Title :
A low-noise, multiple-frequency oscillator utilizing large numbers of electronic switch-selectable crystals
Author :
Driscoll, M.M. ; Matthews, N.
Author_Institution :
Westinghouse Electr. Corp., Baltimore, MD, USA
fDate :
31 May-2 Jun 1989
Abstract :
The design and performance are reported of an oscillator incorporating 16 PIN diode switch-selectable, fifth-overtone crystals operating in the 100-MHz range. A lumped-element, quarter-wavelength line provides a means for absorption of the printed wiring board track connections and switch parasitic reactances for the 15 switched-off crystals. PIN (rather than Schottky) diodes were utilized because they have lower off-state capacitance and PIN diode use has no measurable degrading influence on oscillator signal phase noise performance. Oscillator flicker of frequency noise is characterized by Sy(100 Hz)=3×10-25 and is due to short-term instability in the resonators themselves. The pulse noise floor level is -169 dB/Hz. Using modest levels of excess gain, interchannel frequency switching time is on the order of 2 ms, compared to 9-ms turn-on time
Keywords :
crystal resonators; noise; radiofrequency oscillators; switching; variable-frequency oscillators; 100 MHz; PIN diode switch-selectable; PWB track connections; VHF; electronic switch-selectable crystals; fifth-overtone crystals; frequency noise; low-noise; lumped element line; multiple-frequency oscillator; printed wiring board; pulse noise; quarter-wavelength line; short-term instability; signal phase noise performance; switch parasitic reactances; 1f noise; Absorption; Capacitance measurement; Crystals; Frequency; Oscillators; Parasitic capacitance; Schottky diodes; Switches; Wiring;
Conference_Titel :
Frequency Control, 1989., Proceedings of the 43rd Annual Symposium on
Conference_Location :
Denver, CO
DOI :
10.1109/FREQ.1989.68838
