Francis Robert Steel

Frequency division multiplexed acknowledge back paging system

High data rate simulcast communication system

Acknowledge back paging system having the capability of matching variable length data messages to pager addresses

Acknowledge back pager with adaptive variable transmitter output power

Acknowledge back pager with apparatus for controlling transmit frequency

Adjustable antenna arrangement for a portable radio

Spectrally efficient digital modulation method and apparatus

Digital detection system for differential phase shift keyed signals

Extended phase-range, high fidelity modulator arrangement

Switching amplifier system