A new systematic method is presented for the
design of high-efficiency microwave oscillators. It is
based on the control of the transistor output-voltage
waveform, through the combined use of a nonperturbing
auxiliary generator and a substitution generator. The
nonperturbing generator sets the oscillation frequency at
the desired value during the entire design process. The
combination of the two generators allows obtaining a
quasisquare output-voltage waveform, with optimum
harmonic components to maximize the efficiency.
Attention is paid to the stability and phase noise of the
implemented oscillator, which are analyzed versus
technological parameters. A 6-GHz oscillator has been
designed using these techniques, with good experimental
results
