The present invention is directed to providing a full duplex communication system capable of providing actual wireless transmission rates on the order of 125 Mb/s, or higher, with relatively high transmission power on the order of 0.5 to 2 watts (W) or higher, with a high signal-to-noise(S/N) ratio, a bit error rate on the order of 10.sup.-12 or lower, 99.99% availability, and with relatively simple circuit designs. Exemplary embodiments can provide these features using a single compact and efficient, low distortion transceiver design based on high power (e.g., 0.5 W) monolithic millimeter wave integrated circuits (MMICs), having a compression point which accommodates high speed modems such as OC-3 and 100 Mb/s Fast Ethernet modems used in broadband networking technologies like SONET/SDH (e.g., SONET ring architectures having self-healing ring capability). By applying high power MMIC technology of conventional radar systems to wireless duplex communications, significant advantages can be realized. Exemplary embodiments have transmit operating frequencies in a fixed wireless spectrum of 18-40 GHz or wider, and produce a power output on the order of 0.5 W to 2 W or more, with a relatively simple circuit design.

A method of employing multipath propagation in wireless radio communications uses an omnidirectional transmitting/receiving antenna at one end of a transmission link to send an interrogating signal across an environment subject to multipath disturbances to a phase-conjugating retrodirective antenna, and the retrodirective antenna returns a communication signal along the multiple pathways taken by the interrogating signal to the omnidirectional antenna despite the multipath disturbances. In a simplex communication mode, the retrodirective antenna sends a return signal mixed with a communication signal to the omnidirectional antenna. In a duplex communication mode, both an omnidirectional antenna and a phase-conjugating retrodirective antenna are operated in tandem at each end of the transmission link to provide effective two-way wireless radio transmissions.

A method of and apparatus for two-way radio meteor scatter communication amongst mobile transceiver-equipped terminals and fixed meteor scatter base terminal(s) that comprises communicating high volume point-to-point inbound information from the mobile terminals to the base terminal(s) and outbound information from the base terminal(s) to particular mobile terminals by radio meteor scatter, and broadcasting outbound information from the base terminal(s) to many mobile terminals by supplemental Loran communications short messages modulated upon Loran radio positional and navigation transmissions.

A meteor scatter communications system for communicating between a master station and one or more remote stations. In one exemplary embodiment, a broad beam transmitter probe signal is reflected from a meteor ionization trail to a remote station which then transmits a return data signal to the master station. The master station receiver has a plurality of antennas and a receiver beam forming network which forms a plurality of narrow beam receive signals, one of which has a high gain and corresponds to the narrow beam signal which illuminates the meteor trail and contains the reflected return data signal from the remote station. The master station processor selects such one narrow beam signal for processing the data therein. The transmitter at the master station, if desired, can then transmit a further narrow beam message signal containing a message to the remote station using a transmit beam forming network to provide a selected narrow beam transmit signal for reflection from the meteor trail to the remote station.

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.