Abstract: The present invention reduces the distortion components produced from high power level mixing through a set of adaptive cancelling circuits which utilize a low power level mixing of the same signals to provide a signal which is adaptively cancelled with a signal representative of the high power level signal including distortion to provide an output signal which comprises substantially only the distortion components found in the high power level signal. These distortion components are then adaptively cancelled or combined with the high power level signal including distortion to provide an output signal which comprises the primary signal and insignificant levels of noise and distortion.

Abstract: Circuitry for controlling the intermediate frequency of an FM receiver comprising modulating means for frequency modulating the intermediate frequency signal with a modulating signal of predetermined frequency; detecting means for detecting the absolute amount of distortion incurred by the modulating signal of predetermined frequency at the intermediate frequency amplification stage of the FM receiver; and control means for changing the intermediate frequency by incremental amounts to control the intermediate frequency so that the distortion at the intermediate frequency amplification stage is minimized in accordance with the increase or decrease in the distortion detected by the detecting means.

Abstract: A data modulated carrier is branched into two orthogonal components and as a result of correlation with a difference signal supplied to a receiver, first and second regulating signals are produced. The first and second regulating signals each regulate a base band simulation stage to produce respective dummy signals, taking into account the two orthogonal signal components, and form components of a compensation signal which is used to suppress a cross-talk signal which is superimposed on a signal received from a remote station.

Abstract: A cross polarization compensation system, in which an input elliptically polarized wave is converted, by a first rotatable differential phase shifter having a phase shift of 90.degree. or less than 90.degree., into an elliptically polarized wave defined by.vertline..alpha..vertline.=.vertline.cot.sup.-1 .gamma..vertline.(where .alpha. is the tilt angle of an ellipse indicative of the elliptically polarized wave relative to a predetermined reference direction and .gamma. is the axial ratio for the ellipse), and then the phase delay or advance plane of a second rotatable differential phase shifter having a phase shift of the ellipse indicative of 90.degree. is disposed in alignment with the major axis of the converted elliptically polarized wave, thereby to obtain a linearly polarized wave having electric fields components of a desired direction.

Abstract: An automatic gain control for a receiver includes a gain controller for controlling the gain of the receiver, a control device connected to the tuning device of the receiver for varying and controlling the tuning frequency of the tuning device, and a level detector connected to the control device and the receiving signal system of the receiver for detecting the receiving level. The control device includes a calculation processor connected to the tuning device, the level detector and the gain controller, and the calculation processor includes a detector for detecting the absence or presence of other broadcasting waves (interference waves) in a predetermined relation with the receiving frequency of the receiver and for controlling the gain controller in such a manner as to reduce the gain thereof when the signal intensity of the interference broadcasting waves exceeds a predetermined level predetermined by the level detector.

Abstract: A single sideband receiver translates the frequencies of a received signal composed of a data signal and a pilot tone to predetermined intermediate frequencies. Filters separate the intermediate frequency data signal and the intermediate frequency pilot tone. The frequency of the intermediate frequency pilot tone is translated to a frequency sufficiently removed from the frequency spectrum of the intermediate frequency data signal so as not to interfere therewith. The translated, intermediate frequency, pilot tone and the intermediate frequency data signal are amplified by a single automatic gain controlled amplifier. A demodulator produces audio output signals and a recovered pilot tune in response to the output signal of the amplifier. The recovered pilot tone is input to a pilot regenerator. The output signal of the pilot regenerator is input to the demodulator. The recovered pilot tone is also input to an automatic gain control circuit.

Abstract: The invention is used in a receiver for a communication system, which transmits periodically occurring digital signals over a pair of orthogonally related polarized waves. Horizontal signals from one of the orthogonal waves are applied to a first input terminal of an equalizer in the receiver. Vertical signals from the other of the orthogonal waves are applied to a second input terminal. An individually associated, cascaded plurality of delay circuits is coupled to each of the input terminals. The delay in each of the delay circuits is equal to the time spacing between the occurring signals. Therefore, a plurality of the recurring digital signals appear simultaneously at the outputs of each of the delay circuits. A variable attenuator, individually associated with the output of each delay circuit, is adjusted to pass an incremental signal responsive to each of the occurring signals appearing simultaneously at the outputs of the delay circuits.

Abstract: Apparatus and method for controlling the crosspolarization of signals in a satellite communications, frequency reuse system. Each earth station in the system includes one crosscoupling network that compensates for the crosspolarization of signals transmitted by such earth station uplink to the satellite due to the propagative medium around such earth station, and an adaptive feedback control system having another crosscoupling network that compensates for the crosspolarization of signals received from the other earth stations due to such propagative medium around such earth station.

Abstract: A double-sideband amplitude modulated (DSBAM) carrier passed through band-pass circuits wich are too narrow for the modulated carrier or are misaligned, may have one or both side-bands altered in relative amplitude, or in phase relative to the carrier. These effects result in amplitude modulation distortion and produce angle modulation of the carrier, with the same waveform as the amplitude distortion. In this invention the angle modulation is detected and applied to an amplitude modulator in the required phase and amplitude to substantially eliminate the distortion of the modulated carrier.

Abstract: An adaptive interference reduction system for removing cross talk from a dual polarization system comprising a first adjustable filter for varying the phase and the weight of a first input signal, a second adjustable filter for varying the phase and the weight of a second input signal, a first adder for adding this first input signal and the weighted and phase adjusted output from the second adjustable filter, a second adder for adding the second input signal and the weighted and phase adjusted output from the first adjustable filter, a first noise-to-signal measuring device for generating a signal proportional to the noise-to-signal ratio in the output signal from the first adder, a second noise-to-signal measuring device for generating a signal proportional to the noise-to-signal ratio in the output signal from the second adder, and a dither-type control logic for dithering in-phase and quadrature square-waves in accordance with the signals generated by the first and second noise-to-signal measuring devices

Abstract: A cross-talk component cancellation circuit is used in an angle-modulated wave signal transmission system for transmitting first and second angle-modulated wave signals of at least two channels, wherein a cross-talk component of the second angle-modulated wave signal is admixed in the first angle-modulated wave signal.