The Cl2-sensitive heteropolysiloxanes(HPS) film was formed on the interdigital capacitor based on silicon dioxide by means of sol-gel process and spin-on technique.Measurements of interdigital capacitance were perform...The Cl2-sensitive heteropolysiloxanes(HPS) film was formed on the interdigital capacitor based on silicon dioxide by means of sol-gel process and spin-on technique.Measurements of interdigital capacitance were performed at room temperature for frequencies 100 Hz,1 kHz and 10 kHz.It is shown that there is a linear relationship between the capacitance and the concentration of chlorine gas.Influences of the measurement frequency and film thickness of silicate on the sensitivity of the sensor to C12 gas were discussed.And organically modified N,N-diethylaminopropyl-trimethoxysilane (APMS) had a much higher sensitivity.展开更多
With the principles of microwave circuits and semiconductor device physics,three kinds of microwave power device test circuits are designed and simulated,whose properties are evaluated by a parameter network analyzer ...With the principles of microwave circuits and semiconductor device physics,three kinds of microwave power device test circuits are designed and simulated,whose properties are evaluated by a parameter network analyzer within the frequency range from 3 to 8GHz.The simulated results verify that the test circuit with stepped-impedance filter bias network has a larger bandwidth than that with the radial stub.A microstrip interdigital capacitor is used in the third test circuit to replace the DC block,however,which does not show its advantage during the test frequency band.Based on the simulated results,the stepped-impedance filter test circuit can be used to evaluate microwave power devices in the whole C band,namely from 4 to 8GHz.展开更多
文摘The Cl2-sensitive heteropolysiloxanes(HPS) film was formed on the interdigital capacitor based on silicon dioxide by means of sol-gel process and spin-on technique.Measurements of interdigital capacitance were performed at room temperature for frequencies 100 Hz,1 kHz and 10 kHz.It is shown that there is a linear relationship between the capacitance and the concentration of chlorine gas.Influences of the measurement frequency and film thickness of silicate on the sensitivity of the sensor to C12 gas were discussed.And organically modified N,N-diethylaminopropyl-trimethoxysilane (APMS) had a much higher sensitivity.
文摘With the principles of microwave circuits and semiconductor device physics,three kinds of microwave power device test circuits are designed and simulated,whose properties are evaluated by a parameter network analyzer within the frequency range from 3 to 8GHz.The simulated results verify that the test circuit with stepped-impedance filter bias network has a larger bandwidth than that with the radial stub.A microstrip interdigital capacitor is used in the third test circuit to replace the DC block,however,which does not show its advantage during the test frequency band.Based on the simulated results,the stepped-impedance filter test circuit can be used to evaluate microwave power devices in the whole C band,namely from 4 to 8GHz.
