摘要 |
<p>An improved oscillating circuit for use in microwave frequency bands has reduced power loss and is made smaller in vertical size. The local oscillating circuit includes an MMIC oscillator which comprises a FET (9), and a resonator (10) connected thereto so as to stabilize the oscillating frequency of the oscillator. The resonator is ring-shaped and arranged as close as several mu m to several tens of mu m to a predetermined position of a micro strip line forming a feedback loop connected to the FET forming the oscillator. Moreover, the resonator is a thin film formed by depositing a high-temperature superconducting material. As exemplary embodiments, YBCO, niobium and the like, can be used as high-temperature superconducting materials. Furthermore, a portion of the micro strip line, closest to the resonator, is concentrically disposed therewith to form a circular arc portion whose central angle is set at 90 degrees. <IMAGE></p> |