Abstract: A microwave semiconductor switch wherein first and second field effect transistors and first, second and third input/output microstrip lines are integrally formed on a semiconductor substrate. The first field effect transistor is connected in series between the second input/output line and a junction point of the first, second and third input/output lines at a position adjacent to the junction point. The second field effect transistor is connected at a second position spaced approximately a quarter of the wavelength from the junction point between the second position and the ground. The drain electrodes and source electrodes of the first and second transistors are placed at the same potential. The transmission paths for microwaves are switched by varying a bias voltage applied to the gate electrodes of the field effect transistors.

Abstract: A patch antenna, which may be one element of an antenna array, is formed on one broad surface of a semiconductor plate. A ground plane is formed on the second broad surface. This semiconductor is doped in regions near a periphery of the patch to define a semiconductor PN junction have electrode contacts to the patch and to the ground plane. The junction has capacitance which tunes the patch antenna. The characteristics of the junction are controlled by bias to selectively tune the patch antenna. The bias is a direct voltage in one embodiment of the invention. In another embodiment, the junction work function itself provides a bias which is controlled by temperature control of the diode.

Abstract: An N.times.M signal routing matrix has low loss. The N input ports are connected to N input transmission lines, and the M output ports are connected to M output transmission lines. A plurality of interconnects interconnect the input and output transmission lines at their crossing points. The points of connection of the interconnects to any one of the input or output transmission lines are spaced .lambda./2 (or multiples thereof) apart along the transmission line. Each interconnect includes a transmission line at least .lambda./2 long, and each includes a short-circuiting switch arrangement capable of short-circuiting the inteconnecting transmission line at point(s) .lambda./4 (or odd multiples thereof) from the ends of the interconnecting transmission line.

Abstract: A microwave planar switch matrix for selectively connecting various ones of M inputs to N outputs. The switch matrix includes a semi-insulative substrate on one side of which are conductors arranged in rows and columns, the interconnection of the rows and columns forming the intersections of the matrix, a plurality M.multidot.N of two-way active power dividers arranged in the rows near each intersection, respectively, and a plurality M.multidot.N of two-way power combiners arranged in the columns near the intersections, respectively, and M.multidot.N switches selectively connecting respectively one output of the power dividers to one input of the power combiners. Because the power dividers and power combiners utilize active components, net power gain through the matrix is possible. Air bridges separate the row and column conductors at the intersections.

Abstract: A broadband switching circuit has two or more field controlled switch elements coupled in series between an input terminal and an output terminal. A passive, lossy network is coupled between a junction of consecutive switch elements and a virtual around. The off state isolation of the switch elements is improved and signal losses are reduced significantly. When utilized in multichannel switching circuits, only a single switching voltage polarity per channel is required.

Abstract: An R.F. switch includes a directional coupler with a main line and a quarter wavelength coupled arm. One end of the main line is connected to a first input port and the other end is connected to a first output port. The coupled arm is selectibly terminated at one end in either its characteristic impedance or a short. A PIN diode controls the termination. The second end of the coupled arm is connected to a second input port. A PIN diode switch is connected between the second end of the coupled arm and a second output port. In a first position, signals present at the input ports are combined and appear at the first output port. The directional coupler provides isolation such that the signal at the second input port is not coupled to the first input port. In the second position, the signal at the second input port is disconnected from the first output port and only connected to the second output port.

Abstract: A hybrid power combiner and controller device is disclosed. The device includes a multiple branch hybrid network, with PIN diodes employed to selectively short circuit the midpoints of the branch lines to ground. With the PIN diodes biased to the open circuit condition, the device behaves as a conventional hybrid combiner, for example, to combine the power produced by two input sources at the device output port. With the PIN diodes biased to the conductive condition, thereby shorting the branch line midpoints to ground, the device behaves as a matched multiple stub filter tuned to the desired band. Substantially all the power provided by one input power source will be provided at the device output in this case.

Abstract: In a magnetic resonance imager or other spectrometer, an interface (D) selectively connects quadrature probe coils (E) with a transmitter (C) and with a receiver (F). The interface includes a first RF switch (10), such as a first PIN diode (12) which has a low radio frequency impedance state for passing transmitted radio frequency signals to the probe coils and a high radio frequency impedance state for blocking the passage of radio frequency signals to the probe coils. A quarter wave length cable (20) or the equivalent is connected between the probe coils to shift the phase of the radio frequency signals 90 degrees. A second radio frequency switch (40) includes a second quarter wave length cable (42) and a second pin diode (44) which selectively pass and block radio frequency signals from passing between the probe coils and the receiver.

Abstract: A continuously variable phase shifter for the phase range from 0.degree. to 90.degree., switchable phase shifters switchable between 0.degree. and 90.degree. and a continuously variable phase shifter for the phase shift range of 0.degree. to 360.degree. are disclosed. Each of the phase shifters relies on dual gate FET devices to provide the required phase shift in a compact structure while providing sufficient gain to avoid signal losses through the phase shifter. The transmission phase shift through a dual gate FET device is controlled by the DC bias on its second gate and by the type of reactive termination on that gate. A capacitive termination provides a transmission phase shift which is substantially independent of bias while an inductive termination provides a transmission phase shift which varies substantially linearly with bias voltage over a substantial range of bias voltage.

Abstract: A solid state radio frequency switching circuit is provided that exhibits up to 25 db isolation between output ports. The circuit integrates the switching versatility of a pin diode switch with the excellent signal isolation of a quarter wavelength combiner.

Abstract: A switched-line type phase shifter employs a reference, uniform transmission line and a coupled exponential transmission line. The coupled exponential line network provides a different phase shift but provides a phase shift versus frequency characteristic that over a wide frequency band matches the reference line.

Abstract: A switch circuit and assembly for selectively connecting any one of a series of inputs each carrying a number of VHF signals to any one of a series of outputs. Each input is applied to a respective input board and each output to a respective output board, the input boards being arranged in parallel and generally perpendicular to the output boards. Connections are made between any one input board and each output board by respective pairs of interengaging terminals arranged adjacent the board edges. Isolating plates are interleaved with the boards, the plates located between the input boards extending into the spaces between the output boards, and the plates located between the output boards extending into the spaces between the input board, thereby defining a series of four sided isolating structures around each interengaging pair of terminals.

Abstract: The method of distributing a signal from an input conductor to a plurality of relay terminals at known locations in the plane of a circuit board which comprises meandering said input conductor to intersect said terminals in succession while avoiding other relay contacts. The meandering conductor path gives this type of relay switching system the ability to maintain a switching system characteristic impedance, Z.sub.0, in a simple, cost effective manner.

Abstract: This invention allows the combination of any M of N signal inputs, combines the signals inputs in phase, and does not require switches to terminate unused inputs.Microstrip switching means provide an array of N quarter-wave tuners and an associated single, common, quarter-wave tuner that are interconnected by N semiconductor switching means. Each of the N semiconductor switches is connected with one of the N quarter-wave tuners and is operable to provide a low impedance between its connected quarter-wave tuner and the single common quarter-wave tuner.Microstrip connecting means for the microstrip switching means forms an array of N transmission lines N associated quarter-wave transformers for semiconductor switch biasing and a single transmission line.

Abstract: A transmission line device for coupling two radio waves, such as horizontal and vertical polarized waves such as satellite transmissions, which are traveling in a particular direction along a pair of main transmission lines, selectively to a branch line without problem of mismatch, wherein the branch line is composed of a single feeder and selection of the two waves is effected simply by applying a positive or negative voltage to the feeder.

Abstract: A dynamic electronic switch (10) having n inputs (2) and m outputs (4), where n and m are any positive integers. The electromagnetic signal on any given input (2) may be switched onto any number of outputs (4), but any given output (4) may have no more than one input signal switched thereonto at any given time. Switching nodes (8), comprising at least one switching diode (11, 13, 15) and a directional edge coupler (17) embedded between two parallel ground planes (9, 1) in a planar mother board (5), perform switching at each intersection of an input (2) and an output (4). Each output (4) is mounted on a planar dielectric summer board (6) positioned orthogonal to the mother board (5).

Abstract: A dual-gate MESFET forms the basic building block for a variety of signal coupling applications for use in adaptive microwave communication systems. By controlled biasing of its electrodes, a dual-gate MESFET may be operated as an active signal combiner/divider device. As such, it is capable of providing controlled signal transfer functions, so that it may be used in a variety of adaptive system applications including controlled switching devices, channelized power dividers, active channel fitters, phase shifters, complex weighting devices, etc.

Abstract: A bidirectional switch for selectively switching a microwave frequency signal between one of two signal paths. The switch includes a pair of field effect transistors, and a pair of transmission lines coupled together at one end thereof to provide a common port. Each second end of each microwave transmission line is coupled to a drain electrode of one of such field effect transistors to provide a branch port at each second end of each microwave transmission line. The electrical lengths of each transmission line are selected in accordance with the operating wavelength of the circuit to provide an impedance corresponding to an open circuit at one end, when a short circuit is provided at the opposite end. A signal is coupled between the common port and a selected one of the branch ports, in response to a pair of complementary binary control signals fed to the gate electrodes of the FETs.

Abstract: An improved microwave multi-throw switch incorporating PIN diodes wherein the PIN diodes are mounted orthogonally to the conductive stripline.

Abstract: A variable microwave stripline power divider, in which the power seen at h of two outputs can be varied over a wide range without appreciably changing the power seen at the other output. In one embodiment, this is accomplished mechanically by shorting posts connecting the patch member to a ground plane member of the device at selected points. In another embodiment of the invention, this is accomplished electronically by a plurality of electronic switching devices connected between a like plurality of patch member shorting points and a ground plane member, which are selectively activated by a microcomputer.

Abstract: A one port-to-M port passive signal power divider circuit (or combiner circuit) where M>2 and .noteq. 2.sup.N, M and N are integers, includes M - 1 two-way in-phase passive power dividers having a signal delay D through each path in one or more delay devices having delay D. Each output of each two-way power divider is coupled to an input of another power divider, a delay line or an output port, the arrangement being such that the delay through all ports of the power divider are equal. In accordance with a further embodiment of the invention the outputs of a passive power divider are connected to two-way switches using active components. The switches under control of a control circuit are utilized to switch the input signal to the power divider to any one of 2.multidot.M output terminals of the switches.

Abstract: In a switching network in matrix form for megahertz frequency signals, including: a multilayer printed circuit board having a plurality of row signal lines located in a first plane, a plurality of column signal lines located in a second plane and extending transverse to the row lines, the row and column signal lines intersecting one another in an intersection area, control and/or shielding conductors surrounding the lines, and metal shields enclosing the planes; a crosspoint array integrated on a chip and providing a plurality of crosspoints for the intersection area, each crosspoint presenting two semiconductor switches arranged to couple a respective column signal line to a respective row signal line; and a shielded package enclosing the chip, each line is constituted by a balanced pair of stripline conductors and is terminated at each end by its characteristic impedance.

Abstract: The planar transmission line attenuator and switch is formed on a flat piece of semiconductor material. Transmission line metallic conductors are deposited on a flat surface of the semiconductor material, and at least one of the metallic conductors forms a Schottky barrier contact to this flat semiconductor surface. The gap between the metallic conductors defines a shunt current path through the semiconductor material. The semiconductor material at the surface in contact with the transmission line conductor must be conductive. By applying a bias voltage to the metallic conductor forming the Schottky barrier contact, the conductivity of the shunt path can be controlled by changing the depletion layer width across the Schottky barrier. A plurality of planar transmission line switches can be combined into multi-port networks, examples of which are cross-bar switching devices and .beta. element switching devices.

Abstract: A redundant microwave switching matrix providing equal power distribution of any of a plurality of microwave input signals among one or more of a plurality of microwave output signals. The redundant switching matrix used in a communication satellite selectively couples one or more of a plurality of input microwave signals received by receiving antennas among one or more of a plurality of output microwave signals radiated by transmitting antennas. The means for coupling the input and output microwave signals is provided by a pair of directional couplers diametrically positioned at each coordinate of the switching matrix. A controller selectively enables a pair of PIN diodes, internally positioned within each directional coupler, to perform the desired coupling. Diametrically positioned directional couplers, having a pair of PIN diodes, provide a highly reliable and flexibility microwave switching matrix.

Abstract: A microwave switching power divider for selectively dividing and switching microwave energy among a plurality of outputs to other microwave devices includes a pair of parallel, spaced-apart circular ground planes defining a microwave cavity with multi-port microwave power distributing switching circuitry formed on opposite sides of a thin circular dielectric substrate disposed beween the ground planes. The power distributing circuitry includes a conductive disk located at the center of the substrate and connected to a source of microwave energy. A plurality of tapered radial power dividing transmission lines for intercepting the standing waves are symmetrically disposed about and connected to the conductive disk. Within each line, a high speed, low insertion loss switching diode and a DC blocking capacitor are connected in series between the outer end of a transmission line and an output port.

Abstract: A microwave diode having an integrally formed fixed resistance layer to provide a monolithic structure. The resistance layer has an approximate value of 50-ohms when the diode is in the forward biased state. The diode in monolithic form is adaptable to be soldered directly to a housing electrically connected to the ground plane of the microstrip circuit. In the reverse bias state the junction capacitance of the structure is small enough, typically 0.02 to 0.05 pf, to isolate the diode from the microstrip circuit thereby minimizing the insertion loss of the device. Packaged varieties of the monolithic structure are applicable to stripline, coaxial and waveguide microwave circuits.

Abstract: A quadriphase modulator, designed in a planar metal geometry for operation in the microwave frequency range, uses Schottky barrier diodes as the switching elements, and is capable of operating at bit data rates up to 15% of the carrier frequency. The microwave circuit employs a microstrip power splitter that couples the carrier signal to two biphase modulators while providing DC isolation. Each biphase modulator includes coplanar-to-slot transmission line transition, with a pair of diodes controlling the phase shift across the transition. The diodes are connected in reverse polarity and the bias for switching the diodes is controlled by the modulating signal. The slot lines from the two biphase modulators are coupled through a microstrip transition and through a Lange 90 degree hybrid to the output load.

Abstract: A planar microwave switch matrix is composed of three-state phase shifter switches, a planar crossover and switchable 3-dB attenuators. The three-state phase shifter switches are each composed of two planar 3-dB quadrature hybrid couplers interconnected by two switchable phase shifters. The phase shifters are both switchable between zero phase delay and a predetermined phase delay, but the predetermined phase delay is different for each phase shifter. The planar crossover is composed of two cascaded 3-dB quadrature hybrid couplers. The construction of all components of the switch matrix is readily implemented using microwave integrated circuit (MIC) technology. The switch matrix is intended for use in switched satellite time division multiple access (SS-TDMA) systems but can be remotely configured for broadcast applications.

Abstract: A circuit for controlling the switching of a high-power diode microwave switch with a relatively low-power diode switching circuit by utilizing a high-power quadrature hybrid coupler in the switch with the switch input and diode switching element being connected to one leg of the coupler, the output of the switch being connected to a second leg of the coupler, the third and fourth legs of the coupler being capacitively grounded to provide an a-c short at RF frequencies and thereby reflect microwave energy back into the switch, and a switch control circuit being connected to the third leg of the coupler. The coupler divides the power input to the switch so only a portion thereof is incident on the diode switch control circuit, and thus provides isolation between the control circuit and the switch input and output.

Abstract: An n.times.m wideband RF switching matrix constructed from modules which are interconnected by simple series paths. As many modules as required can be juxtaposed to form switching matrices of any order. Each module includes n inputs and a different lumped element directional coupler connected to each input, each directional coupler having a coupled output. Each module further includes a conductor coupled to a matrix output. The coupled outputs of the directional couplers on a given module are connected through single-pole, single-throw switches to the conductor. The direct outputs of the directional couplers are coupled to the inputs of the n directional couplers on the next module in the series.

Abstract: A diode microwave switch is disclosed having both low power dissipation loss and a low voltage standing wave ratio by the techniques of mounting microwave diodes on pedestals and interconnecting them with air line microstrip connections and utilizing special impedance matching techniques. Voltage standing wave ratios of 1.15:1.00 with 0.3 db loss in a three diode 60 db isolation switch are readily obtained.