Abstract: A circularly polarized phased array antenna system for both reception and transmission applications includes a plurality of planar radiating (or receiving) elements, a switching matrix for each radiating element, a beamforming network and a transmit/receive module. Each planar element includes 4.times.N radially disposed segments that may be selectively connected with the four modes of a circularly polarized signal such that two opposing segments function as the two respective arms of a dipole radiating element and two orthogonal such dipoles function as a crossed pair of dipoles for receiving or transmitting the circularly polarized signal. The switching matrix and the beamforming network cooperate to determine the polarization phase of the radiating element by commutating the four modes of the circularly polarized signal to any four orthogonal segments of the radiating element.

Abstract: Synaptic antennas or other radio frequency interactive systems variable in response to photon energy stimuli, are provided from a three-dimensional matrix of electrically conductive segments with photoresponsive devices selectively separating numerous adjacent segments from each other and alternatively interconnecting segments with each other in response to photon energy stimuli. Photon energy stimuli supplied to a first array of photoresponsive devices provide a first combination of interconnected segments constituting a first radio frequency interactive configuration in the matrix. Conversely, photon energy stimuli supplied to a second array of the photoresponsive devices provide a second combination of interconnected segments constituting a second radio frequency interactive configuration in the matrix.

Abstract: An automatic minimum discernible signal level analyzer for evaluating the low signal level detecting capabilities of a pulse-type receiver and including an RF frequency source phase-locked to the radar transmitter frequency and capable of being adjusted in power output by circuitry which automatically measures the statistical noise content of the receiver video and adjusts the power output of the RF source so that the video signal meets preset values of probability of false alarm and probability of detection, the absolute RF power being then a direct measure of the minimum discernible signal sensitivity of the receiver under test.

Abstract: Compandor apparatus including a compressor comprised of an operational amplifier having a plurality of gain controlling feedback paths that are respectively responsive to different portions of the input frequency spectrum, and an expandor comprised of an operational amplifier having a plurality of gain controlling circuits that are respectively responsive to different portions of the input frequency spectrum.

Abstract: A low noise discriminator circuit having particular utility for use in determining the spectral purity characteristics of an rf signal source and comprising, in addition to standard discriminator components, a down-locked reference signal source including a voltage-controlled signal generator for developing a reference signal and a corresponding train of signal pulses, a stabilizing voltage-controlled oscillator which responds to the discriminator error signal and generates a stabilizing signal having a frequency at least an order of magnitude greater than the frequency of the reference signal, and a sampling phase detector which samples the stabilizing signal at the signal pulse frequency and develops a control signal which is fed through a feed-back loop to stabilize the reference signal generator.

Abstract: A signal delay apparatus for delaying an information signal and including a bucket brigade device for sampling the signal and time delaying the samples, a sample-and-hold device for sampling and storing the voltage levels of the individual delayed samples in succession, and a clock for developing timing signals for controlling the delay line and the sample-and-hold device.

Abstract: A threshold extension device for use in a frequency modulation demodulator circuit to minimize effects of impulse noise, usually referred to as "clicks", which normaly appear in the demodulated output signal, and including a delay line for delaying the demodulated signal, a follow and hold circuit for selectively omitting the click impulses from the delayed signal, a detector for detecting the occurrence of an event which will give rise to a click impulse in the demodulated signal, and a detector driven control signal generator for controlling operation of the follow and hold circuit.

Abstract: An improved squelch circuit for FM demodulators including a low pass filter for filtering out-of-band noise from the demodulator output signals, a delay line for time delaying the filtered signals, a gate for selectively passing the filtered demodulated output signals to an output terminal, and a control circuit for controlling the gate. The control circuit includes a high pass filter for passing the out-of-band noise in the demodulated signals, a detector for detecting the noise level of the noise passed by the high pass filter, and a comparator for comparing the detected out-of-band noise level to a reference to develop a gate control signal which causes the gate to be opened when the out-of-band noise level is relatively low and to be closed when the out-of-band noise level is relatively high.

Abstract: A transceiver comprising a transmit circuit for receiving a transmit audio frequency signal from a voice input transducer and including a delay line for delaying the transmit audio frequency signal, a modulator for converting the delayed transmit audio frequency signal to a transmitable radio frequency signal and a first switchable attenuator responsive to a control signal and operative to selectively couple the radio frequency signal to an output terminal for transmission; a receive circuit for receiving a responsive radio frequency transmission and including a demodulator for converting the received radio frequency signal to a received audio frequency signal, and a second switchable attenuator responsive to the control signal and operative to selectively couple the received audio frequency signal to a voice output transducer; and a control circuit including a transmit detector for detecting the transmit audio frequency signal level, a receive detector for detecting the received audio frequency signal level,