Novel bulk acoustic-wave high-Q resonators and acoustically coupled resonator filters have been fabricated and operated at their fundamental half-wavelength mode in the 200-500-MHz frequency range. These structures are fabricated on thin ZnO/silicon diaphragms with dimensions small enough to be incorporated within integrated circuits. Resonator Q’s near 2600 at the fundamental mode have been obtained and strong inter-resonator acoustic coupling has been achieved yielding filters having insertion loss (untuned) as low as 5.5 dB.

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We have demonstrated a new type of buried-channel acoustic charge transport device in which charge is transported in an (Al,Ga)As/GaAs/(Al,Ga)As heterojunction channel. Traveling-wave potential wells, associated with a surface acoustic wave (SAW) propagating on the 〈100〉 surface of a GaAs crystal, transport electrons at the SAW velocity by means of a large-signal acoustoelectric interaction. Heterojunction acoustic charge transport (HACT) delay lines have been fabricated, and the transport of charge demonstrated. Charge packets with up to 16×106 electrons/cm were measured in a delay 1.4 μs long. The HACT device is much simpler, the transport channel is more reliably produced (by molecular beam epitaxy or metalorganic chemical vapor deposition), and the device has potential for higher dynamic range when compared to the previously developed acoustic charge transport technology. This new device type is useful for the implementation of high-speed monolithic signal processors.

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