Frequency hopping due to acousto-electric interaction in ZnO based surface acoustic wave oscillator

Abstract

A 36 MHz surface acoustic wave delay line based oscillator has been used to study the effect of acousto-electric interaction due to photo generated charge carriers in rf sputtered ZnO film under UV illumination (λ = 365 nm, 20–100 μW/cm2). Design aspects for developing a delay line based SAW oscillator are specified. The observed linear downshift in frequency (2.2 to 19.0 kHz) with varying UV intensity (20–100 μW/cm2) is related to the fractional velocity change due to acousto-electric interaction. UV illumination level of 100 μW/cm2 leads to a characteristic frequency hopping behavior arising due to a change in the oscillation criteria, and is attributed to the complex interplay between the increased attenuation and velocity shift.

Tunable surface acoustic wave device using semiconducting MgZnO and piezoelectric NiZnO dual-layer structure on glass

“…SAW technology has also been implemented on biomolecule manipulations [6][7][8][9], optical signal modulation [10][11][12][13], and functional thin film fabrication [14]. Recently, the development of tunable SAW as an important type of tunable RF devices finds many promising niche applications in the optical system [12], frequency-hopping spreading spectrum [15], programmable RFID tag [16], and adaptive wireless communication [17].…”

Visible-light photoresponse of AlN-based film bulk acoustic wave resonator

“…Several authors have reported the effect of ultraviolet radiation on ZnO-based FBARs and ZnO, GaN, and AlGaN-based surface acoustic wave devices. 5,[7][8][9][10] It is noteworthy that different combinations of materials and light source wavelengths were used in those studies, suggesting that indirect-bandgap photoresponses are responsible for the resonant frequency shift observed. Those experimental results indicate that it might be possible to develop visiblelight photosensors based on the fabricated devices.…”