Multiple radio channel frequency signals that are modulated with respective
information modulation are transmitted from a common antenna at multiple radio
frequencies. Multiple modulators are provided, a respective one of which corresponds
to a respective one of the radio channel frequencies. Each modulator generates
at least one constant amplitude, phase modulated drive signal at the corresponding
radio channel frequency from the respective information modulation, such that the
at least one constant amplitude, phase modulated drive signal corresponds to the
information modulation for the corresponding radio frequency. At least one saturated
power amplifier is provided for each of the at least one constant amplitude, phase
modulated drive signals. A respective saturated power amplifier is responsive to
the corresponding constant amplitude, phase modulated drive signal, to produce
a corresponding amplified output signal at an output thereof. A coupling network
connects the outputs of the saturated power amplifiers in series, to produce a
combined signal that is applied to the common antenna, such that the common antenna
radiates the radio channel frequency signals that are modulated with the respective
information modulation. In first embodiments, the at least one constant amplitude,
phase modulated drive signal is a single constant envelope modulation drive signal,
wherein the information modulation is a constant envelope information modulation.
In other embodiments, at least two constant amplitude phase modulated drive signals
are provided at the corresponding radio channel frequency, such that the at least
two constant amplitude, phase modulated drive signals correspond to the information
modulation for the corresponding radio frequency.
