A direct synthesis transmitter. A very efficient and highly linear direct synthesis
transmitter is provided that can be used to directly synthesize and transmit any
type of modulated signal. The direct synthesis transmitter includes a phase-locked
loop (PLL) with controls phase modulation plus an accompanying variable gain amplifier
for amplitude modulation. Also included is a system to align the phase and amplitude
modulation signals. A transmitter constructed in accordance with the present invention
is very efficient and suitable for use in portable radio equipment.