BALANCE/UNBALANCE FILTER MODULE AND COMMUNICATION APPARATUS

摘要

A switch (SW) is provided, which includes a first port (P1) that inputs and outputs unbalanced signals in a first frequency band, a second port (P2) that inputs and outputs unbalanced signals in a second frequency band, and a third port (P3) that inputs and outputs unbalanced signals in these two frequency bands. The switch (SW) switches a signal path. An unbalanced I/O port (P4) of a first filter (F1) that passes signals in the first frequency band is connected to the port (P1). A port (P7) of a second filter (F2) that passes signals in the second frequency band is connected to the port (P2) . Individual balanced I/O ports of each of the first and second filters (F1, F2) are connected to first and second branch ports (B1, B2) with substantially the same electrical length. A balance coil (BC) for impedance matching is provided between the first and second branch ports.