Patent ID: 7075378

Claim:
A cavity stabilized oscillator for producing an oscillating signal, comprising: a voltage controlled phase shifter (VCP) to receive a second signal and a third signal and to produce therefrom a first signal; a cavity to receive a fourth signal and produce therefrom the oscillating signal, said cavity having at least one cavity resonance mode; a power amplifier to receive the first signal and produce therefrom the fourth signal, said amplifier being disposed between the VCP and the cavity; and a feedback loop to receive the fourth signal and a reflection of said oscillating signal and produce therefrom the second signal, said feedback loop being disposed between the VCP and the power amplifier, wherein, said at least one cavity resonance mode is employed to satisfy at least one pre-determined oscillation condition in the feedback loop, and a phase noise due to the power amplifier is corrected by the VCP; and wherein: said second signal comprises a phase error between the oscillating signal and the at least one cavity resonance mode; and said at least one mode is selected by a bandpass filter disposed between the cavity and the VCP to receive the oscillating signal and provide the selected at least one cavity resonance mode as the third signal, wherein said cavity is a high-Q air/vacuum dielectric cavity.