High frequency oscillator using transmission line resonator

A high frequency oscillator comprising:

• a transmission line resonator having a midpoint which serves as a null potential point;
• a pair of active devices for oscillation respectively connected to a pair of resonance wave points for said transmission line resonator, said resonance wave points being in a mutually opposite-phase relationship;
• and
• a plurality of output lines each having one end connected to said transmission line resonator at a point symmetric to said midpoint, and the other end commonly connected to a connection, wherein:
• said pair of active devices share said transmission line resonator as a high frequency resonator to make up a pair of oscillation systems which oscillate in opposite phases to each other at a fundamental frequency depending on length of said transmission line resonator,
• a standing wave of an even-order harmonic of said fundamental frequency has one of maximum displacement distribution points at said midpoint on said transmission line resonator,
• said plurality of output lines are coupled to said transmission line resonator respectively at maximum displacement distribution points for a standing wave of an 2n-th harmonic on said transmission line resonator, said standing wave being in opposite phase to that at said midpoint, where n is an integer equal to or larger than two, and
• even-order harmonic components of 2(n−1)-th or lower are suppressed at said connection.