| 摘要 |
An electrically controlled surface acoustic wave (SAW) delay unit includes a piezoelectric and semiconductive substrate having a segmented rectifying contact disposed on the surface of an interaction region between launching and detecting transducers, with a controllable voltage applied to the rectifying contact, thereby to vary the concentration of carriers in the semiconductive material, so as to commensurately alter the velocity of surface acoustic waves in the module. The segmented contact provides significant increase in the achievable variation in velocity, and therefore in phase as well. An oscillator configuration includes such a module with an amplifier and other circuit elements formed integrally therewith in a monolithic fashion. Exemplary embodiments include depleting the carrier concentration of semiconductive material, both piezoelectric material and nonpiezoelectric material having a piezoelectric surface layer thereon, as well as enhancement of carrier concentration of semiconductive material at the interface with a piezoelectric surface layer thereon. Various adjunctive design and fabrication techniques are also disclosed.
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