Vector FM modulator

Claim 1

A dual-mode transmitter alternatively operable in PSK and analog-FM states, adapted to receive a message signal, and comprising: A) a vector modulator, adapted to receive in-phase and quadrature modulating signals, for adding together in-phase and quadrature versions of a carrier in proportion to respective ones of the in-phase and quadrature modulating signals to produce a transmitter output; B) analog-state circuitry including: i) an integrating circuit for performing at least one signal-processing operation, including a time-integration operation, on the message signal when the transmitter is in the analog state to produce an integrating-circuit output; and ii) sine and cosine circuitry for generating analog-state quadrature and in-phase modulating signals respectively representing of the sine and cosine of the integrating-circuit output when the transmitter is in the analog state and applying the analog-state in-phase and quadrature modulating signals to the vector modulator; and C) PSK-state circuitry for generating from the message signal and applying to the vector modulator when the transmitter is in the PSK stage PSK in-phase and quadrature modulating signals that cause the vector modulator to produce a phase-shift-keyed version of the message signal.