FEASIBILITY OF AN ELECTRO-ACOUSTIC TRANSCEIVER (FEAT).
Final rept. May 66-Aug 68,
MOTOROLA INC SCOTTSDALE ARIZ GOVERNMENT ELECTRONICS DIV
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Theoretical and experimental work was directed toward the development of unique functional electronic elements employing acoustic and electro-acoustic phenomena in piezoelectric semiconducting solids. Surface barrier and diffusion layer transducer regions were formed in semiconducting ZnO. Shear and longitudinal mode diffusion layer transducers were developed with conversion losses of 5 dB in the VHF region. Thin film CdS transducers were developed for efficient excitation in quartz, zinc oxide and cadmium sulfide. The semiconductor and acoustic properties of vapor phase and hydrothermal ZnO were evaluated. Acoustoelectric effects were observed in ZnO and an evaluation made of the strength of the electron-phonon interaction. Lattice mode amplification in ZnO was observed but no coherent amplification or oscillation was achieved. Electron mirror microscope measurements indicated the presence of severe resistivity gradients in the ZnO crystals. The interaction of acoustic waves in quartz, ZnO and CdS was investigated as a means of performing frequency conversion and duplexing functions. Transceiver CdS ultrasonic traveling wave amplifiers were fabricated at 60 and 200 MHz with bilateral gain of 20 dB. Author
- Electrical and Electronic Equipment