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20 mJ, 1 ps Yb:YAG Thin-disk Regenerative Amplifier
Published on: July 12, 2017
A 300-MHz digitally compensated SAW oscillator
W D Cowan1, A R Slobodnik, G A Roberts
1Rome Air Dev. Center, Hanscom AFB, MA.
Summary
This study presents a digitally compensated surface-acoustic-wave (SAW) oscillator that significantly reduces temperature-induced frequency drift. The new method achieves precise frequency stability across a wide temperature range using digital circuitry and microprocessor control.
Area of Science:
- Electrical Engineering
- Materials Science
- Physics
Background:
- Surface-acoustic-wave (SAW) oscillators exhibit inherent temperature sensitivity, leading to frequency variations.
- Traditional compensation methods like ovens are bulky, power-hungry, and slow to stabilize.
Purpose of the Study:
- To develop a digital compensation method for SAW oscillators to mitigate temperature-induced frequency drift.
- To improve the stability and performance of SAW oscillators in variable temperature environments.
Main Methods:
- A digitally compensated SAW oscillator (DCSO) was designed and tested at 300 MHz.
- A novel temperature-sensing scheme using two SAW delay paths with differential temperature sensitivity on a single AT-cut quartz substrate was implemented.
- Microprocessor control and simple digital circuitry were employed for compensation.
Main Results:
- Frequency variation was reduced from +/-125 parts per million (ppm) to +/-1.4 ppm over a -23 to 75 degrees C temperature range.
- The digital compensation method effectively minimized thermal resistance and time-constant issues inherent in temperature sensing.
- The DCSO demonstrated advantages over ovenized systems, including fast warmup, reduced size, weight, and power consumption.
Conclusions:
- Digital compensation offers a highly effective and practical solution for stabilizing SAW oscillator frequencies against temperature fluctuations.
- This method presents a low-cost potential alternative to ovenized systems for applications requiring precise frequency control.
- The DCSO technology can compensate for other frequency drift sources beyond temperature variations.
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