Title :
Thin-film YIG oscillators with low phase noise and high spectral purity
Author :
van der Weide, D.W.
Author_Institution :
Watkins-Johnson Co., Palo Alto, CA, USA
Abstract :
Two broadband bipolar thin-film YIG oscillators have been developed, one having frequency coverage of 2.7 to 7.5 GHz with phase noise of -109 dBc at 10 kHz from the 3.0 GHz carrier. Another 0.5 to 2.0 GHz circuit exhibits -55 dBc second harmonic levels and is much more stable than a similar YIG-sphere circuit. The author discusses the design and measurement of thin-film resonators, as well as practical improvements that stabilize thermal drift. The circuits discussed could be improved with better magnet structures and with buffer amplifiers to increase output power. Thermal drift has been largely countered with appropriate slab heating, much as is currently done with spheres, while the novel heater structure also promotes adjustment of coupling.<>
Keywords :
bipolar transistors; garnets; magnetostatic wave devices; microwave oscillators; resonators; solid-state microwave circuits; yttrium compounds; 0.5 to 7.5 GHz; YFe5O12; bipolar transistor oscillators; broadband oscillators; buffer amplifiers; design; frequency coverage; garnets magnetostatic wave resonators; heater structure; magnet structures; measurement; phase noise; second harmonic levels; slab heating; spectral purity; thermal drift stabilization; thin-film YIG oscillators; thin-film resonators; Frequency; Heating; Magnetic circuits; Oscillators; Phase noise; Power amplifiers; Power generation; Slabs; Thin film circuits; Transistors;
Conference_Titel :
Microwave Symposium Digest, 1992., IEEE MTT-S International
Conference_Location :
Albuquerque, NM, USA
Print_ISBN :
0-7803-0611-2
DOI :
10.1109/MWSYM.1992.187975
