Abstract: In a resonator in which a ground plane and a patch sandwich a dielectric, a slot in the patch concentrates emanation of radiation from the slot. Shorting conductors form the ends of the resonator. A dielectric cover over the slot matches the dielectric constant of the substrate to that of free space. Quarter-wave chokes at the ends of the resonator suppress currents in the ground plane.

Abstract: The effectiveness of a microstrip conductor antenna, such as a patch antenna, is improved at any particular frequency by making the thickness of the conductor sufficiently small to reduce shielding and losses caused by the skin effect and make currents at the upper and lower surfaces couple with each other and make the conductor partially transparent to radiation. In one embodiment the thickness is between 0.5.delta. and 4.delta.. Preferably the thickness is between 1.delta. and 2.delta. where .delta. is equal to the distance at which current is reduced by 1/e., for example 1.5 to 3 micrometers at 2.5 gigahertz in copper. According to an embodiment, alternate layers of dielectrics and radiation transparent patches on a substrate enhance antenna operation.

Abstract: An RF apparatus (e.g., a wireless label) provides improved backscattering of an incident RF signal by utilizing a separate modulator diode, which connects across the antenna, to modulate the backscattering of the antenna. A separate detector diode connects across the antenna through an impedance matching network to detect modulated signals received by the antenna.

Abstract: Dielectric components extend between top and bottom surfaces of a ground plane in a resonant microstrip patch antenna over a distance of one-quarter-wavelength of a resonant frequency of the antenna. The components form quarter-wave chokes within which waves cancel with reflected waves and reduce currents in the bottom surfaces of the ground plane. This reduces back lobe responses.

Abstract: A diode detector is integrated into a microstrip patch antenna. Tuning and matching of the detector are accomplished by adjusting the geometry of the patch. Cost, power consumption, losses, and spurious responses are reduced. The antenna may be adapted to a mixer, video detector, i.f. detector, or audio detector.

Abstract: The present invention relates to a high-power solid state amplifier arrangement comprising a large number of solid state amplifiers disposed in a waveguide array. The waveguide array is disposed in the aperture of an antenna feed arrangement at the image plane of an antenna feed to receive a uniform distribution over the array with substantially no spillover. Each of the large number of parallel waveguide sections of the array includes one or more solid state amplifiers in a serial, waveguide-interconnected, arrangement, and a wideband impedance matching arrangement in the waveguide configuration at the input and output of the section.

Abstract: The present invention relates to a QPSK modulator or demodulator for modulating two different input bit streams with a subharmonic pump carrier signal to produce an appropriately encoded QPSK output signal. The subharmonic pump carrier signal used is a submultiple of a predetermined microwave or millimeter-wave carrier frequency. The QPSK modulator or demodulator is capable of being fabricated on a planar substrate using appropriate stripline filters and a mixer diode in each of an in-phase and quadrature signal path. A fin line arrangement, also capable of fabrication on the substrate, can be used to introduce an appropriately phased subharmonic pump carrier signal into each of the in-phase and quadrature signal paths before each mixer diode.

Abstract: A metal gate field effect transistor has its source and drain located on one major surface of a gallium arsenide layer, while its gate electrode forms a Schottky barrier contact to an opposed major surface of the layer in a self-aligned relationship to the source and drain.

Abstract: A stripline features high symmetry and promotes uniform current densities to lower losses. The channel (11) of the outer conductor of the stripline has a generally circular cross-section. Opposing lateral grooves (13,14) securely positions a substrate (16) which includes a center conductor. The center conductor features dual metalized strips (17,18) connected together by spaced through-plated holes (19). The stripline is readily formed in a single block of metal and hence eliminates the losses associated with the joint of conventional split-block striplines.

Abstract: The present invention relates to a technique for displacing spurious resonances which are excited in strip transmission line circuits outside the frequency band of interest. Such displacement is accomplished by adding apertures in the capacitive elements of the strip transmission line circuit which have dimensions to move the transverse resonances out of frequency band of interest while causing, for example, no significant change in the passband ripple or the stopband attenuation of a filter. The slots effectively cause the inductance across the capacitive element to increase and, therefore, lower the frequency of the transverse modes or resonances.

Abstract: The present invention relates to millimeter waveguide shorts and methods for making said shorts wherein an exemplary rectangular cross-sectioned waveguide short comprises a base substrate such as steel shimstock or foil having a width equal to the associated millimeter waveguide, a raised portion disposed laterally on both sides of the substrate at alternate quarter-wavelength sections adjacent one end of the substrate. The raised portions comprise a first layer of good electrically conductive material disposed on the substrate and a second layer of an insulating material formed atop the first layer. Alternatively, the exposed substrate sections can be gold plated. A preferred method comprises the steps of masking alternate quarter-wavelength sections of the exposed major surfaces adjacent one end of the substrate, depositing the first layer material on the unmasked quarter-wavelength sections and depositing the second layer material on the exposed major surfaces of the first layer material.

Abstract: A Schottky barrier semiconductor device and process for making same is described wherein edge breakdown is avoided by making the rectifying contact in a curved depression in an epitaxial active layer having a nonuniform doping profile. The depression is formed by anodizing a portion of the epitaxial layer and etching the anodic oxide. Etching and electroplating of the contact are done in the same solution to avoid contamination of the metal-semiconductor interface.