A series of microwave resonant oscillator sensors were designed and characterized using bandpass planar and volumetric electrical resonators having loaded quality factor (Q) values in the range of 2 to 20. The use of these resonators in positive feedback circuits yielded sensor Q-factors of up to 2 x 107, demonstrating Q-factor amplifications on the order of 106. It is shown that the Q-factor amplification can be increased in a positive feedback system through the selection of feedback loop group delay, allowing use of resonators with lower Qstat values. A low-frequency electromagnetic interference sensing application is demonstrated for two resonant oscillator configurations, showing considerable frequency sensitivity to 45 kHz emitters.
Revised: September 30, 2014 |
Published: June 23, 2014
Citation
Jones A.M., J.F. Kelly, J.R. Tedeschi, and J.S. McCloy. 2014.Design Considerations for High-Q Bandpass Microwave Oscillator Sensors Based Upon Resonant Amplification.Applied Physics Letters 104, no. 25:Article No. 253507.PNNL-SA-102899.doi:10.1063/1.4885077