Abstract: A reflection phase shifter connectable to a waveguide for shifting the phase of a high frequency signal received from the waveguide. The phase shifter includes a waveguide section having two pairs of opposite side walls and an end wall forming a short-circuit. The side walls define a cavity and an opening opposite to the end wall for communication with the waveguide. The waveguide section has a broad dimension between one pair of opposite side walls corresponding to the width dimension of the waveguide and a narrow dimension between the other pair of opposite side walls which is smaller than the height dimension of the waveguide. A switchable semiconductor arrangement, including a switching semiconductor element and a housing for accommodating the switching semiconductor element, is adjustably mounted in a side wall of the waveguide section and penetrates into the said cavity with a controllable penetration depth for tuning said waveguide section for a desired phase angle shift.

Abstract: A wideband 180-degree digital phase shifter bit is provided which is operable independently of input rf frequency over a predetermined bandwidth of interest. The phase shifter bit comprises a coupled transmission line segment and a pi network segment, with switching means for alternatively connecting the rf input and rf output first to the coupled transmission line segments, and then to the pi network.

Abstract: A bidirectional continuously variable phase shifting element is described for incorporation in a monolithic microwave integrated circuit (a circuit which combines both passive and active circuit elements). The preferred active device for use in the phase shifting element is a variable resistance field effect transistor (MESFET), while the preferred passive circuit element is a short transmission line interconnecting the principal electrodes. A variable phase shift for an RF signal passing through the phase shifting element is obtained by adjusting the gate potential of the MESFET between full conduction and nonconduction. The change in conductivity of the MESFET causes the serial impedance of the phase shifting element to vary from a substantially resistive impedance to a substantially capacitively reactive impedance arrangement, which requires only a single active device, is applicable to frequencies generally above 1 GHz, and provides phase shifts up to 45.degree.

Abstract: A delay line circuit provides variable delay and phase shift to electric signals propagating along the delay circuit. The circuit is formed of a set of varactors constructed either as varactor chips or as a set of mesas upstanding from a gallium arsenide substrate. A ground plane interconnects bottom terminals of the varactor chips while a strip line conductor interconnects top terminals of the varactor chips. In the case of the mesa configuration, a metallized layer covers the regions between the mesas without contacting the base portions of the mesas. The strip line conductor makes contact with the respective mesas via a set of metallic posts upstanding from respective ones of the mesas. Dielectric material may be inserted between the strip line conductor and the metallic layer to position the strip line conductor relative to the metallic layer, which layer serves as a ground plane in a transmission line comprising the strip line conductor.

Abstract: An extra high frequency .pi.-section digital phase shifter apparatus having a diode connected between two identical parallel shunt circuits. The parallel shunt circuits connect to the series inductor/diode circuit at both the input and output and each parallel shunt circuit has inductor connected in parallel with a capacitor and a diode to provide balanced insertion loss at each diode switching state. When the diodes of the circuit are in the forward-biased state they act as closed short circuit switches. When the diodes are reverse-biased, the inductance in the shunt circuit resonates with the diode capacitance to provide a short circuit path to the RF signal at the center frequency of the RF signal at the desired phase.

Abstract: An extra high frequency T-section digital phase shifter apparatus having a pair of back to back diodes connected between the input and output terminals with a parallel circuit connected between the common junction and ground. The shunt parallel circuit has an inductor in parallel with the series combination of a capacitor and a diode to provide a balanced insertion loss at each diode switching state. When the diodes are in the forward-biased state they act as closed short circuit switches and in the shunt circuit, the inductance resonates with the diode capacitance to provide a perfect transmission for the RF signal.

Abstract: A n-bit digitally controlled phase shifter for controlling the phase of an applied signal over the range of 0.degree. to 360.degree. includes n, cascade interconnected phase shifter stages. Each phase shifter stage is formed on a semi-insulating substrate having a pair of field effect transistors and a pair of transmission lines formed thereon. Each field effect transistor (FET), includes a pair of gate electrodes, a drain electrode, and a source electrode, connected in a common (grounded) source configuration. Each transmission line is coupled between a corresponding one of the drain electrodes and a common output port. The lengths of the transmission lines are selected to provide two paths having an electrical pathlength corresponding to a phase shift of .phi..sub.1 or a phase shift of .phi..sub.1 +.DELTA..phi..sub.1 where .DELTA..phi..sub.i is the phase shift increment of the i.sup.th stage. A first one of the gate electrodes of each field effect transistor is fed by the applied signal.

Abstract: Switched line phase shifters are provided with an increased operating frequency range for a given level of phase setting accuracy by providing increased-resolution phase shifters and by translating phase commands in accordance with the center frequency of the signal to be phase shifted.

Abstract: A millimeter-wave electronic scan, phased array antenna in a slotted dielectric waveguide having a semi-insulating core and at least one semi-conducting epitaxial layer. A controller affixed to the epitaxial layer is used to apply a bias voltage thereby varying the conductivity of the layer and influencing wave propagation in the guide to effect beam scanning.

Abstract: A millimeter wave reflection phase shifter employs a fin-line structure within a waveguide network which has a central leg and four arms which together form two symmetric Y-junctions. The fin-line forms a septum within the waveguide and includes a conductive layer having a central gap or slot therein which extends along the leg and into each of the arms. Means for shorting the slot arms disposed at one end of the leg controls the phase shift experienced by a signal propagating through the phase shifter. This phase shifter may provide multiple selectable phase shifts.

Abstract: A millimeter-wave electronic phase shifter in a dielectric waveguide having a semi-insulating dielectric core and at least one semi-conducting epitaxial layer. A controller affixed to the epitaxial layer is used to apply a bias voltage thereby varying the conductivity of the epitaxial layer and influencing wave propagation in the waveguide.

Abstract: A single-pole-double-throw microwave monolithic switch is realized by employing shunt connected field effect transistors interconnected with microstrip transmission lines on a gallium arsenide substrate. A low-pass network, configured with quasi-lumped elements, is used to achieve a 90.degree. phase shift between the transistors and the input point. The FET gate width is selected to yield the appropriate source-drain capacitance, which forms one element of the low-pass network comprising the respective switch output path. Use of this inventive structure yields the bandwidth offered by the conventional shunt switch and the small size achievable in the series switch configuration.

Abstract: A phase modulation circuit to provide at an output terminal an output signal controllably shifted from 0.degree. to 360.degree. relative to an input signal provided at an input terminal includes a first 90.degree. coupler connected between the input terminal and second and third 90.degree. couplers, four gain controllable amplifiers, fourth and fifth 90.degree. couplers and an in phase combiner with its output connected to the output terminal. Two of the amplifiers are connected between the second and fourth couplers. The additional amplifiers are connected between the third and fifth couplers. The fourth and fifth couplers are connected to the inputs of the in-phase combiner. The gain through the various amplifiers is adjusted to control the amount of phase shift through the circuit.

Abstract: A circuit for phase shifting a signal has been described incorporating a four port network containing a plurality of impedances wherein each impedance is provided by a transmission line having a predetermined characteristic impedance and predetermined phase length and wherein an input signal is coupled to the first port, an output signal is coupled to the second port, a first diode is coupled to the third port, a second diode is coupled to a fourth port and means for biasing the diodes to be conducting at first times and nonconducting at second times. The phase shifter circuit overcomes the problem of phase error, amplitude modulation and voltage standing wave ratio over a predetermined frequency range.

Abstract: A phase shifter utilizing a circulator and electronic switches to change the length of a transmission line is disclosed. More specifically, a section of transmission line terminated in a short circuit is coupled to one port of a circulator. Energy exiting the port is reflected by the short circuited transmission line to introduce a phase delay in the signal. A PIN diode is utilized to provide a switchable short across the transmission line to reduce its electrical length thereby reducing the phase delay.

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 alternate-path phase switch has a primary conductive region and control regions which provide alternate paths in gaps formed with the primary region. Switching means, e.g. PIN-diodes, control the potentials on the control regions and select the path followed by microwave radiation. Each path results in a different phase in the output so the device acts as a phase modulator.

Abstract: A digital phase bit is provided for microwave operation, comprising a pair of FET switches and at least three transmission lines. The FETs when operated in a digital switching mode, present a small impedance when on and a high impedance when off. Each of two of the transmission lines exhibits a series inductive impedance over the operating frequency band and shunts a FET switch, two shunt combinations being interconnected by the third transmission line. When the switches are on, the signal path is effectively through the FET switch alone (and not branched) and a reference phase shift is produced. When the FET switches are off, a signal applied to the phase bit branches at each shunt combination. The inductive reactance of the transmission line and the capacitive reactance of the FET switch of each shunt combination then jointly produce a resonantly enhanced reactance over the band, causing a reflection and a maximum differential phase shift.

Abstract: A phase shifter includes three cascade interconnected phase shift stages. Each stage includes a quadrature coupler and a pair of field effect transistors (FET), having a pair of gates, a drain, and a source, connected in a common (grounded) source configuration. The drain of each FET is coupled to an input port of the quadrature coupler to provide two signal paths having an electrical pathlength difference corresponding to a 90.degree. differential phase shift. In the third stage, a length of transmission line is coupled between a drain of one of the FET's and one input port of the coupler to provide a signal path having an electrical pathlength corresponding to a 180.degree. phase shift. An input signal is fed to one of the gates of each FET of the first stage, and voltage level control signals are fed to the second one of gates of each FET of the first stage, to control the amplitude of the signal coupled to each drain.

Abstract: A reflection phase shifter includes transmission-type fractional phase shifters and a reflection-type fractional phase shifter. The fractional phase shifters include PIN diodes and transforming sections for transmission line matching. Three fractional phase shifters provide 45-, 90-, and 180-degree delays. The individual fractional phase shifters are selectably "switched in" by the application of bias signals.

Abstract: A digitally programmable attenuator for high speed and a large dynamic range is constructed with a phase-controlled attenuator for small steps of attenuation and an attenuator of switched resistive pads for larger steps. The attenuators are connected in tandem and actuated combinatorially with the phase-controlled attenuator being switched into operation for the small steps, and the resistive pads being switched into operation for the large steps. A phase-controlled attenuator is constructed to permit adjustment of the attenuator characteristic, and a switched-pad attenuator is constructed to be phase shiftless.

Abstract: A semiconductor memory having an address buffer (10), row decoder (12), word lines (16), bit line (20) and sense amplifier (22) for accessing individual memory cells in an array of memory cells. In order to emulate worst case delays experienced in the word lines in accessing the last cells in the rows in order to prevent the sense amplifiers (22) from reading the bit lines (20) too soon, a tunable delay circuit (30) delays actuation of the sense amplifier. This circuit is divided into a plurality of impedance section with associated parasitic capacitance where groups of sections are bypassed by switching devices such as MOS transistors. The delay of a signal propagating through this tunable delay circuit can be varied by bypassing varying numbers of the sections with the switching devices.

Abstract: A high speed reflectance type phase shifter is described incorporating a wide bandwidth coupler having four ports, two of the ports having a high speed diode coupled thereacross a resistor coupled in shunt across each diode to provide power dissipation at times the diodes are non-conducting and a current driver to provide bias current to the diodes. The invention provides constant insertion loss through the phase shifter during the on state and off state of the diodes corresponding to the two phase conditions of the output signal without affecting bandwidth.

Abstract: A phase shifter has two sections, a gyromagnetic section and a switching section connected in series. The gyromagnetic section provides fine increments of phase shift and the switching section provides larger increments of phase shift.

Abstract: A phase shifting circuit comprising a quadrature hybrid for splitting a source of signals into two paths, with an amplifier in each path and a summing hybrid for recombining the outputs from the amplifiers to produce a resultant signal. Phase shift adjustment is achieved by independently varying the gain control voltage of each amplifier.

Abstract: An adjustable phase shifter for adjustably providing a 360.degree. range of phase shift to RF signals by dividing the RF signals into three equal parts, adjusting the relative amplitudes of the parts of the RF signals and combining the three parts of the RF signals at relative phase angles of 0.degree., 120.degree. and 240.degree..

Abstract: A convolver based on the propagation of acoustic waves at the surface of a piezoelectric solid comprises a piezoelectric substrate, means for exciting two backward-traveling acoustic waves at the frequency f, means consisting of at least two electrodes for collecting the signal at the frequency 2f, the signal being produced as a result of nonlinear interaction of the two acoustic waves. The convolver device is connected to one of the two electrodes by means of a plurality of electrical contacts placed lengthwise and at intervals along the axis of propagation of the two interacting acoustic waves which are representative of the electrical signals applied to the two convolver inputs.

Abstract: Microwave phase modulators are described utilizing three or more hybrid junctions, two of which are phase quadrature hybrids each having one pair of conjugate terminals terminated with switching means and each having one of the remaining terminals connected to a respective terminal of a third hybrid junction. With power in at a third terminal of the third hybrid junction, power out at the 4th terminal of the third hybrid junction can be selectively shifted 180.degree. or switched off by operation of the switching means. Broad band operation is achieved and reflections by the switching means do not have to have a precise phase tolerance as long as they are similar.

Abstract: Disclosed is a millimeter wave bulk effect RF power limiter consisting of a lanar PIN diode formed on a gallium arsenide (GaAs) substrate which also comprises the waveguide structure for RF energy in the 60-300 GHz range. The PIN diode is comprised of a wedge of intrinsic type semiconductor material formed across the top surface of the substrate and having mutually opposing regions of p and n type semiconductor material fabricated in the side edges of the wedge to which is attached planar beam leads. With suitable electrical operating potentials applied to the PIN diode avalanche breakdown occurs at a critical RF power level which acts to limit the flow of RF energy flow in the structure past the location of the PIN diode. Such a structure permits the device to be integrated into the front end sections of receivers utilized in communications, missile guidance and radar systems operable in the millimeter and sub-millimeter frequency range.

Abstract: A four-state phase shifter for UHF waves comprises two O-.pi. phase-shifting elements of planar structure on a common substrate, these phase-shifting elements including a symmetrical and an asymmetrical transmission line which can be selectively coupled in one of two ways by the alternate blocking and unblocking of respective diodes for a relative phase reversal. The two phase-shifting elements are linked by two further transmission lines of different propagation constants which can be selectively activated, again with the aid of diodes, and which may be disposed on opposite faces of the substrate or may form part of a coplanar conductor array on the same substrate face.

Abstract: A complex RF weighter provides an RF output signal controlled in amplitude and phase with respect to an input signal. The input signal is applied to a quadrature hybrid that is terminated with two PIN diodes, one of which is one-eighth wavelength farther from the hybrid than the other. Independent control of the bias on the PIN diodes provides control of the relative amplitude and phase of the output signal.

Abstract: This invention relates to an analog phase shifter for radio frequency signals that employs a hybrid coupler and biased varactor diodes at its reflection terminals. The diodes are operated so that the normalized reactance is unity (equals the coupler's input impedance) at an intermediate frequency which may be the geometric mean of the end frequencies of a broad bandwidth. The couplers are cascaded in tandem for a 360.degree. phase shift. A balanced configuration of hybrid couplers is used for the phase shifter.

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 phase shifter comprises a transmission line having a second terminated transmission line extending therefrom. A single diode is coupled across the second transmission line. The diode is switched between two operating states which changes the effective electrical length of the second transmission line and introduces a phase shift to a signal propagating in the first transmission line.

Abstract: A high frequency diode digital phase shifter element of the transmission line type has a capacitor coupled serially in a primary transmission line conductor. Two shunt switchable elements are coupled by the series capacitor. The switchable element includes short-circuitable lengths of transmission line whose effective electrical lengths can be varied by simultaneously changing the biased state of shunt mounted PIN diodes.

Abstract: A reciprocal phase shifter for optically controlling the phase of microwa millimeter, and submillimeter wavelength electromagnetic energy includes a source of light and a waveguide which comprises an interaction material for absorbing the light and forming a plasma of electron-hole pairs within the material. The plasma interacts with a traveling wave in the waveguide. The speed at which the wave propagates changes in the interaction region and thereby changes the phase of the wave.

Abstract: The inverted microstrip phase shifter consists of a substrate having at least one diode and biasing circuitry connected to one side and at least one center conductor connected to its opposite side. The substrate side containing a center conductor is enclosed within a hollow case so as to form an rf transmission line. The parameters for the biasing circuitry are selected by performing a computer optimization of the chain matrix equivalent expression for the voltage transmission coefficient.

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 phase shifter comprises a segment of transmission line and a reentrant transmission path segment. Each phase shift "bit" utilizes only a pair of diodes to switch in a transmission path which provides the desired phase shift. The phase shifter is of relatively small size and is relatively inexpensive.

Abstract: Continuously variable phase shift is obtained by means of two variable phase shifters (20,21) located in two separate, switchable parallel wavepaths (18, 19). The first phase shifter (20) is variable over, at least, the range between zero and 180 degrees. The second phase shifter (21) is variable over, at least, the range between 180 degrees and 360 degrees. Switching means (22, 23) are provided for switching the signal to one or the other phase shifter. A control circuit (16) simultaneously causing the phase shift through the two phase shifters to vary in the opposite sense. When maximum phase shift is reached, the control circuit switches the signal from one phase shifter to the other, thereby providing continuously variable phase shift through the network.

Abstract: A slow wave transmission line is compatible for fabrication on a substrate having an epitaxial layer by creating under the transmission line a buried layer, thus allowing voltage control of the electrical length of the line.

Abstract: An electrical phase shifting circuit element of the reflection type including a quadrature coupler branch network, a matched pair of selectively coupled transmission lines and an electrical switching element corresponding to each pair of transmission lines, all being separated distributively from each other and a ground plane by a dielectric material, is disclosed. One end of one transmission line of each pair is connected to a corresponding phase splitting port of the quadrature coupler and another end of the other transmission line of each pair is coupled to the switching element which is preferably a pin diode. The pin diodes may be governed by a common switching signal to electrically connect and disconnect the another ends of the other transmission lines to the ground plane.

Abstract: The invention involves in-phase power splitting from an input into separate pairs of paralleled input variable circuits which may be linear amplifiers or linear controlled attenuators. The outputs of these circuits feed the input branches of a pair of 180.degree. hybrid circuits, the outputs of those hybrids providing the inputs of a 3 db quadrature coupler. An output of this coupler then provides the overall output which is shifted in phase with respect to the original input as a function of the gain control signal applied differentially between the variable circuits of the aforementioned pairs as the cosine of the desired phase angle in respect to the first pair of circuits and in accordance with the sine of the desired phase angle at the control terminals of the second pair of circuits.