Abstract: The present invention provides for a low power receiver protector and stepped attenuator for conditioning a received input signal within a microwave receiver front end. The low power receiver protector includes a detector for generating a surge signal in response to the received input signal exceeding a predetermined threshold, a delay line for delaying the received input signal for fixed duration, and a limiter for reducing the voltage of the received input signal in response to the generation of the surge signal. The stepped attenuator includes a plurality of cells each having an attenuation transmission path which includes an attenuator for providing a predetermined amount of attenuation of the received input signal. Each attenuation transmission path, bypass transmission path and delay line comprise a high temperature superconductor to provide minimal loss and reduced size.

Abstract: A ghost canceller which operates at IF and utilizes a storage mode heterojunction acoustic charge transport device (SM-HACT). The signal delay provided by the SM-HACT is increased by the operation of barrier electrodes which delay the movement of charge packets across the device, thereby eliminating the need for additional digital equalization. The tap weights of the SM-HACT are determined by the operation of a fixed correlator which responds to ghosts in a predetermined training waveform.

Abstract: A segmented stretch waveform for wide band high duty cycle tracking application. The waveform is divided into multiples of two spaced segments as the tracking range closes. Target returns received during spaced segments are combined to correspond to the complete waveform; and range is determined in accordance with the combined waveform. Tracking range can be varied without changing bandwidth, FM slope, duty cycle or processing time.

Abstract: An IF Clutter Canceller using delay lines and acoustic charge transport (ACT) devices to subtract one interpulse period from another interpulse period. The first interpulse period is time demultiplexed with a tapped delay line and stored in ACT devices. The second interpulse period is time demultiplexed through the same delay line as was the first interpulse period. The stored time segments of the first interpulse period are released from the ACT devices and subtracted from the time demultiplexed time segments of the second interpulse period. The resulting clutter cancelled time segments are then assembled into a clutter cancelled interpulse period with a second tapped delay line.

Abstract: A surface acoustic wave device is disclosed which performs frequency channelization in a relatively small volume. The invention utilizes a wide band incline step frequency transducer each step feeding an independent beam width compressor waveguide combination. The waveguides fan out with a wide radius of curvature to contain the wave in off pure mode axis propagation. The output of each waveguide then feeds an independent beam width expander and frequency selector interdigital transducer. The use of the waveguides as a tapping and narrow aperture transport mechanism minimizes defraction, allows the output transducers to be widely separated achieving isolation and permits a larger number of filters per substrate.

Abstract: An acoustic surface wave signal transmission device includes a medium having a surface suitable for propagating acoustic energy or waves and having a first impedance characteristic. The surface of the medium includes an array of periodic discontinuities of a second impedance characteristic. The widths of the discontinuities vary in a predetermined manner to reflect a portion of said acoustic energy in proportion to the widths of the discontinuities. A transmitting transducer on said surface converts an input electrical signal into corresponding acoustic energy or waves and launches the energy or waves on said medium toward said array of discontinuities. The acoustic energy is reflected from said array of discontinuities toward a receiving transducer which converts the reflected acoustic energy or waves into a corresponding electrical signal.