Patent attributes
A multi-layer band-pass filter comprises an unbalanced input, two balanced outputs, and a band-pass filter section provided between the unbalanced input and the two balanced outputs. The band-pass filter section incorporates a plurality of resonators each of which is made up of a TEM line. The band-pass filter further comprises a multi-layer substrate used for integrating the resonators. The band-pass filter section incorporates, as the resonators, an input resonator, and a half-wave resonator for balanced output that is made up of a half-wave resonator having open-circuited ends. The unbalanced input is connected to the input resonator through a capacitor. Each of the balanced outputs is connected to the half-wave resonator through a capacitor.