided between the mounting brackets 40 is made of a conductive material that melts and breaks even at a relatively low temperature. That is, when the shunt circuit components such as the diode D1 or the capacitor C1 generate heat and as a result the temperature of the temperature fuse F reaches a predetermined temperature or more, the temperature fuse F is blown and the connection between the capacitor C1 and the PIN diode D1 is established. Refused. The thermal fuse F is formed of a material having flexibility and buffering properties so that the shunt circuit and its internal and external conductive paths are not damaged even when stress caused by thermal expansion or the like is applied to the diode mounting portion. , Absorb at least part of the deformation due to the stress.

  Furthermore, each high frequency line shown in FIG. 1 is divided into a shunt circuit side line part (U1 to U4) and a terminal side line part which is the other part. A high-frequency line connecting the input 1 and the transmission antenna ANT will be described as an example. A portion sandwiched between two terminal-side line portions, that is, a portion extending from a to A through B in the figure is on the shunt circuit side. It is a track part. A λ / 4 line is provided between the shunt circuit arrangement location A and the shunt circuit arrangement location B for isolation between them, and between the shunt circuit arrangement location A and the point a and the shunt circuit arrangement. Since a λ / 4 line is also provided between the point B and the point b for isolation between them, the electrical length of the shunt circuit side line portion is conveniently 3λ / 4. Further, a portion extending from the input 1 to the point a and a portion extending from the output terminal to the transmission antenna ANT to the point b are terminal side line portions. The electrical length of each terminal side line portion is set to nλ / 2 in order to secure the isolation between the input 1 or the output terminal to the transmitting antenna ANT and the point a or b and to enable or facilitate the removal of the U link. (N is an integer of 1 or more). If it is not necessary to attach and detach the U link, that is, if the U link structure is not adopted, n = 0 may be used.

  As shown in FIG. 4, the U link is a shunt circuit side line portion made of a rigid coaxial line, and a shunt circuit (and a part of the drive circuit) having the structure shown in FIG. This is housed in the diode mounting portions 33 and 34 which are the portions. For example, the U link U1 is a line portion including shunt circuit locations A and B, and both ends thereof correspond to points a and b in FIG. The U link U is a “U” -shaped or “C” -shaped tube similar to a handle or a staple, and is separated from the switch SW side at the end position (a and b in the case of U1). Can be installed. In order to do so, one end of the terminal-side line portion is arranged on the panel 41 of the switch SW as a mounting destination in accordance with the shape and dimensions of the U link U. Further, on the mounting destination panel 41 of the U link U, the contact opens as the U link U moves away from the panel 41, that is, the operator or a predetermined tool / device contacts the U link U and the U link U A micro switch 42 is provided so that it can be detected when the removal work is started.

(2) Advantages As described above, in this embodiment, the PIN diodes D11 and D12 are used as switching elements instead of the mechanical contacts 1 to 4 in the switch SW1 or SW2 of the multiple switch system shown in FIG. The shunt circuits S1 and S2 are provided. Since the semiconductor switch element is used, the time required for switching is shorter than the multiple switch system having mechanical contacts and the crossover system having a mechanism for driving variable capacitors. Depending on the circuit implementation, application, and required specifications, it is possible to realize a high-speed switching device that can be switched in a time of about 1 μsec. Similarly, because there is no mechanical drive unit, power fluctuation and phase fluctuation of the transmission antenna output hardly occur before and after switching and during the transition period, and therefore, synchronization on the receiver side hardly occurs. Furthermore, the use of a PIN diode as a semiconductor element achieves a reduction in size and price, and also enables maintenance opportunities and reduction of maintenance personnel.

  In particular, in the digital terrestrial television broadcasting system, since a guard interval, which is a period during which some data is repeated, is provided in the broadcast signal as a countermeasure against multipath, instantaneous interruption or phase fluctuation within the guard interval length is provided. Can be absorbed in the receiver. Therefore, if a guard interval synchronization switching method is used together, for example, guard interval detection is performed and switching by the switch SW is performed in synchronization with the guard interval timing, the influence of instantaneous interruption or the like can be suitably suppressed. That is, the switch SW according to the present embodiment is a switch suitable for a terrestrial digital television broadcast station or relay station. For guard interval detection and the like, refer to the above-mentioned Patent Document 1 or 2.

  In this embodiment, a shunt circuit is used as the switch circuit. As is apparent from the description of FIG. 2 or FIG. 3, the shunt circuit is a circuit system in which the electrode of the switch element (here, the cathode of the PIN diode) can be connected to the ground conductor. It is easy to dissipate the heat generated in the ground conductor to the ground conductor, and is excellent in heat dissipation. In a switching device that handles a high-power high-frequency signal, such as a switching device for a broadcaster, it is desirable to use a shunt circuit that is excellent in heat dissipation to ensure its stability and reliability. By ensuring the heat dissipation, it is possible to suppress the malfunction / failure of the switch SW, particularly its switch element, and thus the probability / frequency of occurrence of wave breakage / damage.

  In the present embodiment, two shunt circuits S1 and S2 are provided in parallel at the same location on the high-frequency line. Therefore, compared with the embodiment in which only one shunt circuit is provided, the current capacity, the allowable loss, and the like are increased, so that it is possible to handle a larger amount of power and a load sharing (derating) effect is also produced.

  Furthermore, in this embodiment, a pair of shunt circuits is provided at two locations on the same high-frequency line (two-stage connection). Therefore, the isolation between input and output is high. Assuming that N (dB) isolation is obtained in one stage, the isolation increases in accordance with the number of stages, such as 2N (dB) for two stages and 3N (dB) for three stages.・ It is desirable to increase as much as possible within the allowable range of cost. In addition, it is desirable to provide a λ / 4 line between the stages as shown in FIG. 1 to ensure isolation between the two. Further, when examining the content and signal state of the broadcast signal output from the broadcaster connected to the dummy load RD via the switch SW, the broadcast signal output from the broadcaster connected to the transmission antenna ANT If it leaks to the dummy load RD side, it cannot be accurately checked, which is inconvenient. In this embodiment, since the isolation between input and output is good, such troubles are unlikely to occur, and therefore, the inspection (daytime maintenance) of the signal content and signal state during the broadcast time can be suitably performed. There is no need to do it late at night or early in the morning. Moreover, the burden on facilities, such as providing a separate switch for daytime maintenance, is reduced.

  Further, in the present embodiment, drive circuits 31 and 32 are provided individually for each of the shunt circuits S1 and S2. Therefore, even if a short mode failure or breakdown voltage degradation occurs in the shunt circuit S1, a bias voltage is supplied to the shunt circuit S2 from the drive circuit 32 that is a bias voltage source independent of the drive circuit 31. The bias state of the PIN diode D12 in the shunt circuit S2 does not substantially change, and the state of the high-frequency line is maintained in the same state as before. As a result, the effect of improving reliability by redundancy is obtained, and the possibility of wave stopping is reduced.

  Further, each drive circuit in the present embodiment detects the occurrence of an abnormality in the corresponding shunt circuit by monitoring the bias voltage actually applied to the shunt circuit, particularly the PIN diode, and the current flowing. Since the drive circuit is provided corresponding to the shunt circuit, it is possible to know in which shunt circuit the abnormality has occurred depending on which drive circuit has detected the abnormality. Therefore, by integrating the abnormality detection status in each drive circuit, the location where the abnormality has occurred can be specified at least in units of shunt circuits. As a result, it is possible to speed up the response when an abnormality occurs.

  Also, if the PIN diode fails in the short mode during forward bias, the current increases, and if the open mode fails, the current stops flowing, and a current different from that in the normal state flows even in other “halfway” mode failures. If the PIN diode fails in the short mode during reverse bias, the current increases dramatically because the reverse bias power supply is high voltage. If the open mode fails, the current stops flowing, and other "half-way" failures such as breakdown voltage degradation However, a different current flows than normal. Even when the drive circuit fails, the current value is different from the normal value. Therefore, the current value during normal operation is measured or calculated according to whether the bias is forward / reverse, etc., and during actual use, the current flowing through the shunt circuit corresponding to each drive circuit is measured at a predetermined frequency. By comparing the current value obtained as a result and the normal current value obtained in advance in consideration of the bias state, it is possible to determine the failure mode in each drive circuit and to detect the failure of the drive circuit itself. it can. In particular, at that time, it is desirable to take into account temperature changes and variations among products. For example, since the current generally increases as the temperature rises, it is possible to detect a state in which heat generation has progressed without causing a failure. Also, if a short mode failure occurs during reverse bias, the power supply capacity will be insufficient and the voltage will drop, or the protection circuit will operate and the power supply will be cut off. It is effective to monitor the voltage or the power supply state of the drive circuit.

  In the present embodiment, each shunt circuit S1, S2 is connected to the center conductor of the high-frequency line via capacitors C11, C12. The shunt circuits S1 and S2 are highly resistant to lightning surges and the like. Also in this aspect, the reliability is improved.

  Furthermore, in the present embodiment, a thermal fuse F is provided so that the PIN diode D1 and the capacitor C1 are blown when abnormal heat is generated. As a result, the PIN diode D1 or the like that has caused abnormal heat generation can be separated from the high-frequency line, so that the situation such as uncontrollability and, in turn, wave breakage is less likely to occur. By using a flexible and shock-absorbing thermal fuse F, stress due to thermal expansion or the like is absorbed by the thermal fuse F and can be made difficult to break. Instead of the thermal fuse F, low melting point solder or the like can be used.

  Moreover, in this embodiment, each shunt circuit side line part is made into U link. Therefore, if necessary, the U link U can be removed from the panel 41, that is, forcibly disconnected from the terminal side line portion. For this reason, it is possible to suitably cope with a situation in which an abnormality occurs in a control device (not shown) and there is a possibility that the drive of the shunt circuit by each drive circuit may not be performed normally by manual forcible switching by removing the U link. Further, when the start of removal is detected by the micro switch 42, the forward bias power supply is automatically turned off, so that the removal can be performed in a state where the high frequency power is not conducted to the PIN diode. Further, when the start of removal is detected by the micro switch 42, the reverse bias power supply is automatically turned off to stop the broadcaster as much as possible. However, since the bias voltage is cut off by the capacitor C2, a DC voltage does not appear on the outer surface of the U link U (at least a high voltage such as a reverse bias voltage). Broadcasting can be continued without implementation. Furthermore, a switch element such as a PIN diode and a non-element U link that does not incorporate a switch circuit can be prepared, and the switch can be operated without depending on the switch circuit.

(3) Modifications Various modifications can be made to the above-described embodiment. First, in the configuration shown in FIG. 1, one pair of shunt circuits S1 and S2 are provided at two locations on one high-frequency line. However, if isolation is not so necessary, one location may be used, or more If you want to improve the balance, you may have more than two. In addition, two shunt circuits are provided in parallel at one location, but one high-frequency line that does not require redundancy may be provided at one location, or one location if the equipment scale, cost, etc. allow. Three or more may be provided. The simplest configuration is a configuration in which one shunt circuit (shunt circuit S) is provided only at one location on the high-frequency line as shown in FIG. 5, and this is appropriately multistaged according to the required isolation and reliability. And parallelization. Further, when the switch circuit side line portion is not separated, such as U-link, n = 0 can be set.

  In the above-described embodiment, a PIN diode is used as a semiconductor switch element. Although a transistor such as MESFET can be used as the switching element, it is desirable to use a PIN diode particularly when a high power signal is handled. The direction of the PIN diode may be opposite to that shown in FIG. 2, but in this case, the polarity of the bias voltage is also reversed. The same applies to NIP diodes.

  Furthermore, in order to make the PIN diode high impedance at a high frequency, it is necessary to apply a sufficient reverse bias voltage. That is, if high frequency power is applied in a state where a sufficient reverse bias voltage is not applied, problems such as spurious generation occur. For this reason, it is desirable to take measures to make the power supply redundant, such as supplying power to each drive circuit from both of the two broadcasters so that the power supply of the drive circuit is not cut off. As a result, a PIN diode type switch that is unlikely to generate spurious or the like can be realized. In order to use a PIN diode in a switch that handles high power, it is necessary to use a sufficiently high-voltage power supply as a reverse bias power supply. However, the high-voltage power supply has a higher impedance than the low-voltage power supply, so the switching time is shortened. The effect may be impaired. Considering this point, when switching to the reverse bias, it is desirable to perform multi-stage power switching to ensure the effect of shortening the required switching time, which is one of the effects of the semiconductor switch.

  In order to further reduce the time required for switching by the PIN diode, the bias voltage or current may be temporarily increased or decreased during a very short period including the switching moment. For example, it is assumed that the drive circuits 31 and 32 (and 35 to 37 in the modifications described later) are configured as shown in FIG. In this circuit configuration, when the semiconductor switch S11 in the drive circuit is turned on, the positive power supply 44 is connected to the PIN diode side, and when the semiconductor switch S21 is turned on, the negative power supply 45 is connected to the PIN diode side. The positive power supply 44 supplies / applies a forward bias current, and the negative power supply 45 supplies / applies a reverse bias voltage to the PIN diode side. The control circuit 43 is a circuit attached to or part of the drive circuits 31 and 32. The control circuit 43 includes control electrodes of the semiconductor switches S1 and S2 through the bias circuit 46 or 47 (in the figure, FETs are used as semiconductor switches). Therefore, by applying a control voltage to the gate), the semiconductor switches S11 and S21 are selectively turned on / off. In order to shorten the time required for switching, the control circuit 43 executes a procedure for temporarily changing either or both of the forward bias current and the reverse bias voltage under the control of the positive power supply 44 and the negative power supply 45. In the example shown in FIG. 14, the control circuit 43 temporarily reduces the forward bias current from, for example, 0.5 A to 0.25 A and switches the reverse bias voltage from −500 V to −400 V when switching from forward to reverse (100). (102). Conversely, when switching from reverse to forward (100), the forward bias current is temporarily increased from 0.5 A to 1 A, for example, or the reverse bias voltage is temporarily increased from, for example, -500 V to -400 V (104). . When the bias state is stabilized after switching or when a sufficient time has elapsed, the control circuit 43 restores the bias state temporarily changed to the normal bias state (106). By executing such a procedure, it is possible to obtain an effect such as shortening of the switching time and thus reduction of missing data bits, reduction of PIN diode heat generation or power consumption, and realization of high power switching. See also Non-Patent Document 3. The procedure shown in FIG. 14 is based on the circuit shown in FIG. 13, and thus the forward bias current is positive and the reverse bias voltage is negative. However, these polarities are inverted depending on the design. In addition, by using this power control function, it is possible to execute control in which the power on the non-use side is suspended during normal times. In addition, although an example in which one positive power supply 44 and one negative power supply 45 are provided has been described, the above procedure or a procedure similar thereto is executed even in a circuit provided with a larger number of power supplies to shorten the time required for switching. can do.

  Further, as shown in FIG. 6, a back-to-back connection in which two PIN diodes D11a and D11b are connected in opposite directions may be employed. This makes it possible to reduce the necessary reverse bias voltage, reduce distortion, and the like. Since there are two diodes, two inductors (L11a and L11b) corresponding to the inductor L11 in FIG. 2 are provided in FIG.

  Furthermore, although the shunt circuit is used as the switch circuit in the above-described embodiment, a part or all of the switch circuits may be a series circuit (see also Patent Document 3). FIG. 7 shows an example in which one series circuit R1 to R4 is provided on each high-frequency line. The series circuit is suitable for low power rather than high power because the circuit is stopped when the bias power supply is stopped and is inferior to the shunt circuit in terms of heat dissipation. On the other hand, as shown in this figure, if the number of stages is one, a λ / 4 line is not required. Therefore, if a series circuit is used, a wider-band switch can be realized. The series circuit can be realized by the circuit shown in FIG. In FIG. 8, a PIN diode D2 is inserted in series on the central conductor of the high-frequency line, and capacitors C4 and C5 and an inductor L3 for blocking the bias voltage are provided before and after the PIN diode D2. In response to the command, the drive circuit 35 supplies a bias voltage to the PIN diode D2 via the capacitor C3 and the inductor L2.

  The example shown in FIG. 9 is an example in which a shunt circuit and a series circuit are mixed. A PIN diode D1a as a shunt circuit is at a point α on the high-frequency line from the input 1 to the transmitting antenna ANT side, and a PIN diode D1b as a shunt circuit is at a point β on the high-frequency line from the input 2 to the dummy load RD side. Each is provided. Points α and β are located at a distance of λ / 4 in electrical length from the nearest input / output terminal. Further, a PIN diode D2a, which is a part of the series circuit, is provided at a point γ on the high frequency line from the input 2 to the transmitting antenna ANT side, and a series circuit is provided at a point δ on the high frequency line from the input 1 to the dummy load RD side. Are respectively provided with PIN diodes D2b.

  Two drive circuits (36 and 37) are provided, and the bias voltage output from the drive circuit 36 is supplied to the PIN diode D2a via the capacitor C3a and the inductor L2a, and further to the PIN diode D1a via a part of the high-frequency line. Has been supplied to. Similarly, the bias voltage output from the drive circuit 37 is supplied to the PIN diode D2b via the capacitor C3b and the inductor L2b, and further to the PIN diode D1b via a part of the high frequency line. In order to cut off the bias voltage, a capacitor C4a or C4b is provided on the side opposite to the PIN diode D2a or D2b of the series circuit when viewed from the points γ and δ, and a capacitor C6 is provided at each terminal. In this configuration, the number of drive circuits is reduced, the signal line for applying the bias voltage is saved, and when the bias power supply is stopped, the input 1 is automatically set to the transmission antenna ANT and the input 2 is automatically set to the dummy load RD. Since it is connected, it is possible to prevent the occurrence of an indeterminate state due to the power interruption. It is also possible to improve isolation by providing each switch circuit in multiple stages.

  Furthermore, it can be said that the above-described embodiment is an application / improvement example of the present invention to the switch SW1 or SW2 in the prior art shown in FIG. However, the present invention can be applied to the prior art shown in FIG. 12, for example, the phase shifter can be a PIN diode type phase shifter, and measures such as redundancy can be applied as in the present invention. Further, both of FIG. 11 and FIG. 12 have a mode in which the outputs of the two broadcasters are combined and transmitted. Such a mode can be realized by using the switch SW according to the above-described embodiment and referring to the disclosure by the literature listed above.

In addition, the low impedance method can be applied to each high-frequency line in the switch SW, particularly to a portion near the shunt circuit. Considering a configuration in which only one shunt circuit is provided on one high-frequency line for simplicity, in the low impedance method, as shown in FIG. 10A, for example, the intrinsic impedance of the λ / 4 line before and after the shunt circuit S Is Z0 / 2, for example, 1/2 of the intrinsic impedance Z0 of the other part. As shown in FIG. 10B, the impedance when the output side is viewed from the connection point between the high-frequency line and the shunt circuit is the impedance when the λ / 4 line having the intrinsic impedance Z0 / 2 is terminated with the impedance Z0. Therefore, Z0 / 4 is obtained according to a known law. Further, as shown in FIG. 10 (c), the impedance when the connection point is viewed from a position away from the input side by λ / 4 as viewed from the connection point is the λ / 4 line having the intrinsic impedance Z0 / 2. Since it is the impedance when terminated with the impedance Z0 / 4, it becomes Z0 according to a known law. Therefore, as shown in FIG. 10 (d), the impedance when looking at the position separated from the input side by λ / 4 from the connection point to the output side by λ / 4 as viewed from the connection point is Z0. Does not occur. Focusing on the high-frequency voltage appearing at the connection point, since the impedance is reduced to Z0 / 4, from the formula of V = (PZ) ^1/2 , it is reduced to 1/2 times compared to when the low impedance method is not applied. You can see that

  Therefore, it is possible to use a semiconductor element (PIN diode) having a lower voltage specification by applying the low impedance method. The increase in current due to the voltage drop may be compensated by increasing the number of parallel semiconductor elements. High-voltage compatible semiconductor elements may be expensive and difficult to obtain, but low-voltage semiconductor elements are inexpensive and generally easy to obtain, increasing the number of parallel semiconductor elements and thus increasing costs. Complementary cost reduction effect can be obtained. As a result, a switch for high power can be realized at a lower cost, and parts procurement can be speeded up. Further, in FIG. 10, the connection point is located at the center of the λ / 2 line, but it is not necessary to be strictly at the center.

  The present invention can be applied to various types of switching devices including a switching device for digital terrestrial television broadcasting.

It is a circuit diagram which shows the structure of the switch concerning one Embodiment of this invention. It is a circuit diagram which shows the structure of the switch circuit in this embodiment. It is a figure which shows the structure of the shunt circuit in this embodiment. It is a side view which shows the external appearance of the U link in this embodiment. It is a partial circuit diagram which shows the modification of this embodiment. It is a figure which shows the modification of the switch circuit in this embodiment one each in (a) and (b). It is a circuit diagram which shows the structure of the modification of the switch which concerns on this embodiment. It is a circuit diagram which shows the structure of the switch circuit in the modification. It is a circuit diagram which shows the structure of the switch concerning another modification. It is a figure which shows the example of the high frequency line in another modification, (a) is a figure which shows a circuit structure, (b)-(d) is a figure which respectively shows the synthetic | combination principle of a high frequency line. It is a circuit diagram which shows the structure of the switch concerning a prior art. It is a block diagram which shows the structure of the other switch concerning a prior art. It is a figure which shows an example of the drive circuit in suitable embodiment of this invention. It is a flowchart which shows the switch required time shortening procedure by bias power supply control.

Explanation of symbols

  31, 32, 35 to 37 Drive circuit, 33 and 34 Diode mounting part, 43 Control circuit, 44 Positive power supply, 45 Negative power supply, a to h U link end position, A to H, α, β Shunt circuit location ANT transmitting antenna, C1 to C6, C11, C12, C21, C22, C3a, C3b, C4a, C4b capacitor, D1, D1a, D1b, D11, D11a, D11b, D12, D2, D2a, D2b PIN diode, F temperature Fuse, L1-L3, L11, L11a, L11b, L12, L2a, L2b Inductor, R1-R4 series circuit, RD dummy load, S, S1, S2 shunt circuit, S11, S21 Semiconductor switch, SW switch, U, U1 ~ U4 U link, Z0 intrinsic impedance, γ, δ series circuit location, Wavelength.

Claims (6)

A switch for selectively connecting any one of a plurality of input sources to a predetermined output destination,
A plurality of high-frequency lines that connect each input source and output destination in high frequency, a switch circuit provided for each high-frequency line to selectively block the high-frequency connection, and a drive circuit that drives the switch circuit; In a switching device comprising:
The switch circuit includes a semiconductor element that conducts / cuts off according to a bias voltage,
The drive circuit is a circuit that applies a bias voltage to the semiconductor element in the corresponding switch circuit,
The semiconductor is connected between the center conductor and the ground conductor of the corresponding high-frequency line so that at least one of the switch circuits is permitted when transmission through the high-frequency line is blocked when the semiconductor element is conductive. It is a shunt circuit with an element inserted,
Among the high-frequency lines, a line portion including the arrangement location of the shunt circuit and having an electrical length (λ: a carrier wavelength of a signal propagating through the high-frequency line) that is a natural number multiple of λ / 2 across the input source side and the output destination side is A switching device characterized by being a line portion having a low intrinsic impedance with respect to a line portion on an input source side and an output destination side when viewed from the line portion. The switch according to claim 1,
A plurality of switch circuits are provided for at least one of the plurality of high-frequency lines,
A switching device characterized in that a drive circuit is provided for each switch circuit. The switch according to claim 1,
The semiconductor element in the switch circuit is a semiconductor element that is turned on / off by forward / reverse switching of the bias, and
When switching the bias of the semiconductor element from forward bias to reverse bias, means for temporarily reducing the value of the forward bias current is provided in the drive circuit or provided in the drive circuit so that the time required for switching is shortened. A switching device characterized by that. The switch according to claim 1,
The semiconductor element in the switch circuit is a semiconductor element that is turned on / off by forward / reverse switching of the bias, and
When switching the bias of the semiconductor element from reverse bias to forward bias, means for temporarily reducing the value of the reverse bias voltage is provided in the drive circuit or provided in the drive circuit so as to shorten the time required for switching. A switching device characterized by that. A switch for selectively connecting any one of a plurality of input sources to a predetermined output destination,
A plurality of high-frequency lines that connect each input source and output destination in high frequency, a switch circuit provided for each high-frequency line to selectively block the high-frequency connection, and a drive circuit that drives the switch circuit; In a switching device comprising:
Each switch circuit includes a semiconductor element that conducts / cuts off according to a bias voltage,
The drive circuit is a circuit that applies a bias voltage to the semiconductor element in the corresponding switch circuit,
At least one of the switch circuits has a semiconductor element inserted in the center conductor of the corresponding high-frequency line so that transmission through the high-frequency line is allowed and blocked when the semiconductor element is conductive A series circuit, between which the other switch circuit is allowed between the center conductor and the ground conductor of the corresponding high-frequency line so that transmission through the high-frequency line is blocked and blocked when the semiconductor element is conductive. A shunt circuit in which the semiconductor element is inserted;
A series circuit is provided as a switch circuit for any of a plurality of high-frequency lines connected to the same input source or output destination, and a shunt circuit is provided as a switch circuit for the remaining high-frequency lines,
While providing a drive circuit corresponding to the series circuit, a bias voltage supply path from the drive circuit to the shunt circuit is provided corresponding to the shunt circuit,
By providing capacitors on the input source, output destination, or high-frequency line that cut off the input source and output destination in direct current with respect to the drive circuit, from the series circuit location to the shunt circuit location in the multiple high-frequency lines. The line part that reaches is made to function as a bias voltage supply path from the drive circuit provided corresponding to the series circuit to the shunt circuit,
The semiconductor element in the switch circuit is a semiconductor element that is turned on / off by forward / reverse switching of the bias, and
When switching the bias of the semiconductor element from forward bias to reverse bias, means for temporarily reducing the value of the forward bias current is provided in the drive circuit or provided in the drive circuit so that the time required for switching is shortened. A switching device characterized by that. A switch for selectively connecting any one of a plurality of input sources to a predetermined output destination,
A plurality of high-frequency lines that connect each input source and output destination in high frequency, a switch circuit provided for each high-frequency line to selectively block the high-frequency connection, and a drive circuit that drives the switch circuit; In a switching device comprising:
Each switch circuit includes a semiconductor element that conducts / cuts off according to a bias voltage,
The drive circuit is a circuit that applies a bias voltage to the semiconductor element in the corresponding switch circuit,
At least one of the switch circuits has a semiconductor element inserted in the center conductor of the corresponding high-frequency line so that transmission through the high-frequency line is allowed and blocked when the semiconductor element is conductive A series circuit, between which the other switch circuit is allowed between the center conductor and the ground conductor of the corresponding high-frequency line so that transmission through the high-frequency line is blocked and blocked when the semiconductor element is conductive. A shunt circuit in which the semiconductor element is inserted;
A series circuit is provided as a switch circuit for any of a plurality of high-frequency lines connected to the same input source or output destination, and a shunt circuit is provided as a switch circuit for the remaining high-frequency lines,
While providing a drive circuit corresponding to the series circuit, a bias voltage supply path from the drive circuit to the shunt circuit is provided corresponding to the shunt circuit,
By providing capacitors on the input source, output destination, or high-frequency line that cut off the input source and output destination in direct current with respect to the drive circuit, from the series circuit location to the shunt circuit location in the multiple high-frequency lines. The line part that reaches is made to function as a bias voltage supply path from the drive circuit provided corresponding to the series circuit to the shunt circuit,
The semiconductor element in the switch circuit is a semiconductor element that is turned on / off by forward / reverse switching of the bias, and
When switching the bias of the semiconductor element from reverse bias to forward bias, means for temporarily reducing the value of the reverse bias voltage is provided in the drive circuit or provided in the drive circuit so as to shorten the time required for switching. A switching device characterized by that.

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