Abstract: A system for interference suppression onboard a satellite may include an antenna that is configured to receive uplink signals from a ground-coverage area and to generate a first signal. A spot-beam antenna may be configured to receive interference signals and to generate a second signal. A processor may be configured to receive the first signal from the antenna and the second signal from the spot-beam antenna and to perform a cross-correlation to generate a composite signal that includes a null at an interference frequency. The antenna may be a shaped reflector antenna and the spot-beam antenna may be a parabolic reflector antenna.

Abstract: A means and method to increase the beam traffic capacity, especially in high user density regions, of a multi-beam antenna communication system with multiple signals at any frequency transmitted (received) when in a transmit (receive) mode by canceling interference with neighboring signals. An interference cancellation network is provided for canceling the interference caused by the sidelobe(s) of at least one signal with one or more of the other signals in the network. Each power divider divides its input signal into one reference fractional signal and at least one non-reference fractional signal. Phase shifters/attenuators shift the phase and attenuate the amplitude of at least one of the non-reference fractional signals. Each power combiner combines its input reference fractional signal with at least one non-reference fractional signal into a composite signal emerging from the combiner. The phase/attenuation settings are selected to optimize the signal to interference ratio for each communications link.

Abstract: A means and method to increase the beam traffic capacity, especially in high user density regions, of a multi-beam antenna communication system with multiple signals at any frequency transmitted (received) when in a transmit (receive) mode by canceling interference with neighboring signals. An interference cancellation network is provided for canceling the interference caused by the sidelobe(s) of at least one signal with one or more of the other signals in the network. Each power divider divides its input signal into one reference fractional signal and at least one non-reference fractional signal. Phase shifters/attenuators shift the phase and attenuate the amplitude of at least one of the non-reference fractional signals. Each power combiner combines its input reference fractional signal with at least one non-reference fractional signal into a composite signal emerging from the combiner. The phase/attenuation settings are selected to optimize the signal to interference ratio for each communications link.

Abstract: In one aspect of the present invention, a transceiver includes a pair of antennas with one of the receive channels including a predetermined phase shifter for shifting one of the received signals prior to combining the received electromagnetic energy to form a combined signal for processing by a receiver. The amount of phase shift may be set to maximize the combined signal. The transceiver accounts for signal fading resulting from multiple path reflection, and is especially beneficial in a hand-held or mobile unit. In another aspect, an antenna system includes a pair of elongated quadrifilar antennas, which may be disposed so as to have their longitudinal axes parallel or coincidental as desired. A method for maximizing receipt of electromagnetic energy is also described along with a detector useful for determining the presence of information associated with electromagnetic energy.

Abstract: A near-field calibration arrangement for a phased-array antenna determines the phase shifts or attenuation of the elemental control elements of the array. The calibration system includes a probe located in the near field, and a calibration tone generator. The tone generator is coupled to the probe in the case of calibration of a receive antenna, and to the signal port of the array in the case of calibration of a transmit antenna. A code generator generates sets of values, with each set being orthogonal to the others. The codes are applied to the control input port of the array antenna, so that the codes encode the tone passing through the antenna. The encoded tones are applied to a decoder and processor, which processes the signals to determine the phase shift or attenuation associated with each bit of the control signal.

Abstract: A Tripulse method determines the orientation or attitude of a phased-array antenna located at a remote site, such as an aircraft or spacecraft. Three pulses are transmitted from the phased-array antenna in an estimated direction toward a coherent receiver, with a sum beam, and with first and second difference beams formed by reversal of the phase of certain elements above a first axis of symmetry, and to one side of a second axis of symmetry. The received signals are processed in a manner which determines the error between the assumed direction and the actual direction of the receiver. To determine the rotational position of the array antenna, the same steps are performed for a second remote receiver, and additional processing determines the complete attitude, including yaw, of the phased-array antenna. The coherent receiver may use the first transmitted pulse as a reference, or it may use a separate reference signal.