Acoustic surface wave devices having improved performance versus temperature characteristics

Claim 2

An acoustic surface wave delay line comprising: a substrate of piezoelectric material having a plurality of surface regions of different crystallographic orientations; at least one transmitting transducer disposed on one of the surface regions for propagating an acoustic surface wave having a first phase-shift response versus ambient temperature characteristic; at least one receiving transducer disposed on another of the surface regions a predetermined distance from the transmitting transducer for receiving a propagated acoustic surface wave having a second phase-shift response versus ambient temperature characteristic; and coupling means coupled to the transmitting and receiving transducers for coupling the acoustic surface wave from one of the surface regions to another of the surface regions to provide at the receiving transducer an output signal having a phase-shift response versus ambient temperature characteristic equal to the combination of the first and second phase-shift response versus ambient temperature characteristics.

Claim 3

An acoustic surface wave delay line as in claim 1 wherein: the plurality of surface regions includes a first and a last surface regions, and each of said plurality of surface regions having transmitting and receiving transducers disposed thereon for propagating acoustic surface waves, each of said waves having a phase-shift response versus ambient temperature characteristic; the coupling means couple the receiving transducer on one surface region to the transmitting transducer on another surface region unless the receiving transducer is on the last surface region or unless the transmitting transducer is on the first surface region; and the output signal has a phase-shift response versus ambient temperature characteristic equal to the combination of all of the phase-shift response versus ambient temperature characteristics.

Claim 4

An acoustic surface wave delay line as in claim 1 wherein: the substrate of piezoelectric material has first and second surface regions, the second surface region being cut at a different crystallographic orientation than the first surface region; the transmitting transducer is disposed on the first surface region of the piezoelectric material; the receiving transducer is disposed on the second surface region of the piezoelectric material; the coupling means includes a receiving transducer disposed on the first surface region a predetermined distance from the transmiTting transducer for receiving the acoustic surface wave therefrom, a transmitting transducer disposed on the second surface region a predetermined distance from the receiving transducer for transmitting the acoustic surface wave thereto, and a first amplifier having an input port connected to the receiving transducer on the first surface region and an output port connected to the transmitting transducer on the second surface region for coupling the acoustic surface wave from the first to second surface region.

Claim 5

An acoustic surface wave delay line as in claim 1 wherein the acoustic surface wave propagated on one of the surface regions also has a first frequency response versus ambient temperature characteristic, the acoustic surface wave propagated on another of the surface regions also has a second frequency response versus ambient temperature characteristic, and the output signal has a frequency response versus ambient temperature characteristic equal to the combination of the first and second frequency response versus ambient temperature characteristics; and further including a second amplifier having an input port connected to the receiving transducer and an output port connected to the transmitting transducer for producing at the output port of the second amplifier an oscillatory signal having a frequency response versus ambient temperature characteristic equal to the combination of the first and second frequency response versus ambient temperature characteristics.