Abstract: The present invention is intended to prevent an unnecessary standing wave from being generated by simplifying a circuit in a transmission line switch to be used in a block-down converter for receiving, for example, satellite broadcasting. First and second amplifiers are adapted to be selectively switchable to an ON state to/from an OFF state and are arranged in first and second input lines and are respectively provided with a connection line for connecting the first and second input lines and a common output line. The connection line comprises a first transmission line 3 connected to an end part of the first input line, a second transmission line connected to an end part of the second input line and a third transmission line connected to an end part of the common output line. The first to third transmission lines are arranged in parallel to one another to transmit signals and form a DC block circuit adapted to selectively shut down a DC bias to the amplifiers.

Abstract: A high-frequency switch having first, second, third and fourth ports, and capable of connecting either of the first and second ports to either of the third and fourth ports. The switch has first, second, third and fourth diodes connected between the first and third ports, the first and fourth ports, the second and third ports, and the second and fourth ports, respectively. A first distributed parameter line and first capacitor, connected together in series, are connected from one end of each diode to a reference potential (ground). A resistor has one end connected to a connection point between each first distributed parameter line and the corresponding first capacitor, and a control voltage terminal connected to the other end of the resistor. A second distributed parameter line is connected from each of the first and second ports to the reference potential.

Abstract: In an antenna duplexer, one antenna is used by switching transmission signals and reception signals having different frequencies. The antenna duplexer includes a high-frequency switching circuit and a band-pass filter. The high-frequency switching circuit supplies the transmission signals from a transmission part to the antenna. The band-pass filter outputs the reception signals outputted from the antenna to the predetermined receiving circuit. In the band-pass filter, the frequency characteristic is selected and set to impress the frequency of the transmission signals, and simultaneously the reflected wave generated at the input end so that impedance increases at the frequency band of the transmission signals.

Abstract: An antenna switching device of the present invention includes: a transmitting terminal for receiving a transmitting signal; a first antenna terminal connected to a first antenna; a second antenna terminal connected to a second antenna; a receiving terminal for outputting receiving signals received at the first antenna terminal and the second antenna terminal; a selecting unit for selecting one mode among a first mode for outputting a signal corresponding to the transmitting signal to the first antenna terminal, a second mode for outputting the receiving signal received at the first antenna to the receiving terminal, and a third mode for outputting the receiving signal received at the second antenna to the receiving terminal.

Abstract: What is described is a commonly coupled high frequency transmitting/receiving switching module (100). The switching module (100), has a transmitting circuit (102), a receiving circuit (104), an antenna circuit (106), an external circuit (108), a coupling circuit (110) and control circuits (124, 126). The switching module may be switched between one of four circuit paths (202, 204, 206, 208) each path incorporating an integral harmonic filter (210, 212). This structure is adapted for use in a multi-layer ceramic integrated circuit, and provides the advantage of minimizing current consumption with a minimal number of components.

Abstract: A device for tuning a combiner filter. The measuring signals (P.sub.rl . . . P.sub.rn, P.sub.F1 . . . P.sub.Fn) of a number of different combiner filters are multiplexed to the same detectors. Multiplexing allows the measuring and adjusting electronics required by the tuning and adjusting means of combiner filters to be simplified considerably especially with a high number of combiner filters. Multiplexing of measuring signals is used primarily to select the sample signals of the forward and reflected power of one and the same combiner filter to be tuned for the measuring electronics. In the invention selectors for reflected power and forward power are independent of each other, which allows isolation measurement between different channels. The sample signal of the forward power of one combiner filter and the sample signal of the reflected power of another combiner filter are thus connected to the measuring electronics.

Abstract: A predistortion linearizer (10) and method for distorting an AC input signal (42) to a power amplifier (24) provide a distortion to the input signal which is complementary to a distortion, in terms of gain and phase, introduced by the power amplifier as a function of signal amplitude, thereby to linearize the power amplifier. The linearizer includes a switching circuit (26, Z.sub.1 28, Z.sub.2) having an input terminal (16) and an output terminal (20) and a pair of antiparallel diodes (26, 28) connected between the input terminal and the output terminal of the switching circuit. The linearizer has also an impedance circuit (Z.sub.3) comprising solely passive electrical elements connected between the input terminal and the output terminal of the switching circuit, wherein elements of the impedance circuit have values selected to introduce the complementary distortion to the input signal as a function of amplitude of the input signal to linearize the power amplifier.

Abstract: A switch for transmitting a signal with gain from one of a plurality of input transmission lines (10A,10B,10N) to a common output line (14) is described which achieves high isolation by omitting the transmission line between the output matching section and the junction of the input and the output. In one embodiment the output of each amplifier, a field effect transistor (38,40), is coupled directly to a common output (34) and the output matching circuitry is also omitted from the input lines, there being provided a common output matching and bias network located in the output line. In another embodiment the output matching network (26a,26b;64a,64b) is coupled directly to the common junction (16;56) and the transmission line length between the output matching network and the junction is omitted for each input line.

Abstract: The present invention relates to an arrangement for separating transmission and reception accomplished through one and same antenna (A) in a transceiver, said arrangement comprising a filter and a switching element (K) and being provided with a common port to be coupled to the antenna (A), a transmitter branch (TX) port (T) to be coupled to the transmitter of the transceiver and a receiver branch port (RX) port (R) to be coupled to the receiver of the transceiver, and in which, as a response to a control signal, the switching element couples operationally to the common port alternatively the transmitter branch port (T) and the receiver branch port (R). The arrangement comprises a filter (S.sub.T,S.sub.F,S.sub.1,S.sub.2) including transmission line resonators, said filter being provided with adaptation couplings to be coupled to the transmission line resonators and for accomplishing couplings between the transmission line resonators.

Abstract: A high-frequency switch, having a first port, a second port and a third port and serving to selectively connect the second port to the first or third port, includes a first distributed constant line and a second distributed constant line which are connected in series between the first and second ports, a third distributed constant line and a fourth distributed constant line which are connected in series between the second and third ports, a first diode connected between the first port and the ground, a second diode connected between a junction point between the first and second distributed constant lines and the ground, a third diode connected between a junction point between the third and fourth distributed constant lines and the ground, a fourth diode connected between the third port and the ground, a first resistor and a second resistor which are connected in series between grounded electrodes of the first and fourth diodes, and a third resistor and a fourth resistor which are connected in series between g

Abstract: A switch circuit for a cellular radiotelephone operable in a TDMA communication scheme. The switch circuit is disposed upon a plurality of tandemly-positioned ceramic substrates having transmission lines disposed upon one of the ceramic substrates. The switch circuit alternately connects transmitter circuitry to an antenna or receiver circuitry to the antenna, thereby alternately to permit transmission or reception of signals generated by, or received by the radiotelephone. Because circuits disposed upon ceramic materials are of low insertion losses, the switch circuit is advantageously utilized to form a portion of the radiotelephone.

Abstract: Broadband, monolithic, planar m.times.m and m.times.n transfer switches with diode switching elements are disclosed. Symmetry of the switches maintain equal insertion amplitude and phase performance. Compensation of phase unbalance caused by diode parasitic capacitance is provided by inductors serially coupled between the diodes and the input and output terminals of the transfer switch. Stripline transmission lines are utilized and isolation between the transmission lines is provide in regions of stripline cross over in the plane.

Abstract: A high-frequency switch 20 includes a first diode 24. An anode of the first diode 24 is connected to a transmitting circuit TX via a capacitor 22, and is grounded via a first strip line 26 and a capacitor 28. A first control terminal 30 is connected to a connecting point of the first strip line 26 and the capacitor 28, and a control circuit for switching the high-frequency switch is connected to the first control terminal 30. A cathode of the first diode 24 is connected to an antenna ANT via a capacitor 32. One end of a second strip line 40 is connected to the antenna ANT via the capacitor 32. The end of the second strip line 40 is grounded via a capacitor 42. The other end of the second strip line 40 is connected to a receiving circuit RX via a capacitor 44, and is grounded via a second diode 46 and a capacitor 48.

Abstract: The present invention discloses a reconfigurable microstrip transmission line network having a microstrip circuit consisting of an RF ground plan separated from a transmission layer by a dielectric layer. The transmission layer comprises a silicon material responsive to a plurality of excitation sources. The excitation sources generate excitation beams which upon interacting with the surface of the transmission layer actuate a conductive pathway. By alternately actuating and deactuating the excitation sources and varying the excitation beams, the configuration of the microstrip transmission line network upon the transmission layer may be reconfigured as desired.

Abstract: A port selection circuit in which a port selection section and a variable frequency filter are integrated on a substrate. The port selection circuit selectively connects any one of first to n-th ports to an (n+1)-th port and comprises first to n-th switches. Each of the switches includes one end connected to a corresponding one of the first to n-th ports and the other end connected to a common connecting point. When any one of the first to n-th ports is selected, a variable frequency filter connected between the common connecting point and the (n+1)-th port is set to a frequency characteristic for transmitting the frequency assigned to the selected port.

Abstract: A microwave switch circuit includes a first impedance conversion circuit, one end of which is connected to an input terminal; a resonance circuit connected between an output of the first impedance conversion circuit and ground and including a parallel connection of a field effect transistor and a resonance inductor; and a second impedance conversion circuit connected between the output of the first impedance conversion circuit and an output terminal. One microwave switch circuit may be connected between an antenna terminal and a signal input terminal and another microwave switch circuit may be connected between the antenna terminal and a signal receiving terminal. The microwave switch circuit output terminal and input terminal may have an impedance of 50 .OMEGA. and the output of the first impedance conversion circuit may have an impedance lower than 50 .OMEGA.. The microwave switch circuit may include one-fourth wavelength transmission lines as the first and second impedance conversion circuits.

Abstract: A high-frequency switch includes a multi-layer board or a laminate. The laminate is formed by laminating many dielectric layers 14. First and second strip lines, capacitors and so on are provided inside the laminate. Each of the capacitors is formed by the combination of the dielectric layer and two capacitor electrodes which sandwich the dielectric layer. Also, first and second diodes and so on are mounted on the laminate. Furthermore, external electrodes are formed on portions of four sides of the laminate.

Abstract: An integration of a micromachined actuator and a signal transmission structure includes a thermal actuator on a side of a displaceable signal line opposite to a fixed signal line. The actuator includes first and second legs. The first leg has a cross-sectional area greater than the second leg, providing a differential in electrical resistance. As current is channeled through the legs, the second leg will elongate more and will deflect both of the legs. The deflection is in a direction to press the displaceable signal line into signal communication with the fixed signal line. Optionally, a thermally operated reset actuator can be positioned to provide a mechanical return of the displaceable signal line. In a preferred embodiment, a microwave transmission environment is provided.

Abstract: A micromachined signal switch for vertical displacement includes a fixed substrate having at least one signal line and includes an actuator substrate that is thermally actuated to selectively connect a second signal line to the first signal line. The actuator substrate includes a plurality of legs constructed of materials having sufficiently different coefficients of thermal expansion to create stresses that arc the legs when the legs are subjected to elevated temperatures. In the preferred embodiment, a first material for forming the legs is silicon and a second material is a metal, such as electroplated nickel. A displaceable contact region may be formed integrally with the actuator substrate, but the contact region is preferably a region of an interposer substrate between the fixed substrate and the actuator substrate.

Abstract: A high frequency transceiver includes a transmit/receive switch which is coupled to a transmission path and to a receive path of the module. The transmit/receive switch includes a 3 dB directional coupler having first, second and third ports, and a decoupled port which is connected to the receive path. Two HF power amplifiers are connected to the first and second ports of the transmit/receive switch to form a balanced amplifier in the transmission path. An HF switch is connected to the first and second ports of the transmit receive switch for short-circuiting the HF output of the balanced amplifier. A switching device is connected to the HF switch and to the receive path for selectively switching the transmission path and the receive path to be operational.

Abstract: A microwave crosspoint blocking switch matrix and assembly employing multilayer stripline and pin diode switching elements is employed to selectively electrically couple and decouple input transmission lines to output transmission lines without severance of the transmission lines and insertion of a series switch. The microwave crosspoint blocking switch matrix assembly employs pin diode arrays coupled to input and output transmission lines at respective crosspoints. In order to route a signal from a specific input line to a selected output line, the pin diode array at the input/output transmission line crosspoint is activated and each transmission line is shorted at points one-quarter wavelength distant from the crosspoint to reflect, ideally, an infinite impedance at the interconnection point. Therefore, a desired signal cannot propagate in any direction except from the selected input line to the desired output line.

Abstract: An antenna switching apparatus for selectively connecting an antenna to either a transmitter for transmitting a transmitting signal having a transmitting frequency, or a receiver for receiving a receiving signal having a receiving frequency, which is different from the transmitting frequency, includes an antenna terminal electrically connected to the antenna; a transmitting terminal electrically connected to the transmitter, and a receiving terminal electrically connected to the receiver. A receiving filter for passing a receiving signal therethrough is electrically connected between the antenna terminal and the receiving terminal. An impedance adjusting element is electrically connected to an input end of the receiving filter, and has an element value such that an impedance when seen from the antenna terminal looking toward the receiving filter becomes substantially infinity at the transmitting frequency.

Abstract: A quantum wave guiding electronic switch includes a substrate which carries electron waveguides disposed in a fork-like configuration. Each of these electron waveguides is connected to a respective electron reservoir. Electrons are driven through the waveguides by voltage sources. Electrodes on the substrate generate an electric field which passes through the outgoing electron waveguides of the switch, and creates a potential difference therebetween. In one case, in which the electrons are transported ballistically, in the absence of electron scattering, this potential difference creates a phase mismatch between the outputs. An incident electron wave function having even parity is herewith switched to a quasi even electron wave function in the output that has the lowest energetic potential. When transportation is not ballistic and the electrons scattered to some extent, switching is effected by relaxation of incoming electrons to lower energy levels.

Abstract: A radio frequency circuit includes a first RF switch having a first common port coupled to an input port of the switch circuit and a first pair of branch ports and a second RF switch having a second common port coupled to an output port of the circuit and a second pair of branch ports. The radio frequency circuit further includes an RF propagation network having a first end coupled to a first one of said first pair of branch ports of said first RF switch and a second end coupled to a first one of said second pair of branch ports of said second RF switch. The radio frequency circuit further includes an RF termination having an impedance characteristic corresponding to an impedance characteristic of said first common port and having a first end coupled to a second one of said first pair of branch ports of said first RF switch and a second end coupled to a first reference potential.

Abstract: A high isolation broadband switching circuit includes a plurality of switching elements coupled in series alternatingly with transmission line segments. Each switching element has a low or very high impedance between first and second points responsive to first and second values of a control voltage, respectively. In a first embodiment, the switching element includes a PIN diode having a cathode coupled to a first transmission line and an anode coupled to a second transmission line. In a second embodiment, the switching element includes a field effect transistor (FET) having a drain coupled to a first transmission line and a source coupled to a second transmission line. A first resistor is coupled between the drain and the source for DC continuity between the drain and the source, and a second resistor coupled between a gate of the FET and ground for DC continuity. A bias voltage source is coupled through a resistor to one of a source and a drain of one of the FETs.

Abstract: A quadrant driver is disclosed, for use to drive the rotor of a microwave switch at 90.degree. from one given input-output configuration to another given input-output configuration and vice verse. The driver comprises a magnet and bearing holder rotatably mounted inside a housing. The holder supports, on one side, a thin, high magnetic density magnet and, on the other side, a bearing operatively connected to the rotor of the microwave switch to rotate this rotor when the holder is itself rotated, the holder and magnet being rotated between two rest positions, each of the rest positions corresponding to one of the two configurations of the microwave switch. A pair of coils are mounted concentric to mild steel cores mounted within the housing so that one of the cores faces with a given offset the magnet when the magnet is in one of its rest positions and the other core faces with a given offset the magnet when this magnet is in the other of its rest positions.

Abstract: This is a monolithic PIN diode switch circuit. The switch comprises: input ports, output ports, bias nodes and PIN diodes. Each port or node is connected to receive a bias signal. Preferably the PIN diodes are fabricated from GaAs or other III-V compound. This monolithic PIN diode switch offers broader band performance and smaller size. Other methods and devices are disclosed.

Abstract: The circuit is capable of selectively adding r.f. inputs at A, B dependent on the bias voltage applied to varactor diodes D1, D2. In one bias condition of the diodes and hence one value of capacitance, the reactance between A and B and between the output and point D is equal to the reactance of transmission lines 10, 11 formed by co-axial cables, and quadrature inputs at A and B are combined at output O/p. At another value of acpacitance of the varactor diodes, corresponding to another bias voltage, the capacitance of the diodes and the series capacitances C1, C2 resonate with the inductances L1, L2 and input A is effectively isolated from input B. The circuit can be used to produce a power amplified composite video r.f. signal, input A being connected to a power amplifier for the video signal only and input B being connected to a pulse amplifier for the sync pulses only. This permits more efficient use of the amplifiers compared to a single amplifier for amplifying the composite video signal.

Abstract: This is a monolithic PIN diode switch circuit. The switch comprises: input ports, output ports, bias nodes and PIN diodes. Each port or node is connected to receive a bias signal. Preferably the PIN diodes are fabricated from GaAs or other III-V compounds. This monolithic PIN diode switch offers broader band performance and smaller size. Other methods and devices are disclosed.

Abstract: A switching circuit comprises a transmission line having a specific impedance value and connected to an input terminal, a first switching portion including a plurality of first transistors connected in parallel between the transmission line and the ground, and a second switching portion including a second transistor and a resistor connected in parallel between the transmission line and an output terminal. The first transistors of the first switching portion and the second transistor of the second switching portion are complementally switched. Consequently, the switching circuit can be enabled to impedance-match with an objective circuit (for example, a measurement apparatus, a transceiver, a phased array system, and the like), and loss of signal transfer can be decreased regardless of the switching ON or OFF states of the switching circuit.

Abstract: A monolithic microwave switch matrix includes fully monolithic construction for crossovers as well as switches and input transmission lines configured as lumped equivalent transmission lines for reduced power loss. The crossovers include a grounded conductor located between the crossing transmission lines.

Abstract: A millimeter wave microstrip shunt-mounted PIN diode switch having its DC ground separate from RF ground is created by utilizing a fan structure (radial stub) having a radius of approximately one-quarter wavelength to provide an RF ground at that location and then coupling the DC bias supplies to that RF ground location. By doing so and by proper attention to known design practices for laying out microstrip circuitry, the need for blocking capacitors required by prior art arrangements is eliminated.

Abstract: A hybrid transfer switch comprises at least a pair of GaAs MMIC FET SPDT switches coupled together by a transmission line. PIN diodes are coupled to the transmission line and to DC bias circuitry. The hybrid switch performance closely approximates that of a mechanical/electromechanical transfer switch while providing improved repeatability.

Abstract: A method and apparatus for optimizing the signal transmission speed between a signal source and a signal receiver of a microelectronic circuit is disclosed. The method includes the step of providing a signal transmission path whose length provides a predetermined ratio between its resistance and characteristic impedance which will reproduce the transmitted signal at the receiving end upon the first signal transition. The length of this transmission path may be increased by using a nonhomogeneous line structure in which the characteristic impedance increases in the direction of the signal transmission. In one form of the invention, the signal transmission path is formed by interconnecting a plurality of micro-strip conductors disposed on different planes of a universally programmable silicon circuit board. Under the appropriate circumstances, a signal can travel through such a "semi-lossy" transmission path at approximately the speed of light.

Abstract: A semiconductor integrated circuit includes a first FET for controlling transfer of a high frequency signal, first and second capacitors connected to a gate of the first FET directly or through a resistor or a 1/4 wavelength line, a second FET having its drain connected to the first capacitor and its source grounded at high frequencies band, and a third FET having its drain connected to said second capacitor and its source grounded at high frequencies.

Abstract: A single fault/tolerant monolithic microwave integrated circuit field effect transistor switching arrangement. This circuitry provides for the high speed (up to 18 GHz) switching of RF input signals while maintaining a circuit which is single fault/tolerant. That is, a single FET within the circuit may become faulty and the operation of the switching arrangement remains unaltered. The circuitry also provides for a self-terminating feature inherent in this FET switch.

Abstract: A microwave element includes an impedance control circuit for controlling the capacitance between the source and the drain of an FET in the off state including a series-connected diode and capacitor connected in parallel between the source and drain of the FET and a circuit for applying a variable bias voltage to the diode. A microwave switch including two FETs includes two impedance control circuits for controlling the capacitances of the FETs. A microwave switched line phase shifter includes two transmission lines of different electrical lengths and four FETs, two of the FETs being connected in series at each of the ends of the two transmission lines. Impedance control circuits for controlling the capacitances of each of the FETs are included.

Abstract: A combined switch and filter comprising coupled first and second quarter-wave transmission line sections and switching elements for providing selective coupling and filtering between ports of the switch coupled to the ends of the quarter-wave sections.

Abstract: A digitally controlled active phase shifter with vernier control consists of a 180 degree phase bit in series with a 90 degree bit and a digitally controlled active vector generator with vernier control. The digitally controlled active vector generator consists of an active power divider with digitally adjustable amplitude, a pair of phase delay networks with an active power combiner employing vernier control. The power divider consists of two sets of parallel pairs of FET's in cascode configuration with all input nodes connected together and all output nodes from the same set tied together. The FET at the output node of each pair is a common gate configuration with its gate RF grounded through a bypass capacitor. The gate bias voltage is applied to the common gate FET to switch it ON or OFF to thereby provide a set of desired signal amplitudes which can be obtained by selecting the gain of each of the cascode stages in each of the parallel pairs.

Abstract: An electronic switch uses GaAs transistors to switch signals that have peak-to-peak voltage swings that exceed the breakdown voltage of the transistors. A two port impedance transformer (Z1) has a high input impedance and a low output impedance to transform a high voltage input signal (at T1) to a corresponding output signal having lower voltage, but higher current. This transformed signal is coupled to the second port of a three port impedance transformer (Z2) through a first GaAs transistor switch (Q1). A half wave rectifier circuit (D1, R7, R8 and C3) generates a negative DC voltage from the input signal (at T1), thereby eliminating the requirement for a separate bias voltage supply. A bipolar transistor switch selectively couples this negative bias voltage to the gate of the first GaAs transistor (Q1). The second port of the three port impedance transformer (Z2) has a lower impedance than either the first or third ports.

Abstract: A very low loss microwave modulator having two phase states: O, .pi.; the modulator comprising the following between an input (E) which receives a pure carrier at a frequency f.sub.O, and an output which delivers a carrier modulated with two phases states: a first switching element (17); in parallel therewith, a second switching element (18) connected in series with a main transmission line (19); and a control system (20) for causing a selected one of the first and second switching elements (17, 18) to be conductive and for causing the other one to be non-conductive. The invention is particularly suitable for microwave transmission.

Abstract: A transmission line switch allows a single output line (3) to be switched to one of two or more input lines (1,2) to which it is permanently connected at a common junction (4). Each input line (1,2) has an associated amplifier stage (10) which can be biased in a normal high gain (`on`) state, or in an isolation (`off`) state. Suitable biasing in the `off` state ensures that the amplifier stage output presents a low impedance to its own input line, the length (L) of which is chosen to reflect a high impedance at the junction (4) with the other lines. Correct design enables the return loss and insertion loss of the `on` path to be kept to low values while simultaneously offering a high insertion loss to the `off` path signals.

Abstract: A three-state, two-output R.F. power divider is configured as a microstrip device having an input port and first and second output ports. Between these three ports there is disposed a substantially T-shaped microstrip transmission line structure such that the input port is coupled to a base portion of the T-shaped structure and the first and second output ports are coupled to opposite ends of a top portion of the T-shaped structure. A substantially U-shaped microstrip transmission line structure is intercoupled with the T-shaped structure such that end portions of the U-shaped structure are coupled to the top portion of the T-shaped structure and a bottom portion of the U-shaped structure is coupled to the base portion of the T-shaped structure. A first PIN diode is coupled between a first location of the T-shaped structure and a ground plane brassboard underlying the dielectric layer on which the microstrip metalization is formed.

Abstract: A monolithic microwave integrated circuit switch includes a series field effect transistor having a source drain path in series with an inductive transmission line including plural taps. Source drain paths of plural shunt field effect transistors are connected to the taps. The source drain paths of the series and shunt transistors are biased so that the series and shunt source drain paths have complementary low and high impedance states. The high impedance state is capacitive, having a value on the order of magnitude of the inductive transmission line. During a first time interval, the capacitive and inductive impedances form a matched low pass filter to supply current from a microwave source to a load. During a second time interval, current from the microwave source flows through the shunt field effect transistors to be decoupled from the load.

Abstract: A non-radiating broadband microwave coupling device has a housing with first and second signal inputs and outputs, which are connected by respective first and second conductive connection line portions. A third output, also within the housing, is connected to these connection line portions by first and second semiconductor switches, which preferably are connected to parallel coupling line portions to provide inductive coupling. The semiconductor switches are selectively operable to close or switch the respective connection line through to the third output and open the other switch so that there is no significant power transfer to the third output. The connection line portions and the semiconductor switches are shielded within the housing. A corresponding terminator device has a termination resistor, which provides a ground connection for the coupling line portion not connected through to the output.

Abstract: A high frequency switch includes at least two transistors connected in series. By connecting the transistors in series the power handling capability can be increased by a factor of N.sup.2, where N is the number of transistors connected in series. The series is isolated by high impedance resistors and the transistors may be gallium arsenide field-effect transistors.

Abstract: A PIN diode switch suitable for switching radio-frequency voltages has a series circuit of two oppositely polarized PIN diodes, with a control current supplied to the junction between the two PIN diodes through the collector-emitter path of a transistor and through an inductor. The necessity of using a high-voltage power pack to generate a high reverse bias in order to avoid limiting the amplitude of the radio frequency voltage to be switched is not necessary, as in conventional PIN diode switches.

Abstract: Inductorless bias networks include a bias circuit having a bias return path which is coupled to and biases a variable impedance device in a relatively nonconductive state. Another bias circuit including a FET renders the variable impedance device relatively conductive in response to control signals so that one port is coupled to another port, for instance.

Abstract: A dual gate field effect transistor having an intermediate ohmic island between the two transistor halves is connected to operate as an amplifier-mixer for rejecting a frequency band. A paragraph continued series resonant circuit comprising an inductance and a capacitor is connected at one of its ends to the ohmic island of the field effect transistor and at the other end to ground. Polarization voltages are applied to each electrode of the dual-gate transistor so that the first half or part of the transistor extending from the source electrode to the ohmic island is brought into a state of saturation and the second part of the transistor extending from the ohmic island to the drain electrode is brought into a state of non-saturation.

Abstract: A circuit accepts as input a multi-frequency composite signal, such as that produced by a comb generator and passes on as an output signal switchably selected set of components of the input, so that the output signal may be varied by the selections of the components to be passed through. The circuit contains multiple filters in parallel with switches at the input and output of each.