| 摘要 |
A high-frequency voltage-Controlled oscillation circuit which does not oscillate abnormally, is improved in phase noise, and has a small circuit scale. A phase shift circuit composed of third or more order odd À low-Pass filter and capacitive variable-reactance elements (D1, D2)connected to the input and output of the low-pass filter in series respectively is inserted in a feedback loop of a transistor of an oscillation amplifier circuit. The low-pass filter is composed of an inductive reactance element (L3) connected to the feedback loop in series and capacitive variable-reactance elements (D4, D5) parallel connected to the input and Output of the inductive reactance element (L3). The inductive reactance element (L3) is a C-Shaped, a donut-Shaped , or a U-Shaped microstrip line. Thus, a high-frequency voltage-Controlled oscillation circuit is realized. |
