Abstract: The present invention provides a switched-line phase shifter (300) for creating a differential phase shift between switched transmission paths (302, 304). A switched-line phase shifter (300) incorporates Schiffman sections (306, 308) of lengths which are non-integer multiples of quarter-wavelength. The lengths of the Schiffman sections (306, 308) are chosen such that no isolation points, which result from frequencies at which the effective electrical length of one of the transmission paths (302, 304) is an integer multiple of &lgr;/2, occur over the operating frequency range of the phase shifter (300). The present invention also provides a space-efficient implementation of a switched-line phase shifter (600) which utilizes switches (640, 642, 644) between Schiffman subsections (610, 630) to alternately combine and isolate the Schiffman subsections (610, 630) thereby alternately creating effective Schiffman sections of greater and lesser length respectively.

Abstract: A quenchable VCO that is adapted to be used in switched band synthesizer applications. The VCO may be formed from a heterojunction bipolar transistor (HBT) in a common collector configuration. A quenching circuit which includes a p-i-n diode, is electrically coupled in series with the collector of the HBT. The p-i-n diode is adapted to be monolithically integrated with the HBT. Since the p-i-n diode is electrically connected to the collector of the HBT, as opposed to the base and emitter terminals of the HBT, which forms the main oscillator feedback loop, the Q-factor of the p-i-n diode will have relatively less loading on the phase noise of the HBT oscillator. Moreover, since the p-i-n diode is isolated from the base-emitter junction, the configuration will result in reduced frequency pulling and generation of spurious oscillation and transient effects due to the switching of the p-i-n diode quenched circuit.

Abstract: An antenna includes a truncated waveguide capable of supporting propagation of electromagnetic energy having an electric field component. A dielectric plate is located partially within and partially without the waveguide of the truncation, and is oriented parallel to the E field and the longitudinal axis of the waveguide. An upper half of one side of the dielectric plate bears a conductor pattern defining half of a finline. The lower half of the other side of the dielectric plate bears a second conductor pattern defining the other half of a finline. In the region without the waveguide, the finline diverges to form a radiating portion with high gain. In another embodiment, a finline is formed on both sides of the dielectric plate.

Abstract: A patch antenna, which may be one element of an antenna array, is formed on one broad surface of a semiconductor plate. A ground plane is formed on the second broad surface. This semiconductor is doped in regions near a periphery of the patch to define a semiconductor PN junction have electrode contacts to the patch and to the ground plane. The junction has capacitance which tunes the patch antenna. The characteristics of the junction are controlled by bias to selectively tune the patch antenna. The bias is a direct voltage in one embodiment of the invention. In another embodiment, the junction work function itself provides a bias which is controlled by temperature control of the diode.

Abstract: Antennas chiefly intended for microwave and millimeter-wave use include geometric-shaped conductive patches on one broad surface of a planar semiconductor substrate. The other broad side of the substrate bears a conductive ground plane. Monolithic PIN diodes are formed by doping the substrate at various points between the conductive patch and the ground plane. Biasing arrangements affect the conduction of the PIN diodes thereby affecting or tuning the optimum operating frequency, the radiation pattern, and/or the impedance of the antenna. In a particularly advantageous configuration, the PIN diodes have lateral dimensions greater than or equal to one-tenth wavelength (.lambda./10) at the operating frequency. Distributed diodes have lower resistance and reactance than discrete or discrete monolithic diodes, thereby providing improved radiating characteristics, and have a relatively large power-handling capability which makes them useful for power transmission.

Abstract: A waveguide bandpass filter includes a fenestrated conductive septum which may be printed on a dielectric circuit board. The center frequency is tuned by a dielectric plate parallel with the septum and contiguous with the fenestrations which is movable in a direction orthogonal to the septum.

Abstract: A waveguide power combiner or splitter (divider) includes a common waveguide having an axis skewed relative to the axes of a line array waveguides. A sectoral parabolic reflector is oriented with its focus at a port of the common waveguide with its axis parallel with the axes of the waveguides of the array for reflecting signals from the focal point to create a locus of constant phase at the ports of the waveguide array, whereby signal power originating at the common waveguide is divided equally among the waveguides of the waveguide array. A waveguide power amplifier includes a power splitter as described above, and an amplifier module located in each waveguide of the waveguide array to amplify the power therein to produce amplified signal in an output waveguide array. The amplified signals from the amplifier modules are combined by a second reflector driven by the output waveguide array and reflected to a common output port.

Abstract: A switched-line type phase shifter employs a reference, uniform transmission line and a coupled exponential transmission line. The coupled exponential line network provides a different phase shift but provides a phase shift versus frequency characteristic that over a wide frequency band matches the reference line.

Abstract: A millimeter wave reflection phase shifter employs a fin-line structure within a waveguide network which has a central leg and four arms which together form two symmetric Y-junctions. The fin-line forms a septum within the waveguide and includes a conductive layer having a central gap or slot therein which extends along the leg and into each of the arms. Means for shorting the slot arms disposed at one end of the leg controls the phase shift experienced by a signal propagating through the phase shifter. This phase shifter may provide multiple selectable phase shifts.