High frequency performance 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) are required. We have tested the performance of several MLC designs to find out the effect of the ESR and ESL. We have developed an ultra small capacitor that has good performance for high frequency and high speed digital circuits. In order to measure the high frequency performance accurately, we have developed a test fixture using a microstrip design. The fixture has a return loss of greater than 30 dB and an insertion loss less than 0.5 dB. The MLC is mounted on the microstrip fixture and the return loss and insertion loss are measured. A network analyzer is used to compensate for the fixture to obtain good data up to 15 GHz.