Patent ID: 7932789

Claim:
A frequency adjustable surface acoustic wave oscillator comprising: a piezoelectric material; a plurality of transmitting fingers interfacing with a first portion of the piezoelectric material, the plurality of transmitting fingers configured to initiate a surface acoustic wave on the piezoelectric material; a plurality of receiving fingers interfacing with a second portion of the piezoelectric material, the plurality of receiving fingers configured to receive the surface acoustic wave and generate an electrical signal; a plurality of phase adjustable drivers, each of the plurality of phase adjustable drivers having a driver input and a driver output, the driver output of each of the plurality of phase adjustable drivers connected to one of the plurality of transmitting fingers; each of the plurality of phase adjustable drivers further comprising: a driver summing block having inputs and an output; a first adjustable gain amplifier having an input and an output, the input connected to the driver input, the output connected to an input of the driver summing block; a second adjustable gain amplifier having an input and an output, the input receiving a phase-shifted version of the driver input via a phase-shifter, and the output connected to an input of the driver summing block; and the output of the driver summing block connected to the driver output of the phase adjustable driver; a plurality of phase adjustable receivers, each of the plurality of phase adjustable receivers having a receiver input and receiver output, the receiver input connected to one of the plurality of receiving fingers; a receiver summing network adapted to sum the receiver output from each of the plurality of phase adjustable receivers and produce a receiver summed output; and a gain element adapted to receive the receiver summed output, the gain element having an output adapted to excite the driver inputs.