FILTER CIRCUIT, CLASS-F POWER AMPLIFIER, INVERSE CLASS-F POWER AMPLIFIER

摘要

The present invention is a filter circuit that filters an input signal for a given frequency bandwidth, and is provided with a 1/4 wavelength open stub, the length of which is one quarter of the wavelength of the maximum frequency of the given frequency bandwidth, and a first phase adjustment unit having negative group delay characteristics and connected to an input terminal of the 1/4 wavelength open stub.