Abstract: A frequency-characteristics variable filter, a duplexer, and a communication apparatus that can be operated at reduced bias voltages that are applied to diodes provided for switching frequency characteristics without reducing the stability of frequency characteristics and without increasing the occurrence of skews. Also, the single duplexer can be used for two frequency bands. As a diode for each of resonators in a transmitting filter and the first resonator in a receiving resonator, a diode having an interterminal electrostatic capacitance in the off state smaller than that of a diode used for other resonators is used. Also, the diodes for the resonators excluding the first resonator in the receiving filter has a lower forward resistance in the on state and an Q value in the off state higher than those of other diodes.

Abstract: A wireless LAN RF module uses parasitic element compensation devices in an antenna select circuit to improve port isolation. In addition, various combinations of RC filter networks and spurious radiation attenuators are incorporated into the Quad Demod/Mod and Synthesizer ;/circuits to provide suppression of EMI susceptibility and radiation throughout the RF module.

Abstract: A diplexer employed in mobile communications equipment such mobile phones which can divide signals into two channels with a simple configuration without interfering the other band. In this diplexer, an inductor 105 is connected between a &pgr;-type three-stage one polar low-pass filter 115 and a common terminal 113 as a first matching circuit, and a capacitor 106A is connected between a one polar band-pass filter 116 and a common terminal 113 as a second matching circuit so that interference with the other band can be prevented and the higher harmonics can be sufficiently attenuated with simple configuration.

Abstract: A method is presented for biasing an attenuator circuit used in high frequency applications. The method can improve the stability of the AGC system, and in some cases also the control accuracy. An attenuator circuit is disclosed which comprises at least two attenuator members (23) connected in series. In connection with the attenuator members (23) in an attenuator circuit according to the invention there are connected a suitable number of biasing members (22) with which the biasing currents of the attenuator members (23) can be controlled to have different magnitudes, so that in an attenuation situation the attenuator members (23) begin to conduct separately, controlled by the AGC circuit.

Abstract: The microwave DPDT switch according to the present invention is composed of (1) a branch line coupler having three gaps at the branch lines among two input ports and two output ports, and (2) three SPST switches locating at the three branch line gaps to transmit input signals to the output ports.

Abstract: The present invention relates to a printed circuit board of the present invention comprising: a main transmission line; and additional transmission lines positioned on both sides of the main transmission line and parallel-connected to the main transmission line by way of selectors.

Abstract: A device for decreasing the number of antennas on a combat vehicle that accommodates several communications terminals has a combiner-separator module for coupling each pair of communications terminals to the same antenna. Each module has one master gate for connecting the antenna and two slave gates for connecting the communications terminals, coupled by way of a transformer stage. The gates are direct-current decoupled from the transformer stage and the master gate is connected to each slave gate by way of a bypass that transmits only a direct current and provides an antenna voltage.

Abstract: There is provided a frequency-variable-type filter, comprising: a voltage control terminal; at least one resonator; a switching device for being switched on/off by a control voltage supplied to the voltage control terminal; and the switching device being in the off-state, when a control circuit as an external circuit which is electrically connected to the voltage control terminal has high impedance at 0 V.

Abstract: A high-frequency switch having a greatly reduced occurrence of high harmonic signals includes first and second switches, and each of these two switches includes two diodes and two transmission lines. Besides, one of the two voltage control terminals is connected, via a resistor, to the intermediate connection point between the anode of one of the two diodes of the first switch and one of the two transmission lines of the first switch. The other of the voltage control terminals is connected, via another resistor, to the intermediate connection point between the anode of one of the two diodes of the second switch and one of the two transmission lines of the second switch.

Abstract: An antenna-duplexer and communication apparatus in which relative phase distortion of transmitted waves and intrusive waves is low, and which are small-scale. An antenna-duplexer comprises a transmission side circuit, electrically connected between a transmission terminal and an antenna terminal, and a reception side circuit, electrically connected between a reception terminal and the antenna terminal. Two PIN diodes, which are connected in series, are connected only to a resonator of the transmission side circuit which is electrically connected closest to the antenna terminal, and a voltage control terminal is connected to the anodes of the PIN diodes, thereby dividing the high-frequency voltage. One PIN diode is connected to each of the other resonators.

Abstract: A multilayer ceramic integrated circuit module for a receiver front-end of a wireless communication device is provided. The module contains an embedded component portion, which has a plurality of thick film capacitors; a plurality of multilayer capacitors; and a plurality of transmission lines deposited internal to the multilayer ceramic integrated circuit module to interconnect the plurality of thick film capacitors and the plurality of multilayer capacitors. The module also contains a mounted component portion, which has a pair of pin diodes; a transistor and a plurality of resistors coupled thereto, for controlling the bias of the pair of pin diodes; and a low-noise-amplifier. The module reduces the size and weight of wireless devices and combines multiple functions into a highly integrated device.

Abstract: An SPST switch having a small transmission loss and a small power consumption is provided. The drain and the source of an FET are connected to each other in series through an induction element and a capacitor element, one terminal of the capacitor element is connected to a first terminal, the other terminal is connected to a second terminal, the gate of the FET is connected to a control terminal, the capacitance of the capacitor element is made equal to the OFF capacitance of the FET, and the inductance of the induction element is set to be such a value that the induction element resonates at a signal frequency with the capacitor element.

Abstract: A fully monolithic cross-point switch matrix overcomes the isolation problems between unconnected ports of the prior art. An Isolation Enhancement Network (IEN) is connected between each of the input and output transmission lines at each of the cross-points. The switch matrix is comprised of a tiled interconnection of M×N of the 1×1 switch/IEN (SIEN) cells, where N and M are the number of input and output ports respectively. Each of the SIEN cells can be independently configured into one of two operating modes, connected or unconnected. The switching element is configured to provide a high isolation path between the input and output lines in the unconnected mode of operation. In this case, a small fraction of the input signal injected at the input port appears at the output port. This output signal is comprised of two components.

Abstract: The invention relates to a switch matrix having n inlets and p outlets, p being greater n. The matrix includes a plurality of switch members each having one inlet and at least two outlets and each enabling a signal applied to the inlet of said member to be transferred to one of the outlets. Each inlet of the matrix being for connection to one out of r outlets. The switch members are of the electronic type and are mounted in such as manner that when switching is performed consisting in modifying a connection from an inlet of the matrix to an outlet thereof, so that said same inlet is connected to another outlet of the matrix, the losses due to the switch members passed through remain substantially the same value. The invention applies to a matrix enabling a faulty electronic element connected to an outlet of the matrix to be replaced by another element connected to another outlet of the matrix.

Abstract: The specification relates to a radio frequency (RF) multiport, multiband semiconductor and transmission circuit. Each port in the multiport circuit is linked to a second port utilizing a semiconductor switching leg. A semiconductor switching leg is biased to either transport thereover an RF signal or to prevent its transport. In an embodiment of the present invention utilizing diodes as an active device within each semiconductor switching leg, a DC biasing signal is applied through an inlet and outlet inductor, thus allowing DC current to pass through the diode for biasing, but preventing RF signal loss to ground. Capacitors are used for RF signal coupling and DC blocking. One embodiment of the present invention is utilized with a dual band cellular/PCS device, with either band selectable for transmission and reception over either an internal antenna or, in the alternative, an external antenna port.

Abstract: A coaxial relay is build up from a contact block and an electromagnet block. The contact block carries a plurality of coaxial connectors each composed of a core conductor and a shield conductor surrounding the core conductor. The core conductors extend into a shield chamber to define thereat respective coaxial contacts. At least one movable blade is disposed within the shield chamber for closing and opening the two adjacent coaxial contacts. The movable blade is provided with a dielectric actuator which projects on the top of the contact block and is engaged with a return spring secured to the contact block for urging the movable blade in a direction of opening the coaxial contacts. The electromagnet block carries at least one electromagnet and an armature which is engageable with the actuator when the electromagnet block is assembled to the contact block. The armature moves about a pivot axis from a first position of opening the coaxial contacts to a second position of closing the same.

Abstract: A compact “T” switch for use in a waveguide communication system switch includes a housing, a rotor, and a motor. The housing includes a pair of ends and an interconnecting sidewall enclosing a cylindrical cavity. One of the housing ends including an entry port, and the sidewall includes a plurality circumferentially spaced exit ports. The rotor is rotatably disposed within the housing cylindrical cavity, and includes an input end having an input port aligned with the housing entry port and an outer surface having a plurality of output ports for alignment with the housing exit ports. The rotor includes a primary or first passage connecting the input port to one of the output ports and further includes at least one secondary passages connecting a pair of the output ports.

Abstract: An antenna switch circuit which suppresses production of a cross modulation distortion includes an input terminal and an output terminal, a field effect transistor connected at a first one of a source electrode and a drain electrode thereof to the input terminal and connected at a second one of the source electrode and the drain electrode to the output terminal, a first controlling power supply to which the drain electrode and the source electrode of the field effect transistor are connected through first and second biasing elements, respectively, a second controlling power supply to which a gate electrode of the field effect transistor is connected through a third biasing element, and a phase shifting element and a feedback resistor connected in series between the second electrode and the gate electrode of the field effect transistor. The field effect transistor is controlled between on and off by varying a voltage of at least one of the first and second controlling power supplies.

Abstract: A switch structure having a base surface; a first high density interconnect (HDI) plastic interconnect layer overlying the base surface layer; a cavity within the HDI plastic interconnect layer; at least one patterned shape memory alloy (SMA) layer overlying the HDI plastic interconnect layer and the cavity, and at least one patterned conductive layer over the at least one patterned SMA layer; a fixed contact pad within the cavity and attached to the base surface and a movable contact pad attached to a portion of the first patterned SMA layer within the cavity such that when the first and second patterned SMA layers and the first and second patterned metallized layers are in a first stable position, the movable contact pad touches the fixed contact pad, thereby providing an electrical connection and forming a closed switch. The structure has a second stable position in which the SMA and metallized layers are flexed away from the cavity so that the contact pads are not in contact and form an open switch.

Abstract: In order to minimize the chip area and improve the linear characteristics obtained when large signals are inputted, a high frequency switch device comprises first, second and third terminals (3, 4, 6); a first circuit composed of a first FET (11), and a first inductor (21) and a first capacitor (25) both connected with the first FET (11) in parallel to each other, one end of the first circuit being connected to the first terminal (3); and a second circuit composed of a second FET (12), and a second inductor (22) and a second capacitor (26) both connected with the second FET (12) in parallel to each other, one end of the second circuit being connected to the first circuit and the other end of the second circuit being connected to the second terminal (4).

Abstract: Disclosed is a switching circuit which has: at least one unit circuit connected in series, the unit circuit being composed of two field-effect transistors connected in series and an inductor that has one end connected to a connection point between the two field-effect transistors and another end grounded; wherein the gates of the two field-effect transistors are commonly connected and a bias voltage to control the turning on/off of the two field-effect transistors is equally applied through a resistance to the respective gates.

Abstract: This invention concerns a multi-port switching circuit which may operate at frequencies up to and even beyond 100 GHz. The invention may be implemented as a GaAs based monolithic microwave integrated circuit. The circuit comprises at least three ports arranged in a star configuration around a central ring. A single switching device is associated with each port. Each switching device is connected to two transmission lines to provide impedance matching and an interconnecting path around the ring. The transmission lines are initially chosen to have a length of a quarter wavelength at the center of the band of operation of the switch. The matching lines and the lines which form the interconnecting ring are then subject to an optimization procedures in which each pair of the switching devices is in turn modeled in their ON state which the remainder of the switching devices is modeled in their OFF state. The optimization procedure aims to achieve low transmission and insertion loss, while provide good isolation.

Abstract: A high-frequency switch in which insertion losses can be reduced and a wiring pattern for supplying control voltages can be simplified. The high-frequency switch has first through fourth ports. A transmission line is connected between each pair of the ports, thereby connecting the pairs of ports to each other. A respective capacitor is coupled between each of the ports and a corresponding one of the nodes between the respective transmission lines. A diode is connected between each of said nodes and a reference potential. A capacitor is coupled between the reference potential and each of the diodes. First through fourth control voltage terminals are connected to respective nodes between each of the diodes and the corresponding capacitors.

Abstract: A duplexer circuit apparatus includes (a) a transmission arm circuit including a first switching circuit which is connected between a transmitter and an antenna, is turned on during transmission, and is turned off during reception, and (b) a reception arm circuit including a second switching circuit which is connected between a receiver and the antenna, is turned off during transmission, and is turned on during reception. In the duplexer circuit apparatus, either the transmitter or the receiver is selectively connected to the antenna, and the transmission arm circuit further includes a cascode amplifier, and an impedance matching inductor connected between the cascode amplifier and the antenna. In this case, the cascode amplifier may be replaced by a source-grounded amplifier constituted by only the FET.

Abstract: Disclosed is a semiconductor switch which has: a first resonance circuit which is composed so that a variable capacitance element and an inductor are in series connected and a series circuit composed of an inductor and a capacitor are in parallel connected to the variable capacitance element and the inductor, the first resonance circuit having one end connected to an input terminal and the other end connected to a first output terminal; a second resonance circuit which is composed like the first resonance circuit and is grounded to the first output terminal; a third resonance circuit which is composed like the first resonance circuit and is connected to the input terminal in parallel with the first resonance circuit, the third resonance circuit having a second output terminal on the reverse side of the input terminal; and a fourth resonance circuit which is composed like the first resonance circuit and is grounded to the second output terminal.

Abstract: An antenna switch for selectively connecting an output differential signal pair of an output power amplifier to a single-ended signal of an antenna when transmitting and selectively connecting an input differential signal pair of a low noise input amplifier to the single-ended signal of the antenna when receiving. A first balun having a single ended-signal connected to an antenna connects a first and second output differential signal to a power output amplifier. A second balun having a single-ended signal connected to the antenna connects a first and second input differential signal to a low noise input amplifier. A first diode selectively shorts the first output differential signal to the second output differential signal of the first balun when receiving and a second diode selectively shorts the first input differential signal to the second input differential signal of the second balun when transmitting.

Abstract: A composite high-frequency component is designed to occupy a smaller area and a smaller volume when mounted in an apparatus, can be located in the apparatus with improved flexibility, and is able to operate without an impedance matching circuit. The composite high-frequency component includes a multilayer substrate, diodes constituting a high-frequency switch component, and a circuit base. External terminals for connection to a transmitting circuit, a receiving circuit and an antenna, external terminals for control and an external terminal for connection to ground potential are formed on an outer surface of the multilayer substrate. Strip lines and capacitors constituting the high-frequency switch and strip lines and capacitors constituting a low-pass filter circuit are formed in the multilayer substrate.

Abstract: A switching device is disclosed having a ring circuit with four nodes and four switching elements which selectively interconnect the four nodes. A first compensation branch inter-connects a first pair of mutually opposing nodes, and a second compensation branch inter-connects a second pair of mutually opposing nodes. The first compensation branch generates a first parallel resonance in conjunction with a first non-conducting one of the four switching elements, and the second compensation branch generates a second parallel resonance in conjunction with a second non-conducting one of the four switching elements. The first parallel resonance is connected in parallel to a conducting one of the four switching elements, and the second parallel resonance is connected in parallel to the conducting one of the four switching elements. Each compensation branch includes an inductor which forms the respective parallel resonances in conjunction with a capacitance of a non-conducting switching element.

Abstract: In a switching circuit, low insertion loss and enough isolation can be ensured at a desired frequency at the same time. An inductor is externally connected in parallel with the path between the drain and source of each of field-effect transistors built in a switching integrated circuit, and the inductor and the OFF capacitance of the field-effect transistor are made to generate parallel resonance. At this time, by suitably adjusting the inductance, low insertion loss and enough isolation are ensured at a desired frequency at the same time.

Abstract: An apparatus includes a first mixer port (12), a second mixer port (14), a third mixer port (16), a first hybrid device (20) responsive to the first mixer port (12) and having a first and a second input/output port, a second hybrid device (40)responsive to the second mixer port (14), the third mixer port (16) responsive to the second hybrid device (40), and a switching device (30). The switching device (30) includes a first port (31) responsive to the first input/output port of the first hybrid device (20), a second port (32) responsive to the second port of the first hybrid device (20),a third port (34) in communication with the second hybrid device (40), a fourth port (36) in communication with the second hybrid device (40), and a switching element responsive to the first, second, third, and fourth ports (31, 32, 36, 34). The switching element includes a first field effect transistor (60) and a second field effect transistor (62).

Abstract: A first FET is connected between first and third nodes, a second FET is connected between second and fourth nodes, a third FET is connected between third and fifth nodes and a fourth FET is connected between fourth and fifth nodes. A fifth FET is connected between first and sixth nodes and a sixth FET is connected between second and sixth nodes. The gates of the first, fourth and sixth FETs are connected to a first control terminal and the gates of the second, third and fifth FETs are connected to a second control terminal. A power-supply terminal is connected to the fifth and sixth nodes. The first and second nodes are connected to a common terminal through first and second capacitors, respectively. The fifth and sixth FETs form a pull-up switching circuit. The pull-up switching circuit pulls up the source of an FET in an OFF state to the power-supply voltage and isolates the source of an FET in an ON state from the power-supply voltage.

Abstract: An antenna switch comprises a first switch device (11) for selectively coupling a common point (e) with a transmit terminal (a) or a receive terminal (c), a second switch device (12) having similar structure to the first switch device (11) for selectively coupling a common point (f) with a first antenna terminal (b) or a second antenna terminal (d), and a filter (13) coupled between the switch devices (11, 12) through capacitors (14, 15). Circuit structure of the first switch device (11) is the same as that of the second switch device (12). Components composing those switch devices are mounted on each layer of a multi-layer substrate with a symmetrical relationship. The number of components is small, and the structure of an antenna switch is simplified. It is used in a portable telephone set for switching transmit/receive operation, and switching antennas.

Abstract: Switches are provided on the input and output side of an amplification stage in a signal switching circuit provided in a signal transmission line, and another signal is provided so that a signal can be transmitted directly. Further, a switching circuit is formed from FET elements, which are controlled to be switched on/off by control signals to assure a high isolation.

Abstract: A transmit/receive switch includes a first quarter-wavelength transmission line coupled between an antenna port and a first variable impedance device. The first variable impedance device is coupled between the first quarter-wavelength transmission line and a signal common node. An impedance of the first variable impedance device is controllable variable between a low impedance value and a high impedance value. A second quarter-wavelength transmission line is coupled between first variable impedance device and a first port. A third quarter-wavelength transmission line is coupled between the antenna port and a second variable impedance device. The second variable impedance device is coupled between the third quarter-wavelength transmission line and the signal common node. Like the first variable impedance device, an impedance of the second variable impedance device is controllable variable between a low impedance value and a high impedance value.

Abstract: A quantum wire switch and a switching method for switching charge carriers between a first output and a second output utilizing quantum interference of the charge carriers. A quantum switch includes a quantum wire extending from an input to a first output, a second quantum wire extending from the input to a second output, and a third quantum wire extending between the first and second outputs, the three quantum wires together defining a ring. A controllable-length quantum wire electron stub tuner is connected to the ring. As charge carriers propagate from the input around the ring the stub tuner is used to control the quantum interference of the charge carriers resulting in local maxima and minima at various points around the ring. Setting the stub to a first length results in a local maximum at the first output and a local minimum at the second output, and the charge carriers can propagate to the first output and not the second output.

Abstract: A high frequency switching circuitry comprising the following elements. At least one input signal terminal is provided into which an input signal is inputted. An output signal terminal is also provided, from which an output signal is outputted. A first resistive switching circuit is connected between the input signal terminal and a first node. The first resistive switching circuit has first and second signal transmission channels having first and second resistances. The second resistance of the second channel is much higher than the first resistance of the first channel. The first resistive switching circuit switches the first and second signal transmission channels. A first switching element is connected between the first node and the output terminal. A second switching element is connected in series between the first node and a ground line.

Abstract: It is an object of the present invention to provide a variable attenuator which can be produced at a low cost and can suppress production of unnecessary resonance and propagation. When the radio frequency resistance values of PIN diodes 13 and 14 are higher than a characteristic resistance value of a signal line interconnecting radio frequency signal input terminal 1 and radio frequency signal output terminal 2, the sum of voltages applied to PIN diode 11 and PIN diode 13 and the sum of voltages applied to PIN diode 12 and PIN diode 14, that is, V3, are controlled so as to be fixed.

Abstract: A multiple terminal selector switch for use with millimeter-wave signals has a layout of components enabling the switch to be constructed on a monolithic microwave integrated circuit (MMIC) chip while maintaining adequately low cross talk among ports of the switch to retain isolation among its ports. The circuitry includes a transmission line having multiple taps spaced apart by an integral number of half wavelengths of the signal, wherein the taps connect to separate ports via arms of the circuit. Each arm has an electronically switchable element for producing open or short circuits for connection and disconnection of a switch port from the transmission line. One primary tap of the transmission line is unswitched and connects with a further port from which, or to which, signals of the other ports are selectively switched.

Abstract: An antenna switching circuit (55) is constructed by a circulator element (63) having three terminals, of which the first terminal (CTX) is connected to the transmitting circuit, the second terminal (CANT) is connected to a first antenna (4), and the third terminal (CRX) can be connected to the terminal resistance (64) through a first switch element (62); a second switch element (60) capable of connecting the third terminal of the circulator element to the receiving circuit; and a third switch element (61) capable of connecting a second antenna (22) to the receiving circuit, whereby, it is no longer necessary to use a duplexer circuit having large insertion loss, the whole construction can be miniaturized, and the insertion loss can be reduced.

Abstract: In a switch semiconductor integrated circuit, a switch for high frequency signal is constituted by four field-effect transistor stages connected in series to the first to fourth signal paths arranged in a ring shape and two field-effect transistor stages connected which are in a shunt position with respect to the signal paths such that two signal paths are positioned between two field-effect stages which are opposite to each other. At this time, the same voltage is impressed to the signal paths which are in a position opposite to each other among four signal paths, and the control voltage which are complementary to each other is impressed to the adjacent signal paths.

Abstract: A low loss electronic radio frequency (RF) switch (100) for switching RF energy between an antenna port (115), a receiver port (113) and a transmit port (101) used in a two-way radio transceiver. The RF switch includes a first diode (105) connected between the transmit port (101) and the antenna port (115). A first capacitor (103) is connected between the transmit port (101) and a ground potential while an inductor (107) and second capacitor (111) are serially connected between the antenna port (115) and a receive port (113). A second diode (109) is connected between the inductor (107) and the second capacitor (111) and the ground potential. The antenna port (115) is normally connected with the receive port (113) when idle. When direct current is applied to the transmit port (101) the first diode (105) and second diode (109) are biased into a low impedance state connecting the antenna port (115) to the transmit port (101) and isolating the receive port (113) from the antenna port (115).

Abstract: A changeover switch switches connection between an antenna and a transmitter amplifier and connection between the antenna and a receiver low noise amplifier, from one to the other. A first wire having characteristic impedance of 50 .OMEGA. connects the antenna and the changeover switch. A receiver matching circuit matches input impedance of the receiver low noise amplifier with the output impedance of the transmitter amplifier. An antenna side matching circuit matches the input impedance of the receiver low noise amplifier, which is matched with the output impedance of the transmitter amplifier by the receiver matching circuit, and the output impedance of the transmitter amplifier with the characteristic impedance of the first wire. The transmitter amplifier is connected with the changeover switch via a first coupling capacitance, and the receiver matching circuit is connected with the changeover switch via a second coupling capacitance.

Abstract: This invention is intended to realize a high frequency switch with a low distortion characteristic. In an SPDT switch consisting of a plurality of FETs, the FET on the receiver side through which a received signal passes and the shunt FET on the transmitter side are each formed of series-connected FETs, and a capacitor is connected between the first gate and the source and between the second gate and the drain. An inductance is connected in parallel with a series connection of FETs. This easily realizes a high frequency switch having a low voltage and a low distortion characteristic. The 1 dB compression level, an index of input-output characteristic, can be improved more than 5 dB over the conventional SPDT switch at an input level.

Abstract: A switching circuit is made by serially connecting two field effect transistors in series in a small-signal transmission path, each of the transistors being applied with a substantially equal voltage, so as to lower a voltage applied to each of the FETs in the OFF state by voltage division, with the result that a high withstand voltage of the transmission path can be attained and a linear output can be obtained even when a large electric power is transmitted.

Abstract: A latching electromagnetic RF switch is provided with an armature having a permanent magnet mounted thereon. An electromagnetic coil surrounding the armature has a ferromagnetic member mounted opposite the armature. A spring holds the permanent magnet away from the ferromagnetic member, latching the switch in a first position. In a second position, the permanent magnet attracts the ferromagnetic member and holds the armature against the force of the spring latching the switch.

Abstract: A high-frequency switch includes first to third high-frequency switch circuits. The first high-frequency switch circuit has a first transmission line connected between a first antenna port and a first receiving circuit port, and a first diode connected between said first receiving circuit port and ground. The second high-frequency switch circuit has a third transmission line connected between a second antenna port and a second receiving circuit port, and a second diode connected between said second receiving circuit port and ground. The third high-frequency switch circuit has a third diode connected between the first antenna port and a transmitting circuit port, and a fourth diode connected between the second antenna port and the transmitting circuit port. With this configuration, ports are connected or disconnected, or connections are switched, by setting the first to fourth diodes to the on state or the off state.

Abstract: A transmit-receive switch which can be integrated. The receive diplexer of the switch comprises a parallel resonant circuit which can be completed or connected into the switch via a heterobipolar transistor. The transmit diplexer includes a series resonant circuit or a parallel resonant circuit which is connected into the switch circuit via a further heterobipolar transistor. Each of the heterobipolar transistors is rendered conductive or non-conductive via the applied HF power. That is, a high HF power, as is present in the transmission case, causes the respective transistor to become conductive and via the respective resonant circuits, cause the receive diplexer to become high impedance and block any signal, and cause the transmit diplexer to become low impedance and pass the high HF power substantially undampened.

Abstract: Highly reliable, light-weight, and low power-consuming microwave redundancy and re-routing electronic switches suitable for on-board satellite applications permit rearranging of communication paths for up- and down-link communications and re-routing of microwave signals to redundant devices in the event of on-board hardware failures.

Abstract: A mobile terminal device for telecommunications includes a switch circuit which comprises two field effect transistors connected in series to an input terminal, an output terminal and a common input/output terminal respectively, for AC signals. The switch circuit includes control devices which are cyclically shifted for the two transistors. The control devices are formed by pulsed multiplexed bias voltages of amplifiers which produce and receive the AC signals, and by a logic OR-circuit of diodes and resistor. The voltages on the terminals of the diodes are connected between the gate and source of the transistors for their cyclically time-shifted control.

Abstract: A radio frequency (RF) switch accessory (100) for use with a two-way radio (101) includes an input port (203), antenna port (215) for connection to an antenna and a remote port (213). The RF switch accessory (205) is used to control an electro-mechanical relay (207) for electrically connecting the input port (203) either between the antenna port (215) for connection to the radio antenna or the remote port (213). The invention allows for RF energy produced by the radio (101) to be easily switched to the remote port (213) without disconnecting an antenna from the radio.