A direct digital synthesis system for acoustic wave sensors

Author

Sternhagen, Jason D. ; Mitzner, Kraig ; Berkenpas, Eric ; Karlgaard, Matt ; Wold, Cyle E. ; Galipeau, David W.

Author_Institution

Electr. Eng. Dept., South Dakota State Univ., Brookings, SD, USA

Volume

2

Issue

4

fYear

2002

fDate

8/1/2002 12:00:00 AM

Firstpage

288

Lastpage

293

Abstract

Current designs for acoustic wave sensor system electronics are typically based on surface acoustic wave (SAW) oscillators, phase detectors, or phase-locked loops to measure changes in SAW velocity. The advantage of oscillators is a high resolution frequency output, as compared to phase detection systems which are more stable and can more easily provide amplitude information. Phase-locked loops (PLL) offer advantages of both the oscillator and phase detection systems but have the disadvantages of a fixed frequency range and the need for frequency counting circuitry. The objectives of this work were to study the performance of a direct digital synthesis (DDS) based PLL system with the advantages of a programmable frequency range, elimination of the need for frequency counting circuitry, and tolerance of large SAW sensor insertion losses. The DDS system tested had a resolution of 4 Hz and a range of 80 to 120 MHz in SAW humidity and temperature sensing applications indicating that the DDS based PLL is a practical electronic system for SAW sensors.

Keywords

VHF circuits; direct digital synthesis; humidity sensors; network synthesis; phase locked loops; surface acoustic wave sensors; temperature sensors; 80 to 120 MHz; SAW sensor DDS based PLL system; SAW sensor insertion loss tolerance; SAW velocity change measurement; acoustic wave sensor systems; amplitude information extraction; direct digital synthesis based system; frequency counting circuitry; high resolution frequency output; humidity sensing applications; phase detection systems; phase detector stability; phase-locked loops; programmable frequency range; surface acoustic wave oscillators; temperature sensing applications; Acoustic sensors; Acoustic waves; Circuits; Frequency synthesizers; Oscillators; Phase detection; Phase locked loops; Sensor systems; Surface acoustic waves; Temperature sensors;

fLanguage

English

Journal_Title

Sensors Journal, IEEE

Publisher

ieee

ISSN

1530-437X

Type

jour

DOI

10.1109/JSEN.2002.803744

Filename

1044381