Abstract: The present invention relates to a novel use of cryoelectronic equipment to implement an extremely sensitive and stable receiver front end for UHF, microwave, and millimeter wave applications. The invention is particularly applicable to base station receivers in mobile radio systems, where the range and capacity of the systems are typically limited by the base station receiver sensitivity.

Abstract: The present invention is directed to a method for forming dielectric thin films having substantially reduced electrical losses at microwave and millimeter wave frequencies relative to conventional dielectric thin films. The reduction in losses is realized by dramatically increasing the grain sizes of the dielectric films, thereby minimizing intergranular scattering of the microwave signal due to grain boundaries and point defects. The increase in grain size is realized by heating the film to a temperature at which the grains experience regrowth. The grain size of the films can be further increased by first depositing the films with an excess of one of the compoents, such that a highly mobile grain boundary phase is formed.

Abstract: The tunable filters of the present invention incorporate tunable dielectric materials (e.g., bulk and thin film ferroelectric and paraelectric materials) in contact with segments of resonators that are at an RF voltage maximum to alter the pass band or stop band characteristic of an RF signal outputted by the filter. The biasing circuitry in contact with the tunable dielectric material can include components for inhibiting or retarding the coupling of RF energy to the biasing circuit.

Abstract: The present invention relates to a tuneable fringe effect capacitor for conducting radio frequency energy. The capacitor includes a thin film of ferroelectric material, a pair of films of a conductive material deposited on the ferroelectric film with a gap between the films, and a substrate for the ferroelectric material and the conductive films. The capacitance value across the gap is varied by applying a voltage to the ferroelectric material and thereby altering the dielectric constant of the ferroelectric material.

Abstract: The disclosure relates to a phased array antenna for microwave and millimeter wave applications, using either microstrip line, coplanar waveguide, or other construction techniques incorporating a solid dielectric transmission line. A continuously variable phase delay structure which is used to control the beam pattern of the phased array antenna can be applied to the construction of resonant frequency tunable coplanar waveguide antennas and impedance tunable quarter-wave transformers. A thin film of barium strontium titanate (Ba.sub.x Sr.sub.1-x TiO.sub.3) or other nonlinear material such as PbZr.sub.x Ti.sub.1-x O.sub.3 (PZT), LiNbO.sub.3, etc. is deposited upon the coplanar waveguide, and/or the patch antenna element. The dielectric constant of the thin film can be made to vary significantly by applying a DC voltage to the thin film. The propagation constant of a transmission line is directly proportional to the square root of the effective dielectric constant (assuming a lossless dielectric).

Abstract: The present invention provides a superconducting device having a weak link junction with an angle at the grain boundary between the two superconductor crystals being variable. The angle at the junction is substantially equivalent to a vicinal angle for the substrate. Accordingly, the magnitude of the angle at the junction can be varied by varying the vicinal angle of the substrate. This result can be realized by using buffer layers of different compositions underlying the superconducting materials on either side of the weak link junction. Weak link junctions and reproducible properties are essential for a variety of electronic and magnetic sensing devices.

Abstract: The disclosure relates to ferroelectric and superconducting thin films used in combination to produce low-loss passive microwave and millimeter wave devices which are frequency tuneable. Various metal oxide superconducting and ferroelectric thin films can be deposited in numerous multilayer geometries via a variety of deposition techniques to produce devices which can manipulate microwave and millimeter wave signals through the application of voltage bias signals across the ferroelectric films. Numerous superconducting microwave and millimeter wave devices, including delay lines, phase shifters, resonators, oscillators, filters, electrically-small antennas, half-loop antennas, directional couplers, patch antennas, and various radiative gratings, are made frequency-tuneable by utilizing voltage-tuneable capacitor structures fabricated from voltage-biased ferroelectric thin films.