Implementation of an RCPF and its Measurement Circuitry for the Method Based on Superposition

An RC polyphase filter (RCPF) is a passive complex filter consisting of resistors and capacitors. In measurement of its frequency response, it is required to apply sinusoidal waves whose amplitudes are the same as the others and whose phase leads are 90 or −90 degrees. However, it is difficult to realize them. This problem can be solved by using a technique based on the principle of superposition. In this paper, an RCPF under test and its peripheral circuit required for measurement are implemented on an integrated circuit using the $0.6\mu \mathrm{m}$ CMOS process. Its experimental results are shown.