Patent ID: 7676252

Claim:
A filter circuit comprising: an input terminal configured to input an input signal; first to ith blocks which respectively have first to ith resonators as transmission lines having corresponding first to ith resonance frequencies (first resonance frequency<second resonance frequency < . . . <ith resonance frequency); a power divider configured to distribute the input signal to the first to ith blocks; a power combiner configured to combine signals which have passed through the first to ith blocks to obtain a combined signal; and an output terminal configured to output the combined signal, wherein a jth block (j is an integer between 1 and i−1) includes a phase adjustment unit which provides a signal of the jth block with a phase difference within a range of {(180±30)+(360×n)} degrees (n is an integer equal to or greater than 0) from a signal of a (j+1)th block, and a resonator having a large amount of group delay has a greater line width than a resonator having a small amount of group delay, the resonator having a large amount of group delay being any one of the first to ith resonators and the resonator having a small amount of group delay being different from any one of the first to ith resonators.