Abstract: A radio wave receiving system comprises an antenna having at least two antenna elements, a phase shifter connected to at least one of the antenna elements, and a combiner for combining signals passed through the phase shifter and other signals not passed through the phase shifter. Through proper control of the mutual phase difference between signals from the aforementioned antenna elements by using the phase shifter, the system alters the polarization characteristic of the antenna in the direction of incidence of undesired reflected waves and consequently supresses the fading due to undesired reflected waves.

Abstract: The invention relates to a receiver for microwave signals--either emitted by a body or reflected therefrom--capable of analyzing the polar distribution of the signal strength by measuring the strength of the incoming signal after it had been passed through a horizontal, polarizing filter disk with three distinct transmission regions. One region transmits the entire signal reflected from a planar mirror positioned substantially at 45 degrees to the horizon and rotated on a vertical axis; the second and third regions in the planar electro-optical filter are defined by parallel grid lines, formed by electrical conductors opaque to the reflected radiation and aligned in mutually orthogonal arrays in the two regions respectively, so that each grid alignment becomes transparent to one polarization of the radiation incident thereon.

Abstract: A dual polarization transmission system includes a first circuit for alternately arranging a plurality of channels having a first bandwidth on a first polarized wave and a second polarized wave orthogonal to the first polarized wave on a frequency axis, and a second circuit for alternately arranging a plurality of channels having a second bandwidth smaller than the first bandwidth on the opposite polarized wave having the same center frequency as that of a corresponding one of the channels arranged by the first circuit.

Abstract: An adaptive depolarization-interference-compensator for a digital radio relay system using multi-level quadrature amplitude modulation (QAM) with co-channel operation of the orthogonally polarized signals which is not necessarily synchronous with the clock frequency and/or carrier frequency and produces good compensation of depolarization effects.The receiving branch of the two receivers (3, 4), which use the same RF-local oscillator (5) or separate RF-local oscillators are synchronized for the differently polarized signals and each contain a quadrature demodulator (8, 14) for two signal components (I- and Q-channel).

Abstract: A differential navigation system applicable to mobile users and covering a wide range geographic area, including remote regions. A reference receiver of known location tracks a navigation information service, computes differential data with respect to that information and communicates the data to a transmitting unit. The transmitting unit transmits differential data via a commercial geosynchronous earth satellite relay to a mobile user located no more than 500 miles from the reference receiver, but possibly located in a remote region. The mobile user receives the relayed signal with a non-directional, circularly polarized, non-stabilized antenna. Reception at a sufficient data rate with sufficient reliability is made possible by formatting the differential data using spread spectrum techniques.

Abstract: Method for measuring polarization of antennas utilizing three-antenna methods and far-field scanning techniques where the measured data is processed via digital Fourier transform. In one method, the normalized received phasor voltage for transmission between each of three antennas measured pairwise is digitally recorded as a continuously sampled function of relative roll angle between the antennas as one of the antennas is rolled in a continuous manner. The recorded data is digitally processed via a one-dimensional Discrete Fourier Transform to yield transformed quantities relating to the polarization of the antennas under test. From these quantities, standard polarization parameters including the circular polarization ratio, axial ratio, tilt angle and sense of the electric field polarization ellipse of each antenna may be obtained.

Abstract: A controllable dual input/output port power divider coupled with a controllable phase shifter feed a dual ported dual polarized microstrip antenna structure. By controlling the power divider and phase shifter, arbitrary orthogonal polarization (e.g., linear, circular or elliptical) radiated r.f. fields are obtained. Virtually the entire structure comprising the dual port power divider, phase shifter and microstrip radiator may be formed of shaped photo-chemically etched microstrip conductors disposed a very short distance (e.g., less than one-tenth wavelength) above a conductive reference surface.

Abstract: A terrestrial radio system which utilizes spot beams, time division multiple access and frequency reuse to provide communications services from a base station to remote customers within a system service region. The base station advantageously is arranged with multistage switching so as to permit the respective sharing of radio transmitters and receivers over larger number of antenna transmitting and receiving ports.

Abstract: A monopulse receiving arrangement is shown to comprise orthogonally polarized and electrically separate monopulse antenna arrays, one such array being made up of juxtaposed slotted waveguides and the other being made up of at least one monopulse array of dipoles printed on a dielectric material.

Abstract: A process and apparatus for the day-or-night monitoring of weather phenomena by means of the analysis of the movements of air masses, wherein the movements are determined by monitoring and receiving the multi-band VLF electromagnetic radiation generated in the atmosphere with directionally selective receivers. The received frequencies are then compared with values which have been correlated with atmospheric events. Means are provided for displaying the predictive results for events occurring up to 500 km away from the VLF receivers--typically updatable within seconds--in at least two stages according to the (near or far) range desired or the type of electrical polarization.

Abstract: A method and system is described for use with or in a satellite for compensating for cross coupling of satellite feeder link signals from a first channel of a first linear polarization as received by a first linearly polarized satellite antenna element with adjacent signals from a second channel. The second channel signals are at a generally orthogonal linear polarization. The system includes a second linearly polarized antenna element oriented orthogonal to the first antenna element for sensing the second channel signal, a gain controlled amplifier for reducing the gain of the second channel signal received at the second antenna element in inverse proportion to the sensed amount of cross coupling (depolarization) and adding the reduced gain signals that have been inverted to the first channel signals from said first antenna element.

Abstract: A radio communication system includes a transmitter unit, a transmission line and a receiver unit. The transmitter unit produces a vertically-polarized wave carrier or a horizontally-polarized wave carrier or both, in accordance with transmission data to be transmitted to the receiver unit. The receiver unit discriminates the levels of the thus transmitted vertically- and horizontally-polarized wave carriers to reproduce the original data.

Abstract: A technique for reducing cross-polarized signals in the axis of four-port al-polarized antennas. The resulting lower cross-polarized signals reduce a tracking antenna's susceptibility to tracking errors and to breaklocks. Some energy from the transmission line connected to the (V) port is coupled, after proper attenuation and phase adjustment, and transmitted through the (H) port, thereby nulling out the (V) cross-polarized pattern.