A dual band user terminal (10) includes a controller (18) for outputting a
BAND signal for specifying operation in one of a first frequency band or a
second, higher frequency band; a single frequency synthesizer (46) that is
responsive to the BAND signal for outputting an RF signal in one of two
frequency bands; and an RF transceiver (11) comprising a dual band
receiver that receives RF signals in the first frequency band and in the
second, higher frequency band, and a dual band transmitter that transmits
RF signals in the same frequency bands. The dual band receiver includes a
first receiver chain that operates in the first frequency band as a single
conversion receiver having a downconversion mixer that is preceded by a
first filter and that is followed by second filter, and a second receiver
chain that operates in the second frequency band as a dual conversion
superheterodyne receiver having a first downconversion mixer preceded by a
first filter and followed by a second filter coupled to a second
downconversion mixer followed by a third filter. The downconversion mixer
of the single conversion receiver is also the second downconversion mixer
of the dual conversion superheterodyne receiver, and the second filter of
the single conversion receiver is also the third filter of the dual
conversion superheterodyne receiver. The dual band transmitter includes a
modulator that outputs a modulated RF signal. When operating in the first
frequency band the input RF signal to the modulator has a frequency that
is equal to the transmitted RF signal, and when operating in the second
frequency band the input RF signal has a frequency that is equal to one
half of the transmitted RF signal.