Analysis and synthesis of high-frequency transistor oscillators with a wideband negative feedback

Various circuit designs of high-frequency bipolar transistor oscillators with a feedback resistor in the emitter circuit are considered. Isochronism and quasi-isochronism conditions are established, which, when fulfilled, bring noise oscillator characteristics close to the best possible ones. A condition for choosing generalized circuit parameters is formulated that complies with the maximum efficiency requirements for the oscillator steady-state and self-excitation modes. In order to solve the synthesis problem, oscillator immitance characteristics are studied as a function of generalized circuit parameters for various relative locations of the load resistor and resonator. As a result, circuit designs are recommended for practical application that provide the highest control potentialities. Relationships obtained in this paper are validated by an example of designing a 1.6-GHz oscillator optimized from the viewpoint of frequency stability.