Abstract: A Doppler radar module constructed using micro-stripline technology is used in motion sensors and includes a local oscillator stabilized with a dielectric resonator that feeds a microwave antenna via a mixer that is connected in series. The transmission signal is emitted from the microwave antenna and is reflected back from an object where it is received by the antenna and forwarded to the mixer. The mixer mixes the reflected signal with a portion of the oscillator signal to form a Doppler signal.

Abstract: A dual channel monopulse transceiver is described for use at millimeter wavelengths and for the detection of targets for vehicle collision avoidance. A microstrip antenna is located on one side of a plate and a transceiver microstrip circuit coupled to the antenna is located on the other side of the plate. The transceiver includes a reflective balanced mixer, an isolated balanced mixer and a hybrid circuit for connecting the mixers to antenna feed points. Sum and difference signal generating circuits are employed to provide single and split antenna beams for the detection of targets.

Abstract: The input probe of an LNB for commonly receiving clockwise and counterclockwise circularly polarized waves includes a rectangular microstrip patch, with the length of one edge of it being .lambda..sub.g /4, which is installed at the center of an annular strip shaped ground pattern, with a feed horn being disposed at the side opposite to a substrate. Four input probes are installed adjacently to the respective edges of the rectangular microstrip patch. The two pair of the input probes which are installed adjacently to the respective edges of the rectangular microstrip patch are respectively commonly connected to first and second feed lines. With this arrangement, the length of one input probe relative to that of the other one shows a difference of .lambda..sub.g /4.

Abstract: A transducer and a mixer with a double-balanced output according to the current invention are capable of frequency conversion in a microwave band with low distortion. The transducer or the mixer has symmetry of wirings. One side of a printed circuit board has branched strip lines and a single strip line whose base portion serves as an RF input terminal, and the other side of the printed circuit board has twin-branched ground strips and a bridge-shaped ground strip. The combination of the branched strip lines and the twin-branches strips, and the combination of the single strip line and the bridge-shaped ground strip serve as a transducer. One pair of diagonal terminals of the symmetrical diode ring is connected to the base portion of the branched strip lines. The other pair of diagonal terminals is connected to the tip of the single strip line. The diode ring is connected to a transducer. One winding thereof is supplied with a local oscillator.

Abstract: A routing barium-ferrite tuned resonator filter integrated with an image-enhanced, single-balanced mixer. The barium-ferrite tuned resonator filter is preferably a four-sphere barium-ferrite tuned preselector which is integrated with a harmonically mixed, image-enhanced, single-balanced mixer to provide a high level of dynamic range in a harmonically mixed front end. An input resonator of the preselector in combination with a dual PIN diode switch switches low-frequency input signals (e.g., 0 to 26.5 GHz) to a low-frequency output. For high-frequency input signals (e.g., 26.5 to 50 GHz), the four-sphere barium-ferrite tuned preselector is combined with the image-enhanced, single-balanced mixer which incorporates a GaAs monolithic diode bridge integrated circuit. This provides a front end component of a high-performance portable spectrum analyzer.

Abstract: A radio frequency millimeter-wave signal antenna and mixer system includes a dielectric substrate having a generally planar upper surface, and a ground-plane layer of conductive material disposed below the upper surface. This ground plane layer includes a plurality of spaced-apart low conductivity sections or windows to allow passage therethrough of radio frequency signals received at a surface of the substrate. A plurality of antennae are disposed on the upper surface of the substrate, with each antenna being positioned over a respective one of the windows in the ground-plane layer. A plurality of mixers are also disposed on the upper surface of the substrate, each adjacent a respective antenna for receiving radio frequency signals therefrom and for producing intermediate frequency signals.

Abstract: The present invention provides a high frequency transformer capable of stable operation from DC to high frequency. Additionally the present invention provides a mixer with low insertion loss and low distortion, in which a common mode choke is removable from an input portion thereof. To form the stable high frequency transformer according to the present invention, a short circuiting pattern couples two strip lines together to form a U-shaped pattern on a printed circuit board and a lead wire is insulatedly coupled to each strip line and short-circuited at the tip of the U-shape. According to the present invention, a local oscillator is connected to a first port of the high frequency transformer, a diode switch is connected to a second port of the high frequency transformer, thereby serving as an IF output terminal, and a third port is formed at the short-circuiting pattern, thereby serving as the RF input terminal.

Abstract: The present invention provides a monolithic superheterodyne detector pixel operable to receive a radio frequency (RF) signal at millimeter wavelength and produce a video output signal with many orders of improved sensitivity when compared with the prior art. This sensitivity improvement is achieved by translating the received RF signal to a intermediate frequency (IF) signal before detection of the video signal. At the lower frequency of the IF signal, monolithic amplification circuitry can be fabricated more easily to provide necessary gain than would be achievable if simple amplification of the RF signal were attempted. Detector pixels constructed in accordance with the invention each contain an antenna for receiving the RF signal. Local oscillator (LO) signal circuitry likewise apply an externally generated LO signal to the pixel. The RF signal and LO signal are then applied by interconnecting conductors to appropriate mixer means to produce the IF signal.

Abstract: A bandpass filter, having an input port and an output port, comprises a first microstrip split-ring resonator coupled to input port, and a second microstrip split-ring resonator coupled to the first microstrip split-ring resonator, and coupled to the output port. A lumped or distributed capacitance is disposed between the first microstrip split-ring resonator and the second microstrip split-ring resonator.

Abstract: In order to reduce size and facilitate incorporation into planar multi-layer microwave integrated circuits, a microwave hybrid, specifically a Magic-Tee, is formed using microstrip circuit elements and aperture coupling. The Magic-Tee comprises a ground plane interposed between dielectric printed circuit boards. The outermost surface of one of the boards carries a Tee circuit comprising microstrip branch arm conductors with a microstrip conductor projecting transversely from its middle, the Tee junction, to form the leg of the Tee. The outermost surface of the other board comprises a line in the form of a microstrip conductor. An aperture is provided in the ground plane at a position between the Tee junction and an underlying part of the line conductor. Various Tee junction configurations, such as Y or .DELTA., may be implemented also. The magic Tee may be an integral part of an MIC or MMIC device.

Abstract: A microwave/millimetric receiver of the kind in which a dielectric lens focusses incoming radiation on to an integrated antenna/mixer supported by a dielectric substrate. In one embodiment the antenna/mixer comprises a slot antenna and diode means coupled thereto for mixing the received signal with a local oscillator signal to form an IF signal. The local oscillator signal may be irradiated on to the antenna/mixer to be picked up by a crossed slot antenna or the local oscillator signal may be directly injected into the antenna/mixer circuit say via a microstrip line. In an alternative embodiment, the slot antenna is replaced by a dipole and a local oscillator signal is directly injected into the antenna/mixer via a coplanar line.

Abstract: A unit for detecting a moving person or object by means of doppler frequency shift. The unit comprises a microwave circuit board (1) accommodating an oscillator and a mixer, and an antenna board (2) carrying transmit (8) and receive (9) patch arrays. In the assembled unit the two boards (1,2) are disposed adjacent one another. Coupling between the microwave circuit and the antenna arrays is achieved by two slots (6,11) resonant at the oscillator fundamental frequency and formed in a ground plane (5) on the microwave board (1). Feed striplines (7,10,12) on the two boards (1,2) lie orthogonal to the slots (6,11) and are terminated in T-sections (15,14). The stripline/slot arrangement suppresses emission at the oscillator second harmonic frequency. The antenna board (2) has no electrical connection to the microwave circuit, enabling the radiated beam shape to be changed by simply replacing the antenna board with one having a different patch array pattern.

Abstract: A push-pull modulator stage 70 has two possible transmission paths, an electrically short path (7) and a phase delay path (6) with a phase delay element providing a phase shift of approximately 180.degree.. The phase delay element has the form of a low pass filter. In each of the two paths (6, 7) a semiconductor diode (D.sub.1, D.sub.2) is disposed in such a way that they sense the carrier (U.sub.c) with a phase shift of 180.degree. and, correspondingly, switch in unison if no modulation voltage (U.sub.m) is present, thus suppressing the carrier at the signal output (3). When a modulation signal (U.sub.m) is present, the push-pull balance is disturbed and the resistance of one of the two paths (6) becomes lower relative to the other path (7), which leads to the generation of the modulated carrier voltage (Umc). The modulator stage (70) can also be designed as a dual modulator stage and/or can be used as a mixer stage.

Abstract: Planar millimeter wave transceiver includes a plurality of patch antenna elements disposed on a substrate in right and left hand circular polarization. Microstrip feeds having an intermediate feed point, interconnect adjacent elements. First switches interconnect with the feed points of adjacent feeds and are alternately operable between first and second states for establishing azimuth and elevation. Second switches interconnected with the first switches are alternately operable between first and second states for establishing transmit and receive modes for the antenna and with phase compensation. The microstrip feeds, and the first and second switches are interconnected on the substrate without crossovers. Transmitter and receiver elements may also be incorporated onto the substrate to form an integrated transceiver.

Abstract: A multipole bandpass filter (40) comprises a first microstrip split-ring resonator (12), having at least a first edge and a second edge, the first edge having a gap (20) therein, and an input. The bandpass filter (40) also comprises a second microstrip split-ring resonator (14), having at least a first edge and a second edge, the second edge of the second microstrip split-ring resonator comprising a gap (26) therein and a balanced output (30, 32). The bandpass filter also includes at least one straight line quasi-combline resonator (22), disposed between the first microstrip split-ring resonator, and the second microstrip split-ring resonator.

Abstract: A modulator suitable for 16 quadrature amplitude modulation (QAM) is designed as a double modulator (1), wherein a 16 QAM modulator (39) consists of two double modulators (1). One double modulator (1) has two partial modulators (1',1") forming a bridge. Each partial modulator (1',1") has two possible transmission paths: (6',6") with a phase delay line (39',39") which causes a 180.degree. phase shift. On each of the two paths (6',6", 7',7"), a semiconductor diode (D.sub.1 ',D.sub.1 ",D.sub.2 ',D.sub.2 ") is disposed in such a way that they provide the carrier (U.sub.c) with a 180.degree. phase inversion and are accordingly rendered conductive in unison, if no modulation voltage (U.sub.m) is applied, whereby the carrier is suppressed at the signal output (3'). When a modulation signal (U.sub.m) is applied, the balance is changed to push-pull, and one of the two paths (6',6") assumes less impedance compared to the other path (7',7"), which leads to the generation of the modulated carrier voltage (U.sub.mc).

Abstract: There is disclosed a microwave device having a substrate made of a dielectric material and a frequency conversion circuit formed on a front surface of the substrate and including a microstrip line for input and output and a radio frequency amplifier. The substrate is partially thinned in a portion of a rear surface thereof which faces the radio frequency amplifier. The microstrip line width is a change in the characteristic impedance of microstrip lines which cross the front surface of the substrate where its thickness changes due to the partially thinned portion, is smaller than 10%.

Abstract: A microwave integrated apparatus, particularly useful for a satellite broadcasting receiver, comprises a housing having a radiation aperture and being electromagnetically shielded except for the radiation aperture. An insulated substrate is disposed in the housing, and has formed thereon an antenna pattern capable of receiving or radiating microwaves through the radiation aperture of the housing. A signal-processing means is disposed beside the insulated substrate in the housing, and is connected to the antenna pattern on the insulated substrate. For achieving a microwave circuit arrangement having excellent performance characteristic of a very wide frequency range, a second antenna pattern is disposed at the radiation aperture of the housing, and in proximity to the above-mentioned antenna pattern.

Abstract: A mixer having a diode pair which includes a first RF propagation network having a first end coupled to a first terminal of the mixer and a second end coupled to a first electrode of the diode pair. The mixer further includes a first means, coupled to the first RF propagation network for providing a low impedance DC signal path to ground and for providing a high impedance signal path to signals propagating at a first radio frequency (RF) frequency. A first transmission line resonator is coupled to the first RF propagation network and has an electrical pathlength which is one quarter of a wavelength at a second RF frequency. The mixer further includes a second RF propagation network having a first end coupled to a second terminal of the mixer and a second end of the RF propagation network coupled to a second electrode of the diode pair.

Abstract: A passive uniplanar double-balanced RF mixing apparatus, comprising a planar support substrate with first and second conductive layers disposed on first and second sides, and first and second linear slotlines having open terminations on a first end thereof formed in the first conductive layer. First and second coplanar waveguides are also formed in the first conductive layer with each having one end electrically coupled to first and of said first and second slotlines, respectively. A first balun comprises the first coplanar waveguide connection to the first slotline, and a second balun comprises the second coplanar waveguide connection the second slotline. An isolation gap formed in the first conductive layer adjacent to and between the first and second slotlines provided electrical isolation between the first and second baluns and waveguides for RF-toLO isolation.

Abstract: A compact multi-layer flat antenna structure incorporating a low noise block down-converter on the power divider network layer of the antenna. RF circuit losses are reduced, and the antenna/receiver combination is made more compact, for flush mounting. The antenna/receiver combination finds particular utility in direct broadcast satellite (DBS) applications for single or dual orthogonal polarizations. The connection between the antenna and receiver may be implemented in stripline/coplanar waveguide, or other known technologies such as microstrip, slotline, and finline.

Abstract: A microstripline microwave mixer circuit includes a waveguide microstrip filter formed by coupling a section of ridged waveguide to a microstripline circuit. The ridged waveguide based microstrip filter both serves as a high-pass filter for RF input signals and also provides a suitable termination for the RF input side of the mixer circuit resulting in a compact multifrequency mixer circuit with good performance. The section of ridged waveguide is coupled to the microstripline circuit such that the dielectric substrate of the microstripline circuit is within the waveguide section thereby increasing the effective dielectric constant of the waveguide interior and decreasing the dimensions of the waveguide. This configuration of the high-pass filter presents a smaller component than would be present in air-filled waveguide mixer circuits.

Abstract: A device for tuning a circuit includes a substrate, a transmission line on the substrate that includes first and second conductors coupled to a circuit to be tuned, and a movable short-circuit for varying the impedance the transmission line presents to the circuit to be tuned. The movable short-circuit includes a dielectric layer disposed atop the transmission line and a distributed shorting element in the form of a conductive member that is configured to be slid along at least a portion of the transmission line atop the dielectric layer. The conductive member is configured to span the first and second conductors of the transmission line and to define at least a first opening that spans the two conductors so that the conductive member includes first and second sections separated by the first opening.

Abstract: A millimeter wave device having a dielectric substrate with a pair of substantially parallel planar surfaces with at least one predetermined millimeter wave circuit pattern formed in a conductive layer located on at least one of the substrate surfaces. A substantially planar conductive channel plate is mounted adjacent the conductive layer on one substrate surface with the channel plate having an aperture overlying each circuit pattern formed in the conductive layer. A substantially planar conductive cover plate is mounted adjacent one of the channel plates so as to form a first cavity in the region defined by the substrate surface, the channel plate aperture and the cover plate. The device may further include a second substantially planar conductive channel plate mounted adjacent the other one of the substrate surfaces with the second channel plate having an aperture corresponding to and aligned with the first channel plate aperture.

Abstract: An image suppression harmonic frequency converter capable of operating in any microwave range is described. Frequency conversion is obtained by making use of a local frequency which is half that of a conventional converter. In particular, the radiofrequency reception signal is converted into an intermediate frequency signal with suppression of the converted image band. Similarly, the intermediate frequency signal to be transmitted is converted into a single side band radiofrequency transmission signal. The converter comprises two harmonic mixers, a first inquadrature radiofrequency hybrid coupler, a second in-quadrature intermediate frequency hybrid coupler, two appropriate duplexer filters, two low-pass filters, two matching circuits, and two decoupling circuits.

Abstract: Circuits such as balanced diode mixers require balanced transformers. For ultrahigh frequency operation, a balanced transformer is formed as part of a printed circuit on a planar substrate of insulating material. The balanced transformer has a center-tapped winding formed by a loop of a strip transmission line having first and second coextensive elongated conductors disposed on the substrate. Preferably the first and second conductors are disposed adjacent each other on respective opposite sides of the substrate. At a first end portion of the strip transmission line, the second conductor is connected to a center tap, and at a second end portion of the strip transmission line, the first conductor is also connected to the center tap. For a balun transformer, the center tap is a ground plane provided by conductive regions disposed on the substrate.

Abstract: The present invention relates to a frequency converter circuit which can be used in a receiving apparatus for receiving a satellite broadcast and which is designed so that a local oscillation signal is distributed and supplied from a single local oscillator to mixer circuits of electric signal processing circuits of more than two systems and mixer diodes of the mixer circuits are biased with a dc current thereby always applying a biasing with the dc current even to the mixer diode of the electric signal processing circuit of the system which is not operated, and there are advantages of ensuring a stable operation, making possible a reduction in the size and weight and making favorable from the cost point of view.

Abstract: In a millimeter wave monopulse first detector array for use in seeker applications in a guided missile employing quasi-optical, or Gaussian beam, signal transmission, a first detector is shown to include a patch antenna array, a mixer and a power divider in a monolithic implementation for extraction of the monopulse information in a radar receiver.

Abstract: A subharmonic mixer is shown to comprise two pairs of matched antiparallel GaAs diodes disposed on a dielectric slab and operative with microstrip circuitry. By suppressing the fundamental mixing products, mixing the radio frequency signal with the second harmonic of a local oscillator (LO) signal and using relative phase differences of the LO signals in the two pairs of diodes, undesirable effects from spurious signals are minimized.

Abstract: A balun section formed of a pair of transmission lines connected between separate pairs of corresponding input and output terminals with a pair of capacitors connected in series between the output terminals and another transmission line connected in series with a resistor between the circuit ground and the interconnection between the pair of capacitors. A multisection balun is constructed from a plurality of such balun sections connected in cascade. In one embodiment, the outputs of a pair of multisection baluns are supplied to a circuit such as a mixer or the like.

Abstract: A simple balanced-mixer circuit that uses the resistive channel of a GaAs MESFET exhibits superior intermodulation performance, with other performance parameters, e.g., conversion loss, port impedances, and LO sensitivity, being equal to or better than other diode mixers.

Abstract: Receiver configuration for microwave signals with a receiver antenna, a rectifier circuit and a detector circuit, wherein only one single antenna is provided to receive a vertically polarized energy signal and a horizontally polarized data signal. It has separate detector circuits available for the energy signal and the data signal. The detector circuit for the energy signal consists of a voltage doubling circuit to generate an operating voltage and the detector circuit for the data signal consists of a diode with a shunt resistor to generate a modulated DC voltage.

Abstract: A monolithic millimeter wave mixer. The mixer utilizes a resonant disk and wo microstrip arms with in-situ Schottky diodes. A microstrip low pass filter which is gap-coupled to the disk permits isolation of the desired intermediate frequency.

Abstract: A microwave mixer suitable for millimeter wave radar applications. A semi-insulating gallium arsenide dielectric waveguide structure contains an embedded planar doped barrier (PDB) structure as a non-linear mixing element. The local oscillator (LO) signal is guided to the PDB structure via a coplanar type waveguide. The radio frequency (RF) signal is guided to the PDB structure via an image guide and a microstrip circuit serves to transmit the intermediate frequency (IF).

Abstract: A combined duplexer/mixer especially for use in an FMCW millimetric radar system has a waveguide section containing a fin line or suspended strip structure for responding to the linearly polarized radar return signal passing through the section in one direction while permitting passage of the orthogonally polarized, outgoing signal passing in the other direction. The fin line is coupled via double balanced mixer diodes to an IF output line to produce an IF signal by mixing the return signal with a portion of the outgoing signal tapped off by a field distorting probe, ridge section or like coupling means.

Abstract: A microwave balun using microstrip broadside coupled lines is disclosed for achieving a broadband double balanced mixer or modulator performance. The use of a double layered structure for broadside coupled microstrip lines, called overlapped microstrip lines, makes a balun design equivalent to well known double coaxial Marchand design. It is feasible by means of thin film and MMICs technology. The most advantageous applications of the balun include its simple and inverted options useful for mixer or modulator design considering both the balun and semiconductor junctions manufactured in one compact volume of the lower substrate. A balun circuit layout is one-sided fixed to a contiguous ground plane without using slots or holes in it and othersided open from a top side. The application is dedicated to an approximate frequency range of at least 1 to 18 GHz.

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: The invention provides a coupling device between a metal wave guide (three dimensional system) and an electronic signal processing circuit (two dimensional system). The transition is provided by means of a dielectric wave guide introduced longitudinally into the metal wave guide. A chamfer cut in the dielectric guide concentrates the energy of the input signal on a face of the dielectric bar, at the interface with another dielectric material (isolated image guide). At this interface, a microstrip line transmits the energy to a semiconductor component.

Abstract: A coplanar microwave balun is disclosed in which a signal propagating along a coplanar waveguide in an unbalanced mode is launched onto another coplanar transmission line in the balanced mode. One of the ground planes of the latter transmission line itself is separated into a pair of regions which constitute the ground planes of the coplanar waveguide. These pair of regions are electrically connected, e.g., by ribbon bonds that bridge across the transmission line strip of the coplanar waveguide. The end of that transmission line strip bridges across the coplanar transmission line and acts to launch the signal thereto. The inventive balun advantageously is employed in a three port device having isolated inputs from which separate signals may be multiplexed onto a common line, and may be used in other multiplexer, mixer and modulator assemblies.

Abstract: A frequency converter which is capable of rejecting unnecessary signals generated by image signals. The frequency converter has first and second local oscillation circuits which generate local oscillation signals whose frequencies are the same and whose phases are different by 90 degrees from each other. The converter further includes two mixer circuits, and a hybrid coupler. The mixer circuits generate two unnecessary signals whose phases are different by 90 degrees from each other. The hybrid coupler delays one unnecessary signal by a quarter of a wavelength to generate two unnecessary signals whose phases are different by 180 degrees from each other, so that they are cancelled by each other.

Abstract: A TVRO receiver utilizes an improved voltage-controlled oscillator (VCO) of the surface mounted type which has a wide bandwidth of operation extending into the microwave frequency range. The VCO comprises a dielectric substrate with a patterned-metal layer on one side and a surface mounted oscillator on the patterned-metal side of the substrate. The oscillator comprises amplifying means which produce an oscillating output by the use of regenerative feedback means including an open-circuit-stub inductance formed in the patterned metal layer, and a tunable resonant circuit coupled to the amplifying means in order to control the frequency of the oscillating output. The resonant circuit includes a short-circuit-stub capacitance formed within the patterned middle layer, at least one variable capacitance diode in series with the short-circuit stub, and means for applying a controllable tuning potential to the resonant circuit.

Abstract: A signal converter comprises a filter formed of a first ferromagnetic resonator which supplied with an input signal that is to be converted and produces a filtered signal having a first frequency, a local oscillator formed of an active element and a second ferromagnetic resonator connected to the active element, produces an oscillating signal having a second frequency, a mixer receives and mixes the filtered signal and oscillating signal and produces a converted signal, the first ferromagnetic resonator is formed of a first ferrimagnetic crystal, a microstrip line magnetically coupled to the ferrimagnetic crystal and a first D.C. bias magnetic field means which applies a first D.C. bias magnetic field to the first ferrimagnetic crystal, the second ferromagnetic resonator is formed of a second ferrimagnetic crystal, a second microstrip line is magnetically coupled to the second ferrimagnetic crystal, and a second D.C. bias magnetic field means which applies a second D.C.

Abstract: A frequency converter for use in a 4 GHz-band comprising a printed circuit board and a shield case. The printed circuit board is provided in the shield case and composed of an input terminal, and successively, a circuit of low noise amplifier, a band pass filter, a mixer and a circuit of local oscillator connected to the mixer. The constitution of the frequency converter is simplified, and accordingly the mass productivity, yield of production and reliability of the fabricated converter are greatly improved.

Abstract: Insertion and conversion losses in a dual frequency microwave mixer circuit are lessened with the improved configuration disclosed herein. The circuit provides inputs for two local oscillator signals, each coupled through a respective bandpass filter. In another embodiment, a pair of notch filters provided near the input reduce leakage from the oscillator inputs to the signal input.

Abstract: In a waveguide-to-microstrip line coupling arrangement, a microstrip line is placed on an outer surface of a wall of a waveguide which is coupled with the microstrip line via a metallic post connected at its one end to a center strip conductor of the microstrip line and is inserted inside the waveguide via through-holes made in a ground plane of the microstrip line and in the wall of the waveguide where the diameter of the through-hole made in the ground plane is made smaller than that of the through-hole made in the wall of the waveguide. The waveguide has a short-circuited end and the metallic post is placed close to the short-circuited end. The coupling arrangement may be used in a microwave frequency converter having an microwave integrated circuit including a local oscillator and a mixer, where the MIC is located on an outer surface of a longitudinal wall extending from a short-circuited end to an open end.

Abstract: A novel mixer of good noise performance for operation at microwave frequencies (e.g. the 22 GHz communications band) is disclosed. The mixer comprises a waveguide to which signals and local oscillations are coupled, and from which the intermediate frequency output is derived. The principal circuitry is provided on a metallized substrate set within the waveguide in a "finline" construction. The metallized substrate performs the essential functions of impedance matching the mixer to the source of signal and local oscillations, a bridge for isolating the signal port from local oscillations and for isolating the LO port from the signal, and means to adjust the application of signal and load to the mixer diodes for optimum signal conversion. The noise figure achieved is approximately 4 db at 22 GHz, and represents an improvement over known competitive designs.

Abstract: A wideband enhancement sum mixer is shown to comprise a pair of matched GaAs diodes operative with a printed circuit wherein a portion of at least the sum signal, i.e., the sum of a radio frequency signal and a local oscillator signal, is caused to be mixed with the second harmonic of the local oscillator signal to produce an intermediate frequency signal in phase with the intermediate frequency signal resulting from mixing of the radio frequency signal and the local oscillator signal.

Abstract: A microwave integrated circuit comprises a shield case having a pair of opposed first and second end walls, a pair of side walls and top and bottom walls, and a dielectric substrate on the bottom wall. First and second interconnected integrated circuit portions are arranged on the substrate between the first and second end walls. An input strip line is arranged on the substrate, the strip line having one end coupled to the input of the first integrated circuit portion and the other end terminating at a position spaced from the first end wall by a distance approximately equal to an integral multiple of the half wavelength of a signal propagating in the shield case. An elongated coupling member is disposed in parallel with the first end wall, the coupling member extending from the other end of the input strip line to an external circuit.

Abstract: A planar monolithic self-oscillating mixer for millimeter wave applications s formed on a gallium arsenide substrate. A via hole extends from the bottom surface to the top surface of the substrate. Metal is plated on the bottom surface of the substrate and in the via hole forming a heat sink. Above the heat sink are disposed three gallium arsenide layers--an N layer between two N.sup.+ layers. The top layer has a metal connection formed thereon. The gallium aresenide layers are epitaxially deposited using vapor phase techniques. Unwanted portions of these layers are mesa etched away. A radio frequency microstrip transmission line is disposed on the upper surface of the substrate. This transmission line is gap coupled to the Gunn diode and extends to one edge of the substrate. An intermediate frequency microstrip transmission line is connected to the metal connection on the top N.sup.+ layer.

Abstract: A monolithic millimeter wave balanced mixer in which two Schottky barrier odes receive combined power from. Two Schottky barrier diodes receive combined power from an RF source and local oscillator in a gallium arsenide image guide. The diodes produce an intermediate frequency which is directed to a microstrip low pass filter.