Abstract: A frequency selective limiting device is described incorporating a plurality of individual attenuating units spaced apart from one another in substantially parallel relation and positioned between a pair of ground planes. Each individual attenuating unit is interposed between a pair of magnetic strips. In one embodiment of the invention, each individual attenuating unit includes a microstrip conductor positioned between a dielectric substrate layer and a layer of ferrite material. In an alternate embodiment of the invention, each individual attenuating unit includes a microstrip conductor positioned between a pair of planar ferrite members, the pair of ferrite members and microstrip conductor being mechanically supported by a dielectrical substrate layer. In both embodiments of the invention, adjacent attenuating units are serially connected by microstrip jumpers to provide a flow path for microwave signals passed through the limiting device.

Abstract: A microstrip microwave circuit having embedded therein at least one suspended substrate stripline region for high Q circuit elements is disclosed. Each suspended substrate region includes an upper ground plane formed by covering the microstrip circuitry of each region with a metallic housing having holes in the sidewalls thereof to permit passage therethrough for the interconnecting circuit paths of the region and by connecting the housing to the top surface of the microstrip ground plane substrate; and a lower ground plane formed by removing the section of substrate lying substantially underneath each high Q region to form openings in the bottom surface of the substrate which are covered by an individual cover plate. The upper and lower ground planes are separated from their corresponding high Q regions by an air spacing dimensioned as a function of the RF impedance desired.

Abstract: A radar receiver protector having high isolation and low insertion losses due to a unique microwave assembly configuration is disclosed. The receiver protector includes at least one high power input protection stage and a sensitivity time controlled multi-level attenuation which together achieve rapid switching with a non-critical bias supply and circuit configuration and develop attenuation levels which are invariant with temperature and insensitive to diode parameters.

Abstract: A unidirectional phase shifter provides selectable phase changes for linearly polarized microwaves of electromagnetic radiation entering the phase shifter in one direction and constant insertion phase for linearly polarized microwaves entering the phase shifter in the opposite direction. The phase shifter consists of two ferrite phasor sections arranged such that the phase changes of the two sections add for one direction of signal flow and cancel for the other. Each phasor section includes a ferrite half-wave plate, at one end of which is coupled a ferrite quarter-wave plate, and at the other end of which is coupled a dielectric quarter-wave plate. The dielectric quarter-wave plate of one of the phasor sections is coupled to the ferrite quarter-wave plate of the other phasor section.

Abstract: A parametric amplifier having a beam lead dual Schottky barrier diode fabricated on a single semiconductor chip across a waveguide cavity. Two anode leads are bonded to the adjacent waveguide walls for coupling to a pump source; and a common cathode lead is bonded to a signal circuit. Parasitic reactances are reduced by minimizing stray capacitance and beam lead series inductance.

Abstract: A circuit for selectively variably setting the magnetic remanence in a magnetizable core employs flux circuit feedback, including feedback initiating a self-blocking oscillator type of operation, to achieve designs of two or three (as the designer may desire) elementary sequences (referred to in the art as cycles) to erase previous remanent flux density and to set a new remanent flux density. The circuit apparatus is amenable to constructions using single monolithic integrated circuit chip techniques.

Abstract: A miniature waveguide attenuator which may be used in a dominant-mode (TEb.10) waveguide to maintain a low VSWR over a 20% frequency band comprising a short section of waveguide with an E- or an H-plane tee whose width is selected to set the cutoff frequency of the branch line of the tee at the design frequency F.sub.o. The branch line of the tee is terminated in a lossy material followed by a short circuit for absorbing energy propagating down the waveguide at frequencies higher than the design frequency in accordance with a controlled attenuation characteristic.