Mohammad Neshat et al 2010 Meas. Sci. Technol. 21 015202 doi:10.1088/0957-0233/21/1/015202
Mohammad Neshat1, Huanyu Chen1, Suren Gigoyan2, Daryoosh Saeedkia3 and Safieddin Safavi-Naeini1
Show affiliationsWe propose, for the first time, the application of whispering gallery mode (WGM) perturbation technique in dielectric analysis of disk shape pharmaceutical tablets. Based on WGM resonance, a low-cost high sensitivity sensor in milllimeter-wave frequency range is presented. A comprehensive sensitivity analysis was performed to show that a change in the order of 10−4 in the sample permittivity can be detected by the proposed sensor. The results of various experiments carried out on drug tablets are reported to demonstrate the potential multifunctional capabilities of the sensor in moisture sensing, counterfeit drug detection and contamination screening. Analytically, two sample placement configurations, i.e. a tablet placed on top of a dielectric disk resonator and inside a dielectric ring resonator, have been studied to predict the resonance frequency and Q-factor of the combined sample-resonator structure. The accuracy of the analytical model was tested against full-wave simulations and experimental data.
87.80.-y Biophysical techniques (research methods)
07.07.Df Sensors (chemical, optical, electrical, movement, gas, etc.); remote sensing
89.20.Bb Industrial and technological research and development
85.50.-n Dielectric, ferroelectric, and piezoelectric devices
Issue 1 (January 2010)
Received 15 May 2009, in final form 11 September 2009
Published 23 November 2009
Mohammad Neshat et al 2010 Meas. Sci. Technol. 21 015202
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