High frequency measurement of multilayer ceramic capacitors

Abstract

The monolithic ceramic capacitor (MLC) is small and has good high frequency performance. It is used in various high frequency circuits for impedance matching, DC block, filter and bypass functions. For the best performance in these applications, low equivalent series resistance (ESR) and equivalent series inductance (ESL) is required. We have developed the testing method to compare the performance of different MLC designs to find out the effect on the ESR and ESL. In order to measure the high frequency performance accurately, we have developed a test fixture using the microstrip design. The fixture has a return loss of greater than 30 dB and the insertion loss is less than 0.5 dB. The MLC is mounted on the microstrip fixture and the return loss (RL) and the insertion loss (IL) is measured. A network analyzer is used to compensate for the fixture to obtain good data up to 15 GHz. Using this method, we compare two designs for microwave power applications and two designs for high speed digital applications. We have developed the ultra small capacitor that has good performance in high speed digital circuits.