A novel surface acoustic wave resonator for compact, low-cost oscillators

A three-port SAW (surface acoustic wave) resonator-filter was developed as the frequency-stabilizing component in a low-cost oscillator operating at 445 MHz. It fulfils the additional tasks of adjusting the loop phase in a Pierce oscillator design, partitioning the power between oscillator loop and output, and filtering the output signal. It thereby substantially reduces the size, complexity, and cost of the oscillator. The filter was combined with a commercially available integrated amplifier to create a self-contained, two-chip oscillator. The two chips are mounted on a TO-39 header. All electrical connections are made by wire bonding; no circuit board is necessary. With the amplifier used, the output power is 0 dBm at 6-V supply voltage. All spurious oscillations are suppressed by more than 40 dB.<>