J. T. Harvey, MIEEE1 and A. C. Young, MIEEE2
1. Mimix Broadband, 520 W. NASA Road One, Webster, Texas 77598 USA
(Previously at Tadiran Microwave Networks, 4000 Greenbriar, Stafford, Texas 77477 USA)
2. CSIRO Telecommunications & Industrial Physics, PO Box 76, Epping, NSW, 1710 Australia.
This paper outlines a new approach to the design of phase locked oscillators suitable for integration into microwave radios where tunability and low phase noise are required.
Most microwave oscillators available in the marketplace are based on single transistor, negative resistance designs, and use varactors with dielectric resonators (DROs) or integrated transmission line resonators , or YIG resonators for tuning. DROs have restricted tuning range, integrated resonators have low Q factors which causes poor phase noise, and the high performance of YIG resonators is obtained at significant cost and power consumption.
Nearly all texts on oscillators introduce the topic by analyzing a two port amplifier with feedback provided by a band-pass filter , and Leeson's noise model  assumes a linear feedback structure for analysis. Such structures have been used for practical oscillators , but generally where there was some specialist application . In the world of discrete components, the complexity of high frequency feedback structures is too great, particularly given the need for phase control within the feedback loop....
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