| 摘要 |
An oscillator (10) operational in the millimeter wave range including frequencies greater than 30 GHz includes a lumped element active circuit (12) including an active element (14) with a negative resistance, a lumped element resonator circuit (16) in parallel therewith, and an antenna (18) extending directly from the oscillator without an intermediate impedance matching section therebetween and without an isolation element therebetween. The antenna has a length of nominally a quarter wavelength at the desired fundamental frequency, and has zero connection length from the oscillator. The antenna serves a dual function of radiating the energy generated by the oscillator and also transforming the output impedance of the oscillator to the impedance of transmission media providing a load, such as free space or a wave guide. The antenna is spaced rearwardly of a front housing wall having a resonant iris output port designed to be parallel resonant at the fundamental frequency, such that the iris functions to transmit energy generated by the oscillator at the fundamental frequency, and to appear as a low impedance shunt at the second harmonic to suppress the transmission of energy generated at the second harmonic. The antenna is spaced forwardly of a back housing wall by a distance of nominally a quarter wavelength at the second harmonic, such that the back wall provides a short circuit. The invention includes application not only in existing fixed oscillator and VCO technology, but also in spatial power combining technology.
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