Patent ID: 9112473
Filing Date: 2015-08-18
Classification: H03H,H04B

Abstract:
1. A branching circuit comprising: a first filter connected between a first input/output terminal and a third input/output terminal and having a pass band that corresponds to a frequency band of a first communication signal; a second filter connected between a second input/output terminal and the third input/output terminal and having a pass band that corresponds to a frequency band of a second communication signal, the pass band of the first filter and the pass band of the second filter being different from each other; a phase shift circuit connected in series to a terminal of the second filter at a side closer to the second input/output terminal; and an amplitude adjustment circuit connected between a terminal of the second filter at a side closer to the third input/output terminal and a terminal of the phase shift circuit at a side closer to the second input/output terminal in parallel to the second filter and the phase shift circuit; wherein the phase shift circuit is configured to rotate a phase of a fundamental component and/or a predetermined harmonic component of the first communication signal leaking from the second filter to be reversed relative to a phase of the first communication signal having passed through the amplitude adjustment circuit at a junction point between the amplitude adjustment circuit and the phase shift circuit; the amplitude adjustment circuit is configured to execute amplitude adjustment such that an amplitude of the first communication signal output from the amplitude adjustment circuit and an amplitude of the first communication signal output from the phase shift circuit are matched with each other at the junction point between the amplitude adjustment circuit and the phase shift circuit; and the phase shift circuit includes a first phase shift circuit configured to adjust the phase of the fundamental component, and a second phase shift circuit configured to adjust the phase of the predetermined harmonic component, the first phase shift circuit and the second phase shift circuit being connected in series.