Bounds on permittivity calculations using the TE/sub 01/spl delta// dielectric resonator
The use of both mode-matching and Rayleigh-Ritz numerical techniques for complex permittivity calculations using a TE/sub 01/spl delta// mode dielectric resonator allows the determination of lower and upper bounds of the permittivity. The maximum difference of the relative permittivity obtained from the two techniques does not exceed 0.125% for a cavity-to-sample volume ratio from 1 to 64 and relative permittivity values in the range of 1 to 100. These results were obtained by employing 126 basis functions with the Rayleigh-Ritz technique and 10 basis functions with the mode-matching method. It is possible to increase the computational accuracy of the calculations by increasing the number of basis functions.
In this study, the tin oxide membrane, fabricated by the sol–gel technology, was used as the pH-sensing layer of the extended gate H+-ion sensitive field effect transistor (EGFET) device. The sensing membrane was deposited on the silicon substrate. The cost of fabricating the EGFET device by the sol–gel technology is lower than by the other methods. The sensitivity of the sol–gel prepared tin oxide separative structure EGFET device is about 57.63 mV/pH in the range of pH1 to pH9. The readout circuit of the tin oxide EGFET was developed by the source follower.