초록 ▼

An antenna (50) is disclosed herein whose phase center may be electrically moved relative to a main receiving/radiating element. The main receiving element (56) is located in a cavity (54) in a ground plane (52). Spaced around the main receiving element are a number of paracletic elements (58, 60, 6

An antenna (50) is disclosed herein whose phase center may be electrically moved relative to a main receiving/radiating element. The main receiving element (56) is located in a cavity (54) in a ground plane (52). Spaced around the main receiving element are a number of paracletic elements (58, 60, 62, 64), each of which has at least two switchable reactance states. In one state, there is little coupling between the paracletic element and the main receiving element. In another state, coupling is increased so that the phase center of the antenna shifts towards the paracletic element. A sequencer (100) supplies bias voltages to switching diodes (84, 86) to control the reactance states of the paracletic elements and thus the position of the phase center of the antenna. The antenna may be used as a tracking feed (14) for a directional lens or reflector system (12).

대표청구항 ▼

A tracking antenna including electromagnetic energy directing means for directing electromagnetic energy to or from a vertex, and a tracking feed located at said vertex, said tracking feed comprising primary radiating/receiving means for receiving or transmitting electromagnetic energy and having a

A tracking antenna including electromagnetic energy directing means for directing electromagnetic energy to or from a vertex, and a tracking feed located at said vertex, said tracking feed comprising primary radiating/receiving means for receiving or transmitting electromagnetic energy and having a unidirectional radiating pattern, a plurality of paracletic means fixedly positioned about said unidirectional radiating pattern of said primary radiating/receiving means, each having at least two selectable impedance states for controllably shifting the position of the phase center of said tracking feed relative to said directing means, and means for controlling said impedance states of said plurality of paracletic means so as to shift the position of said phase center in a known manner, whereby a signal received by said primary radiating/receiving means is modulated by said controlled phase center shifting and may be processed to derive tracking information therefrom.