Title :
Microwave oscillator phase noise reduction using negative resistance compensation
Author :
Lam, V.M.T. ; Yip, P.C.L.
Author_Institution :
Dept. of Electron. Eng., City Polytech. of Hong Kong, Kowloon, Hong Kong
Abstract :
Two microwave oscillators at a free-running frequency of approximately 800 MHz are designed. Both were designed to have the same feedback factors; the difference lies in the output loading circuit. By using the inverted common collector (ICC) configuration, a stable negative resistance is generated. This negative resistance is then used to compensate for the loss in the feedback path. Hence, a zero resistance loaded oscillator is implemented. A comparative study with experimental support confirmed that the zero loaded oscillator has a 6 dB and 18 dBc improvement in the phase noise and second harmonic rejection, respectively.
Keywords :
compensation; feedback; interference suppression; microwave oscillators; negative resistance; noise; solid-state microwave circuits; 800 MHz; UHF; feedback factors; inverted common collector; negative resistance compensation; output loading circuit; phase noise reduction; zero resistance loaded oscillator;
Journal_Title :
Electronics Letters
DOI :
10.1049/el:19930255
