Abstract: A fully monolithic solid state device compatible with standard semiconduc processing for amplifying radio frequency (RF) microwave and/or millimeter wave signals is disclosed. The device includes an input microstrip transmission line which capacitively couples an input RF signal to input underlying grating fingers which, in turn, mode-couple the signal to an interaction grating region by way of an input finger taper region. The RF is amplified in the interaction grating region through its interaction with a space charge wave. Then the amplified RF signal is mode-coupled to output underlying grating fingers by way of an output finger taper region before it is capacitively coupled to an output microstrip transmission line.

Abstract: A nuclear magnetic resonance (NMR) signal acquisition apparatus includes a cylindrical array of overlapping coils. Coupling of currents between coils due to re-radiation of received signals, in particular noise currents, is reduced by presenting a high impedance to each coil, thereby reducing the current circulating in each coil. A PREDAMP circuit is disclosed which utilizes the input impedance of a preamplifier, transformed through a quarter-wavelength transmission line segment, to achieve the high input impedance for the coil. As a result, multiple images, each with a high signal-to-noise ratio (SNR), can be simultaneously obtained. A method is disclosed for combining the multiple images into a composite image with optimum SNR, taking into account the phase shifts between the images resulting from the spatial orientation of the coils.

Abstract: A gallium arsenide MESFET amplifier circuit employing a parallel feedback network having first and second transmission line section filtering networks connected on either side of a series R-C-R circuit. In one optimized embodiment, the transmission line sections each include low and high impedances unequal in length to one-quarter wavelength. The use of two discrete resistors, together with the filtering networks to eliminate thermal noise generated by the resistors, provides optimum gain, low noise, and stable operation over a wide range of microwave frequencies.

Abstract: The nonlinearity of the frequency response of a solid state power amplifier (SSPA) is obviated by effectively operating the SSPA at the 1 dB compression point, where the nonlinearity does not exist, and controllably reducing, downstream of the SSPA, the power output produced by the SSPA to the level required by the link. In particular, the output is reduced by controllably inserting a relatively thin tapered blade of ferrite material into a waveguide coupling section downstream of the SSPA. Preferably the ferrite material is comprised of a robust carbonyl steel of sufficient thickness to withstand the heat induced in the course of its absorbing microwave energy at the SSPA output, while being of a narrow or thin configuration and oriented for insertion into the absorbing section of waveguide so as to not effectively alter the characteristics of the signal profile of the electromagnetic wave.

Abstract: A high-frequency power synthesizing apparatus having a plurality of distributors arranged in a plurality of stages, a plurality of amplifiers which are supplied with outputs from a final stage of said power distributors and which amplify these outputs to a predetermined level, and a power synthesizing unit including initial-stage power synthesizers supplied with outputs from said amplifiers and a final-stage synthesizer which outputs power to an external load. The final-stage power distributors and the initial stage synthesizers are constituted by 0.degree.-hybrid modules. The output level of each amplifier is regulated and made constant by being compared with a predetermined level. The output levels of the amplifiers can be displayed on an external display.

Abstract: An input signal for a travelling wave or distributed amplifier having input and output transmission lines is supplied to one end (1) of the input line and an output signal is derived from one end (4) of the output line. Conventionally, the other end (2, 3) of each line is terminated in a respective matched load, but three ports of the amplifier may be employed. The travelling wave amplifier may be used to replace a circulator (CIRC, FIG. 2) in an FMCW radar having a single transmitting/receiving antenna (ANT) (TWAMP1, FIG. 3), to replace a directional coupler (DC) for supplying a local oscillator signal to a mixer (MXR) (TWAMP2, FIG. 4), and in combination with a mixer diode (D) to form a mixer amplifier (TWAMP3, FIG. 3), giving the possibility of the larger-scale integration of RF circuits.

Abstract: A distributed FET amplifier comprising an array of FET elements each having a gate terminal, a drain terminal and a source terminal. The gate terminals of the adjacent FET elements are connected by a first inductor, and the drain terminals of the adjacent FET elements are connected by a second inductor. Between the source terminals of each of the FET elements and the ground is connected a parallel circuit comprising a capacitor having a capacitance greater than the gate-source capacitance of the FET element and an impedance element connected in parallel to the capacitor for grounding the direct current. A bias voltage supply circuit for supplying a bias voltage to such as distributed amplifier is also disclosed.

Abstract: An amplifier includes a single-gate FET and a dual gate FET in parallel interconnection. A temperature sensing circuit supplies a temperature-dependent bias voltage to the G.sub.2 gain control gate of the dual gate FET to counteract the temperature-dependence of the amplifier FETs thereby providing gain stability in the presence of temperature variations.

Abstract: In order to supply a d.c. bias to the drain electrodes of MESFETS (1-4) in a distributed amplifier operating in the 500 MHz to 20 GHz or above, a d.c. source (15) is connected to the drain line (5,9,11,14) via a feed component (16) which comprises a ferrite bead (17) having an axial aperture (18). A coil (19) comprising, for example, four turns of 20 micron gold wire is wound on the bead in toroidal fashion. The bead may be of the kind which is used for low-frequency interference suppression or for encircling the emitter lead-out wire of a bipolar transistor operating in the lower megahertz range. At these relatively low frequencies in the conventional use of the bead, the bead material will exhibit low magnetic losses and high permeability. However, in the present invention, due to the microwave signal in the coil, the bead operates over a frequency band which is many times higher than its normal operating band. At these high frequencies the bead material exhibits quite large losses.

Abstract: A wide band amplifier for operation at very high frequencies, for example in the 20 MHz to 50 GHz range comprises a MESFET distributed amplifier (22) having a gate and a drain transmission line, a first hybrid circuit (18) to apply a first and second input signal to opposite ends of the gate transmission line, and a second hybrid circuit (26) connected to opposite ends of the drain transmission line to receive and combine first and second output signals from the drain transmission line to provide an amplified output signal. The use of two input signals travelling in opposite directions along the gate transmission line increases the gain which can be achieved in the distributed amplifier and reduces the noise component of the output signal. It is particularly useful for enhancing the performance of a distributed amplifier containing only a few MESFETs.

Abstract: A monolithic semiconductor having an on-chip DC biasing including a plurality of series connected spiral inductors connected between the respective biasing and the semiconductor circuit. The spiral inductors provide a low resistive path for the DC biasing while also having a high inductance for isolating the RF signal from the bias sources, thereby improving the low frequency response. The capacitance associated with the individual spirals, however, is significantly less than the capacitance associated with a single spiral inductor having an equivalent inductance of the small series connected spirals; thus the higher frequency response is not degraded while the low frequency response has been improved.

Abstract: A lower-noise microwave amplifying circuit for use in a lower-noise converter includes a metallic conductor for use in performance adjustment. The metallic conductor projects from the microstrip line and is provided near a bendable connecting portion between an input coaxial rod in a coaxial waveguide conversion portion and a microstrip line for constructing one portion of an amplifying circuit. Therefore, the lower-noise microwave amplification circuit is easily adjusted for improving the basic characteristics such as input VSWR or the like and is simpler in construction.

Abstract: For reduction in occupation area, there is disclosed a microwave device fabricated on a semi-insulating substrate and comprising a passive component area where a plurality of passive component elements are formed and an active component area where at least one active element is formed, the passive component area having a film overlain by a dielectric film and a strip conductor extending on the dielectric film, wherein the film and the strip conductor are formed by a superconductive material, so that the dielectric material is decreased in thickness by virtue of the strip conductor of the superconductive material.

Abstract: Disclosed herein is an N-way, broad band planar power divider/combiner circuit for dividing or combining RF signals which includes a tapered strip of electrically conductive material having a plurality of conductor fingers which define a plurality of ports at the wide end of the taper, and having a narrow end which defines single port. The tapered metal strip is mounted onto a dielectric slab, and isolation resistors connect adjacent fingers. A single RF signal can be fed into the single port which will be divided into a plurality of signals of equi-amplitude and equi-phase. Conversely, a plurality of RF signals can be fed into the ports at the wide end which will be combined into a single signal.

Abstract: Disclosed is a power divider/combiner using two parallel plate radial transmission lines having parallel plate spacing of less than .lambda./2 and which operates in a higher order mode, preferably the first higher order circumferential mode TE.sub.11. High isolation between amplifiers coupled to the radial transmission lines at their circumferences is achieved by coupling an arrangement of circulators between the amplifiers and the radial transmission lines. This isolation arrangement reduces the effects of any spurious signals that are generated by means such as imperfections and imbalances in any active devices coupled to the radial line and permits de-energizing amplifiers as desired for lowering power output without degrading performance.

Abstract: Disclosed is a parallel plate radial transmission line having parallel plate spacing of less than .lambda./2 and which utilizes a specific higher order mode, preferably the first higher order circumferential mode. Undesired modes are suppressed by mode supression slots formed in one or both of the parallel plates and which are oriented parallel to the current flow lines of the particular mode that is used. These slots have a negligible effect on the mode being used but they couple out other modes that are generated by means such as by imperfections and imbalances in any active devices coupled to the radial line. A centrally located feed is used to launch circularly polarized energy of the TE.sub.11 mode in the particular circumferential mode in the radial line. The feed may also receive circularly polarized energy of the particular circumferential mode in the radial line, linearly polarize that received energy and conduct it in the TE.sub.11 mode.

Abstract: A low noise microwave amplifier wherein a length of a pair of broad or wider walls inside the rectangular waveguide is shortened at least near a portion where a probe for introducing a microwave signal into the amplifying portion is provided. A cutoff frequency of the waveguide near the portion where the probe is provided is raised and comes to 80% to 90% of the lower limit of the frequency of the desired amplification band of the amplifier. An input microwave having a frequency component below the cutoff frequency is prevented from flowing into the amplifier, whereby the generation of oscillation is effectively prevented.

Abstract: A microwave power combining FET amplifier includes T-type input and output branch circuits 13, 14 for power splitting and combining, and interstage matching circuits 6a, 6b laterally connected at their mid-points a, b by a resistance circuit 15 which absorbs odd propagation mode waves reflected back from the output combiner due to non-uniformities between the post-stage FETs 4a, 4b.

Abstract: The present invention provides a modified distributed amplifier which is capable of providing push-pull operation without the loading losses of conventional push-pull combining. The modified distributed amplifier comprises a distributed amplifier configuration and with signal inverting means, such as a wide bandwidth transmission line transformer, interconnected into both the input and output lines. The signal inverting means are most effectively placed at the electrical centers of the lines, but may be placed at any positions in the individual lines to produce optimum performance to specific applications. The separate segments of the distributed amplifier separated by the signal inverting means operate in opposed phase but the signals output to the load add in phase thus providing push-pull operation.

Abstract: A finline structure comprises a dielectric substrate-mounted circuit disposed within a waveguide having on the substrate integrated distributed capacitance elements at least partially formed by laterally separated metallization layers. Thin-film construction techniques may be employed in construction. In general, the distributed capacitance elements permit the biasing of a plurality of circuit elements in a finline transmission medium. In selected structures, r.f. continuity is effected between traces and metallization layers while maintaining d.c. isolation. Examples are described of circuits which can incorporate an integrated capacitor, including but not limited to detectors, r.f. modulators, r.f. attenuators, amplifiers, and multipliers. According to the invention, a plurality of elements, as well as multiple port elements, may be selectively biased while retaining d.c. isolation and r.f. continuity.

Abstract: A multifunction monolithic microwave integrated circuit composed of a pluity of dual gate FET amplifier sections connected between a pair of transmission lines which are adapted to receive one or two input signals. The circuit can be configured, by selective external connections and biasing voltage levels, to function in a number of different modes, such as an amplifier, a mixer, modulator, a variable amplifier, an attenuator, a temperature compensation chip, a frequency multiplier and a phase shifter.

Abstract: A distributed amplifier includes a plurality of field effect transistors, each having gate, drain, and source electrodes, successively coupled between an input terminal and an output terminal. The gate electrode of each one of successively coupled FETS is coupled to the input terminal through a corresponding one of a plurality of capacitors and selected ones of the drain electrodes of the FETS are coupled to the output terminal through one of a corresponding second plurality of capacitors, with said capacitors being coupled to an output coupling means comprising a plurality of transmission line sections. By providing the second plurality of capacitors to couple the drain electrodes to the output terminal, the output impedance of each one of the field effect transistors is concomitantly increased thereby permitting the periphery of the transistors to be correspondingly increased and thereby providing increased output power and gain from the amplifier circuit.

Abstract: A feed-forward microwave amplifier arrangement is disclosed havaing an error-detecting loop including a main amplifier branch and a phase-shift branch, as well as an error-canceling loop including an auxiliary amplifier branch and a phase-shift branch. A temperature compensating arrangement including a ferrite slab centrally mounted in a stepped rectangular waveguide is provided in the phase-shift branch of the error-canceling loop. The temperature compensating arrangement has a phase versus temperature characteristic similar to that of the auxiliary amplifier. An additional ferrite temperature compensating arrangement, having a phase versus temperature characteristic similar to that of the main amplifier, may be provided in the phase-shift branch of the error-detecting loop.

Abstract: A distributed circuit includes a plurality of field effect transistors (FETS), each one of such FETS having gate, drain and source electrodes, with a first portion, or a first channel, of such FETS having gate electrodes and drain electrodes successively coupled between a first input terminal and an output terminal, and a second like portion or a second channel of such FETS having gate electrodes and drain electrodes successively coupled between a second input terminal and said output terminal. Separate bias circuits are provided to the input electrodes of the first and second channels. Bias signals fed to the bias circuits and coupled to the input electrodes place the FETS in an "on" state to provide gain to r.f. input signals fed thereto, or in a "pinch-off" state to isolate r.f. signals fed to the input electrodes of the FETS. Accordingly, a 2.times.1 switch or a two way active r.f. combiner which provides gain to a signal is provided.

Abstract: The invention relates to a low noise amplifier for use at microwave frequencies which may be fabricated using integrated circuit techniques. In accordance with the invention, critical components are made adjustable so as to simplify the design process and manufacturability of the amplifier. A two stage low noise amplifier is disclosed in which TEE networks are used as input and output networks in each stage, and in which one element of each TEE includes an adjustable spiral inductor. The value of each adjustable spiral inductor may be adjusted by removal of one or more air bridges disposed along the inner turn of the inductor. This permits one to "tune" the amplifier and optimize its performance.

Abstract: A radio-frequency (rf) power combiner or divider structure containing distributed amplifier components and having broadband operating characteristics, and operable with net gain or practically no insertion losses. The divider structure includes an input transmission line having series-connected impedances that interconnect with active devices, such as field-effect transistors to form a practically lossless line. The active devices provide gain between distributed points in the input transmission line and distributed points in multiple output transmission lines, which are similarly structured as series-connected impedances. Each output transmission line supplies one of the divider outputs. In the combiner form of the device, there is a single output transmission line and multiple input transmission lines, coupled to the output line in a distributed manner by active devices.

Abstract: A DC bias line module for use with an r.f. signal processing apparatus which incorporates terminating resistors, in lieu of capacitors, that are connected to the r.f. line.

Abstract: An internally matched power amplifier including an input terminal for receiving an input signal and an output terminal; a plurality of semiconductor devices connected with the load electrodes in series; transmission means for coupling the load electrodes of neighboring devices in the series and establishing an internal impedance match; the last device in the series having its other electrode connected to the output terminal; the first device in the series having its control electrode connected to the input terminal and its other load electrode connected to a common conductor and having a predetermined d.c. bias level and a predetermined signal voltage level between its control and its other electrode; first means for setting the control means of each device but the first in the series to the predetermined signal voltage level and second means for biasing the control electrode of each device but the first in the series to the predetermined d.c. bias level.

Abstract: A microwave matching circuit, having a main line (for transmitting a high frequency signal) and a stub, formed close to the main line (for matching the input terminal of the high-frequency signal and the output terminal of the main line) includes a capacitor, for absorbing unnecessary components at the main line and other output terminals, connected between the main line and the stub.

Abstract: A broadband distributed amplifier comprised of a plurality of field effect transistors whose gates are connected to junctions between serially-connected inductors forming a gate transmission line, whose drains are connected to junctions between serially-connected inductors forming a drain transmission line, and whose sources are connected to ground. The distribution of the amplifier stages along the gate and drain transmission lines is effected such that these transmission lines are periodically loaded by their own impedances and by the transistor gate and drain capacitances, thus forming artificial lines, and such that a microwave frequency input signal applied to the input of the gate transmission line effects the production of an amplified microwave frequency output signal at the output of the drain transmission line. The gate and drain transmission line output and input, respectively, are terminated by loads.

Abstract: A distributed balance frequency multiplier has a transmission line that is configured using lumped elements having connection points for inputting signals. Connected to each connection point is the output from a non-inverting amplifier which does not invert a signal applied thereto. A second transmission line is configured also using lumped element techniques and has connection points for receiving an inverted amplified signal whose odd harmonics are 180.degree. to the non-inverting amplified signals. The signal that is to be amplified is carried to both the non-inverting and the inverting amplifier by a third transmission line that also uses lumped elements distribution techniques to create a transmission line. The output of the first transmission line and the second transmission lines are tied together so that the odd harmonics due to the inverting amplification stages cancel and the even harmonics are additive, thereby achieving an effective multiplication of the input signal.

Abstract: A microwave amplifier that both multiplicatively and additively amplifies microwave frequency signals. The amplifier, herein coined a matrix amplifier, is a distributed amplifier with two or more tiers (rows) of transistors. Each tier has a plurality of transistors which additively amplify the signal entering that row of the amplifier, and each row multiplicatively amplifies the output of the previous row. The gates of the transistors in each row are sequentially coupled to an input transmission line having a series of transmission elements. The outputs of all the transistors from each row are sequentially coupled to the input transmission line of the next tier, except that the outputs of the last tier are coupled to an output transmission line for transmitting the output of the amplifier to an output node. Furthermore, each transmission lines has (1) at least one line termination at one of its ends for absorbing signals incident on that end of the transmission line, and (2) biasing means for d.c.

Abstract: An amplifying circuit for amplifying a bipotential input signal, including an insulating housing having a conductive input contact mounted on the housing and adapted to engage a human body so that the bipotential input signal applied to the contact; a lead amplifier having inverting and non-inverting inputs, one of which is coupled to the input contact, and an output; first and second diodes connected in parallel inverse polarity across the inputs of the lead amplifier; third and fourth diodes connected in parallel inverse polarity from the inverting input of the lead amplifier to a circuit common potential; and an output resistor connected from the inverting input to the output of the lead amplifier. Portions of the input contact are surrounded by a voltage drive shield connected to the output of the lead amplifier.

Abstract: A field effect transistor microwave circuit device includes first and second field effect transistors having common source connections with a pair of coupled transmission lines connecting the drain of a first transistor to the source of the second transistor and the source of the first transistor to the gate of the second transistor. The cross coupled transmission lines function as a balun between the transistors. The device is formed in III-V semiconductor and has an increased operating range in microwave frequencies. In alternative embodiments, the balun is connected to the circuit output thereby permitting the cascading of a plurality of FET devices. The balun can be integrated into the device structure or connected as a discrete element in a hybrid circuit arrangement.

Abstract: An arrangement for coupling waveguide modes between two waveguides via a semiconductor element. The two waveguides each have a short-circuiting end wall and a common side wall constituting a common partition wall between the waveguides so that the two waveguides extend parallel to, and overlap one another at least over a partial length where they are separated from one another by the common side wall. The common partition wall is provided with a coupling aperture and the semiconductor element is inserted into the coupling aperture between the two waveguides and is in ground contact with the common partition wall. The semiconductor element has two connectng arms, one connecting arm extending as a coupling probe into one of the waveguides and the other connecting arm extending as a coupling probe into the other waveguide.

Abstract: A travelling-wave transistor structure (50) with the input and output transmission lines (54,58) terminated with unmatched impedances (70,72,74;80,82,84) to improve high-frequency response by reflection and phase shift to provide constructive interference is disclosed. Preferred embodiments include a .pi.-gate (52,56) MESFET structure travelling-wave transistor with many periodically spaced gate feeding fingers (56) connecting gate (52) to gate transmission line (54) which parallels gate (52). This provides a compact structure and has large advantages at millimeter wave frequencies. Source (60) may be grounded by vias (61) or may pass over gate transmission line (54) by air bridges to a ground on the same surface as the MESFET.

Abstract: A structure for extra-high-frequency circuit modules, to take advantage of the low losses and convenience of assembly of waveguides, and at the same time to take advantage of the ease of tuning of microstrip lines. Each module is adapted to be conveniently connectable to others in a cascade arrangement, and each presents a waveguide interface to adjacent modules. If a module is to contain an active device, such as an amplifier, the module incorporates a microstrip section and two transition sections to couple the microstrip section to the waveguides at input and output. The microstrip section is easily tunable and is easier to couple to the active device.

Abstract: An RF power splitter-combiner for use in an amplifier system of the kind requiring both RF power splitting and RF power combining, comprising: RF splitter means containing a top and bottom wall, splitter input means centrally located therein and a plurality of splitter output means, said plurality of splitter output means being spaced a predetermined radial distance from and evenly angularly spaced about said input means; RF combiner means, said combiner means having a top and bottom wall, a plurality of input means and an output means, said input means being spaced a predetermined radial distance from and evenly angularly space about said output means; said splitter means containing an internal chamber and having a plurality of circular ridges and channels located in said splitter chamber concentric of said splitter input means; said combiner means containing an internal chamber and a plurality of circular ridges and channels located in said combiner chamber concentric of said combiner output means; said rid

Abstract: In a circuit arrangement comprising a three port isolator (21) which has input, output, and dummy ports (33, 22, and 23), an admittance element (41 to 43) is connected at a position or positions selected between the input and the output ports, between the output and the dummy ports, and between the dummy and the input ports. When the isolator comprises a strip line conductor having branches connected to the input, the output, and the dummy ports, the admittance element may be an extension or extensions of the branches. The output port is connected to an amplifier (14) directly or through an inductance element (34). The connection of the admittance element makes it unnecessary to connect a matching circuit which is otherwise essential between the isolator and the amplifier.

Abstract: A high efficiency RF power amplifier is disclosed in which a field effect transistor is operated in a class F mode. A third harmonic quarterwave open circuit transmission line stub having a Z.sub.O adjusted to provide capacitance series resonant with transistor inductance at the second harmonic is coupled to the transistor output lead to produce a low impedance at the channel drain of the transistor. Parallel resonance of the transistor die capacitance and interconnect inductance coupled to ground by the transmission line produces a third harmonic high impedance at the channel drain. Further lowpass output matching circuitry provides a constantly increasing impedance magnitude from the transistor die to the load and provides load mismatch isolation to the second and third harmonic impedances at the channel drain.

Abstract: A microwave amplifying apparatus includes a waveguide which is shorted at one end and supplied with a TM mode or a TE mode signal, a pickup probe mounted on the waveguide for converting the signal into a TEM mode signal, and microstrip lines and field effect transistors, or amplifier elements, for amplifying the TEM mode signal. A matching device is arranged on the shorted waveguide adjacent to an incidence side with respect to the pickup probe while an input terminal of the first-stage amplifier element is directly interconnected to an output terminal of the pickup probe. The device is, therefore, free from a signal loss otherwise developed between the pickup probe and the initial-stage amplifier element. The matching device consists of three conductive rods which are spaced a quarter-wavelength distance from each other, and three lock nuts for fixing the conductive rods.

Abstract: Radially fed microwave signal combiner/distributor apparatus comprising a central coaxial connector which is coupled via radially extending paths to several circumferential coaxial connectors which are equiangularly disposed on the circumference of a circle surrounding the central connector, the apparatus including a generally discoidal microwave transmission cavity through which the paths extend, which cavity communicates at the center thereof with the central coaxial connector and which cavity communicates at the circumferential periphery thereof with the circumferential coaxial connectors via a conductive annulus, which annulus is spaced away from the internal circumferential periphery of the cavity, and to which annulus the inner conductors of the circumferential coaxial connectors are electrically connected at locations equiangularly spaced around the annulus.

Abstract: A cavity resonator coupling type power distributor/power combiner can be used as a distributing amplifier or a combining unit. A first cavity resonator, having a single coupling terminal, and a second cavity resonator having a plurality of coupling terminals, are coupled by a coupling window or a coupling rod. As a result, a wide bandwidth of microwave electric power can be distributed or combined.

Abstract: A programmable attenuator includes a plurality of field effect transistors (FETS) arranged together to provide an attenuation network. Each one of the FETS has a plurality of cell portions, each cell portion having drain, gate and source regions, the source and drain regions of the cell portions being connected in parallel. A first selected portion of the gate regions of each one of said FETS is connected to a gate electrode. A second selected remaining portion of the gate regions of each one of the FETS has the gate regions thereof isolated from the gate electrode. A signal fed to the gate electrode of each FET is distributed to the connected gate regions of each field effect transistor. In response to such signal, the total drain-source resistance of such FET is changed between a predetermined low value and a predetermined high value, with the resistance of the predetermined high value being determined, in part, by the number of such isolated gate regions.

Abstract: A high-frequency amplifier device according to this invention comprises a high-frequency amplifier portion, a high-frequency input portion which is formed of a waveguide and which can transmit polarized signals orthogonal to each other, two detector portions which are inserted in the waveguide of the input portion and which respectively and independently detect the polarized wave signals orthogonal to each other, an irreversible circuit to which the polarized wave signals detected by the detector portions are individually input and which selectively and switching delivers one of the polarized wave signals to the high-frequency amplifier portion and returns the other polarized wave signal to the input portion, and a switching control mechanism for switching and controlling transmitting directions of the irreversible circuit in response to a control signal externally applied.

Abstract: A single circuit which provides forward biasing, input impedance matching and voltage input limiting to a transistor which has a source, gate and drain terminal is presented. Biasing, input matching and limiting for a transistor is accomplished using two inductor coils, five crystal diodes, a positive voltage source, and three resistors. The forward biasing is achieved using three resistors, and the third, fourth and fifth crystal diode. The third resistor connects the drain terminal of the transistor to the positive voltage source. The second resistor connects the junction between the third resistor and the drain terminal to the transistor's gate terminal. The fourth and fifth crystal diodes are connected in series between the source terminal and the common electrical ground. The first resistor and third diode are connected in parallel between the transistor's gate terminal and the common electrical ground.

Abstract: A waveguide power combiner or splitter (divider) includes a common waveguide having an axis skewed relative to the axes of a line array waveguides. A sectoral parabolic reflector is oriented with its focus at a port of the common waveguide with its axis parallel with the axes of the waveguides of the array for reflecting signals from the focal point to create a locus of constant phase at the ports of the waveguide array, whereby signal power originating at the common waveguide is divided equally among the waveguides of the waveguide array. A waveguide power amplifier includes a power splitter as described above, and an amplifier module located in each waveguide of the waveguide array to amplify the power therein to produce amplified signal in an output waveguide array. The amplified signals from the amplifier modules are combined by a second reflector driven by the output waveguide array and reflected to a common output port.

Abstract: A metal partition wall is placed inside a waveguide without ridge or the like and has an aperture in which a GaAs-FET is located, so that the input and output are coupled only through this GaAs-FET. The input and output terminals of the GaAs-FET are coupled through L-shaped coupling to the waveguide. An amplifier thus constructed has a high gain and is best adapted for power, while because the metal partition wall also serves as a heat sink.

Abstract: A broadband, monolithic integrated-circuit power divider/combiner circuit utilizing gallium arsenide field-effect transistors configured as distributed amplifiers. Two distributed amplifiers include a common merged transmission line element which divides/combines the input signal(s).

Abstract: A broadband microwave recursive filter that provides sharp transitions in the frequency domain between adjacent stop and passbands comprising a signal input node; a signal output node; a filter circuit connected between the signal input node and the signal output node for providing a signal flow therebetween which has a predetermined frequency bandwidth characteristic; a microwave transistor circuit, with the microwave transistor circuit being band-limited to provide gain in only a restricted window of frequencies within the predetermined frequency bandwidth and connected for providing amplification to signals flowing in the filter circuit between the signal input node and the signal output node while suppressing out-of-window signals resulting from design approximations.