A Microwave FET Oscillator Design Approach and Its Application in an Injection Locked Oscillator

摘要

A low power 14 GHz MIC GaAs FET oscillator was designed. The analytical model of the oscillator and design approach used are discussed in detail. A shunt feedback oscillator configuration was employed. Approximations were made to account for FET large signal effects in the design for maximum oscillator output power. An expression relating oscillator output power to feedback loop loss is presented. The requirement for filtering in the feedback loop is discussed. Experimental results were compared with theory and found to be in good agreement. Output power was 10 dBm at 14.0 GHz. The injection locked characteristics of the oscillator were experimentally investigated. It was found that for a 15 dB injection gain, the locking bandwidth was 69 MHz. The FM noise properties and transient performance of the injection locked oscillator are presented.