Abstract: A sensor (10) for detecting an incident RF signal having a carrier frequency, and for estimating said carrier frequency, comprises a plurality of filters (70-73), each allowing passage of signals over a different band of frequencies from the band of frequencies over which passage of signals is allowed by the others of the plurality of filters (70-73), and a plurality of detectors (80-83). Each filter (70-73) is associated with at least one of the plurality of detectors (80-83), and said at least one detector (80-83) is arranged in use to generate an output signal if the incident RF signal results in a signal in the band of frequencies passed by the filter (70-73) with which the detector (80-83) is associated. Generation of the output signal by the detector (80-83) indicates in which of the frequency bands the incident RF signal has been detected.

Abstract: A sensor (10) for detecting an incident RF signal having a carrier frequency, and for estimating said carrier frequency, comprises a plurality of filters (70-73), each allowing passage of signals over a different band of frequencies from the band of frequencies over which passage of signals is allowed by the others of the plurality of filters (70-73), and a plurality of detectors (80-83). Each filter (70-73) is associated with at least one of the plurality of detectors (80-83), and said at least one detector (80-83) is arranged in use to generate an output signal if the incident RF signal results in a signal in the band of frequencies passed by the filter (70-73) with which the detector (80-83) is associated. Generation of the output signal by the detector (80-83) indicates in which of the frequency bands the incident RF signal has been detected.

Abstract: The invention comprises a feed horn (10) illuminating a circular flat panel (12) formed from a high impedance surface structure. By controlling the resonant frequencies of the individual elements of the array, a controlled phase shift profile is applied across the surface of the panel to an incident phase front spherically spreading from the feed antenna so as to reflect that wavefront in a particular direction or impose a certain desired beam shape. The principles are reciprocal so a receiving system can also be achieved or indeed a simultaneous transmit and receive operation can be supported. The phase controlled reflecting plate advantageously performs focussing to the feed and beam scanning or beam shaping. This concept of feed to a phased reflector plate allows the power distribution to be implemented in free space.

Abstract: The invention comprises a feed horn (10) illuminating a circular flat panel (12) formed from a high impedance surface structure. By controlling the resonant frequencies of the individual elements of the array, a controlled phase shift profile is applied across the surface of the panel to an incident phase front spherically spreading from the feed antenna so as to reflect that wavefront in a particular direction or impose a certain desired beam shape. The principles are reciprocal so a receiving system can also be achieved or indeed a simultaneous transmit and receive operation can be supported. The phase controlled reflecting plate advantageously performs focussing to the feed and beam scanning or beam shaping. This concept of feed to a phased reflector plate allows the power distribution to be implemented in free space.