A radio frequency transponder/repeater is provided wherein an array of receiving antenna elements is coupled to an array of transmitting antenna elements to provide a directional antenna system and including additionally an internal radio frequency source which is also coupled to the array of transmitting antenna elements. With such arrangement, an internally generated signal provided by the radio frequency source may be transmitted using the transmitting array of the Van Atta System.
This application is a continuation of application Ser. No. 930,029, filed Nov. 10, 1986, which is a continuation of Ser. No. 673,446, filed Nov. 20, 1984.
The invention relates to active repeaters for transmission systems used in mobile telephony. The active repeater comprises an antenna constituted by a plurality of juxtaposed radiating elements which are grouped together in two separate identical matrix arrays, amplification paths for connecting each radiating element of one array to the radiating element of the other array having the same matrix position, with each amplification path having identical gain and phase shift so that the wave received by the first array at an angle of incidence .theta. is retranmsitted by the second array as a wave having an angle of incidence .beta. such that .theta.=.beta.. The invention is applicable to mobile telephone systems.
A UMTS 3g repeater and a Multi Sector Directional LMU Antenna Array can be integrated to be deployed inside large structures and large moving vehicles such as ferries and trains.
A retrodirective interrogation responsive system wherein a responder, illuminated by an interrogator, receives an interrogation signal, modulates information onto the interrogation signal, and retransmits the encoded interrogation signal back in the direction of arrival of the collected interrogation signal. The responder uses a Van Atta array antenna and is capable of responding to an interrogator signal incident over a wide solid angle of arrival while retrodirectively retransmitting without amplification substantially all of the collected signal within a narrow solid angle. The responder may be implemented using monolithic microwave integrated circuit technology (MMIC), thus being suitable for high volume production.
A navigation system for a vehicle travelling along a highway that has an interrogator mounted on the vehicle and, a retrodirective transponder mounted alongside the highway for updating vehicle location. For collision avoidance systems, interrogators transmit and receive fore and aft, and transponders are mounted to respond to signals fore and aft of the vehicle. The transponder modulates information onto the interrogation signal, and retransmits the encoded interrogation signal back in the direction of arrival of the collected interrogation signal. The responder uses a Van Atta array antenna and is capable of responding to an interrogator signal incident over a wide solid angle of arrival while retrodirectively retransmitting without amplification substantially all of the collected signal within a narrow solid angle. The responder may be implemented using monolithic microwave integrated circuit technology (MMIC), thus being suitable for high volume production.
An antenna beam forming for generating a plurality of broad overlapping radiation beams for a cellular radio application comprises an antenna array having a plurality of individual antenna elements, each individual antenna element connected by a cable to a respective diplexor, each diplexor fed by a multi-channel power amplifier receiving an input from an output port of an eight way Butler matrix. Transmission signals are input to seven input ports of the Butler matrix, and output transmission signals are produced at four of the output ports of the Butler matrix. A remaining four output ports are each terminated with a respective matched load. A 3 dB power loss incurred in the Butler matrix is compensated by provision of a plurality of pre-amplifiers prior to the input ports of the Butler matrix, with the power amplification stage being carried out on the outputs of the Butler matrix. Side lobe suppression is maintained by ensuring phase and amplitude integrity across the output channels. A set of phase and amplitude adjusters operate on the output transmission signals from the Butler matrix output ports. The phase and amplitude adjusters may be electronically controlled.
