Abstract: An integrated circuit amplifier comprises: a first planar substrate having an upper surface and a lower surface; a second planar substrate having an upper surface and a lower surface, the lower surface of the second planar substrate physically affixed to the upper surface of the first planar substrate; at least one transistor pair comprising a first and second transistor, formed in the upper surface of the second planar substrate; and a conductor electrically coupling a drain electrode of the first transistor to a source electrode of the second transistor. The first substrate material may have a higher thermal conductivity than the second substrate material. The first material may be Silicon Carbide and may have a thickness of about 10 mils. The second material may be Gallium Arsenide and may have a thickness of about 1 to 2 mils.

Abstract: A radio frequency (RF) power limiter including a signal conductor having an input end and an output end and first and second limiter stages. The first limiter stage comprises a plurality of stacked diode strings arranged in anti-parallel with respect to the signal conductor. The second limiter stage comprises a second plurality of stacked diode strings arranged in anti-parallel with respect to the signal conductor. An all pass filter is arranged between the first and second limiter stages.

Abstract: An integrated circuit comprises a GaAs substrate thermally and mechanically mounted on a SiC substrate. The GaAs substrate is doped to define first and second transistors. Circuit conductors are defined on the GaAs substrate, which conductors interconnect the source of the first transistor to neutral and the drain to the source of the second transistor. Conductors connect the gate of the second transistor to neutral, to define a cascode amplifier. The SiC substrate supports first and second matching circuits, one of which is connected to the gate of the first transistor, and the other of which is connected to the drain of the second transistor.

Abstract: A power divider/combiner is formed from multimode dielectric waveguides in hich energy in a single mode is translated into a plurality of modes in the multimode waveguide, each mode is separately amplified and applied to another multimode waveguide that combines the modes in phase at the output thereof.

Abstract: A planar antenna for microwave applications includes a supporting structure that is made using standard LTCC (low temperature co-fired ceramics) multi-layer techniques and a polyimide tape containing an adhesive at one side which is adheringly attached to the supporting structure. The body of the supporting structure defines a transmission line substrate and several of the intermediate layers define a path for microwave energy to be coupled from the transmission line substrate to the antenna. The method includes adhering the tape to the supporting structure, cutting the tape to size, and baking the tape and supporting structure in an oven at about 180.degree. C. for about 4 hours to rigidify the tape. The obtained antenna is thus protected against substrate effects such as TM mode zero cut-off frequencies.

Abstract: A composite structure including stacked layers of dielectric material hav a center conductor in the form of a cylindrical via which is surrounded by an annular dielectric region and an outer ground plane comprised of contiguous pairs of generally circular ground plane segments where each pair of ground plane segments are separated by a pair of spaces or gaps therebetween and wherein the gaps of adjoining layers are mutually oriented by a predetermined angle of rotation, preferably 90.degree..

Abstract: The invention is directed to resonators and more particularly to an MMIC-compatible resonator which can be fabricated on an MMIC chip using MMIC processing techniques. The MMIC-compatible resonator has a substrate approximately 100 microns thick made of semi-insulating GaAs and/or AlGaAs. The substrate flanks an air via on which is fabricated a thin film piezoelectric semi-insulating GaAs film, comprising the piezoelectrically active element. The piezoelectrically active element is flanked either laterally or from the top to bottom thereof by a pair of electrodes which serve to excite the thickness shear or thickness extensional mode of the thin film piezoelectrically active element. There are a number of III-V and II-VI binary compounds and ternary, and other piezoelectric semiconductor alloys, which can be used for the purposes of the invention. The thin film measures approximately 5 microns or less in thickness and is fabricated on the semi-insulating GaAs, on the ?110!, ?111! or ?100! axis thereof.

Abstract: A composite structure including stacked layers of dielectric material hav a center conductor in the form of a cylindrical via which is surrounded by an annular dielectric region and an outer ground plane comprised of contiguous pairs of generally circular ground plane segments where each pair of ground plane segments are separated by a pair of spaces or gaps therebetween and wherein the gaps of adjoining layers are mutually oriented by a predetermined angle of rotation, preferably 90.degree..

Abstract: An optically controlled MESFET semiconductor oscillator assembly having a MESFET semiconductor which, when voltage biased by a pulsed dc voltage, oscillates at a free running frequency; an optical signal delivery system, such as a light intensity modulator connected to optical fibers; and other oscillator circuitry including a pulse generator. In operation, the pulsed free running oscillation of the MESFET semiconductor can be injection locked to the intensity modulated optical signal delivered via the optical signal delivery system.

Abstract: A dual-gate self-oscillating mixer FET that is injection-locked from a remote LO frequency source. The dual-gate FET having a feedback circuit connected between the first gate port and the drain port that is tuned so that the FET can oscillate within a frequency range including a predetermined LO frequency. The FET having a remote synchronization circuit electrically connected to the FET first gate port to inject the predetermined LO frequency therein and lock the FET oscillation to that LO. Accordingly, the dual-gate FET mixes RF energy input to the second gate port with the locked LO injected in the first gate port and outputs the desired intermediate frequency through the drain port.

Abstract: The dielectric resonator assembly includes a housing having interior surfaces defining a resonant cavity and a dielectric resonator within the cavity. The dielectric resonator is a ceramic having a high dielectric constant and generates pulses at a desired frequency of oscillation. A pedestal supports the dielectric resonator within the resonant cavity so that it spaces the resonator apart from each of the interior surfaces of the cavity. The assembly also includes a transmission line for transmitting the pulses which pass through at least one of the interior surfaces and has an interior portion spaced apart from the remaining interior surfaces of the cavity. The interior portion of the transmission line is positioned proximate to and in magnetically coupled relationship with the dielectric resonator.

Abstract: A tapered waveguide for transmitting optical signals from a signal source to an optical fiber is fabricated by irradiating a layer of prepolymer resin on a substrate with a converging beam of ultraviolet light, whereby the irradiated resin polymerizes into a clear, hard polymer and the resin that has not been irradiated remains in its resinous state. The unpolymerized resin is removed with an organic solvent. The variation in width of the waveguide is achieved by varying the distance between the source of the converging beam of ultraviolet light, thereby varying the diameter of the spot that is being irradiated, while simultaneously moving the source of ultraviolet light parallel to the axis of the waveguide. Variation in thickness of the waveguide is achieved by sloping the substrate.

Abstract: The coupling of optical signals to the active region of a FET having a wide source to drain spacing via an optical fiber and material having an index of refraction matching that of the fiber or the FET so as to increase the locking range when the FET is part of an oscillator circuit or to increase the change in the electrical gain of the FET caused by a change in the optical energy if the FET is an amplifier.

Abstract: An optically controlled oscillator circuit having an oscillator field eff transistor (FET) and having a separate light sensing quench FET. The optically controlled oscillator circuit includes, a light source, a control connected to the light source, an optic fiber having an end coupled to the light source, a quench field effect transistor (FET) coupled to a second end of the optic fiber, an oscillator FET, each FET being a GaAs multi-finger FET having drains and sources and gates, and a circuit connected in series circuit through the drains and sources of the quench FET and oscillator FET across a source of positive voltage.

Abstract: A fundamental or subharmonic optically injection locked oscillator is coupled to a phase locked loop circuit. The injection locked oscillator has two single stage HEMT amplifiers with parallel feedback from the drain of a second transistor to a gate of a first transistor. A feedback resonant network controls the oscillator frequency. A microwave/millimeter wave source modulates a laser diode and the signal from the laser diode is then transmitted via an optical fiber to a PIN photodetector diode. The signal from the photodetector diode is injected into the oscillator at an nth subharmonic of the oscillator frequency. The feedback network may consist of a microstrip gap resonator with two tuning varactors at the ends of the resonator. The phase locked loop includes a balanced mixer used as a phase detector to compare the nth harmonic of the signal from the photodetector diode to the sampled output of the oscillator.

Abstract: An optically controlled resonant tunnel diode oscillator assembly having a esonant tunnel diode (RTD) which, when voltage biased, oscillates at a free running frequency; an optical signal delivery system, such as a light intensity modulator connected to optical fibers; and other oscillator circuitry which one skilled in the art could readily adapt to the concepts of the present invention. In operation, the free running oscillation of the RTD can be frequency modulated or can be intensity locked to the intensity modulated optical signal delivered via the optical signal delivery system.

Abstract: An optical controlled attenuator circuit for controlling a microwave varie attenuator. The optical controlled attenuator circuit includes, a light source, a control connected to the light source, an optic fiber having an end coupled to the light source, a field effect transistor coupled to a second end of the optic fiber, a first inverting amplifier coupled to the field effect transistor, a second non-inverting amplifier coupled to the first amplifier means, a third non-inverting amplifier coupled to the second amplifier, a fourth inverting amplifier means also coupled to the second amplifier, and a microwave variable attenuator having first and second inputs respectively coupled to the fourth inverting amplifier and to the third non-inverting amplifier means and having an RF input and an RF output.

Abstract: An optically injection locked resonant tunnel diode oscillator assembly hng a resonant tunnel diode (RTD) which, when voltage biased, oscillates at a free running frequency; an optical signal delivery system, such as a light intensity modulator connected to optical fibers; and other oscillator circuitry which one skilled in the art could readily adapt to the concepts of the present invention. In operation, the free running oscillation of the RTD can be locked to the phase and frequency of the intensity modulated optical signal delivered via the optical signal delivery system. This injection locking occurs as the modulation frequency approaches the free running oscillation frequency.

Abstract: An optical controlled switch circuit for controlling a two-way voltage drn microwave switch. The optical controlled switch circuit includes, a light source, a control connected to the light source, an optic fiber having an end coupled to the light source, a field effect transistor coupled to a second end of the optic fiber, an inverting dc amplifier means coupled to the field effect transistor, a non-inverting dc amplifier means coupled to the field effect transistor, and a two-way voltage driven microwave switch having signal inputs respectively coupled to the inverting dc amplifier means and to the non-inverting dc amplifier means and having a microwave input and having first and second microwave outputs.