Surface acoustic wave oscillator
US4871984A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 24, 1988 |
| Grant date | Oct 3, 1989 |
| Priority date | — |
| Expiry date | Jun 24, 2008 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03B5/326
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A microwave surface acoustic wave resonator stabilized oscillator includes an amplifier having an input terminal and an output terminal and a feedback circuit disposed around said amplifier for providing a closed loop about said amplifier having an integral multiple of 2.pi. radians of phase shift and excess small signal gain at a frequency f.sub.o. The SAW resonator is disposed in the feedback means and is selected to operate in a fundamental mode of operation and provides a resonant circuit having a resonant frequency f.sub.o. The feedback circuit around the amplifier causes the loop to oscillate at a frequency at which the phase shift is an integral multiple of 2.pi. radians and which has excess small signal gain. As the circuit starts to oscillate, the overall gain in the loop is compressed and the loop amplifier is forced to operate in a non-linear region. Operation in non-linear region causes the amplifier to generate harmonics of the fundamental frequency and thus, by providing a circuit which extracts the harmonics of the fundamental frequency, rather than the fundamental frequency itself, the frequency range of the amplifier can be extended. Furthermore, by keeping the fun…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.