US Patent 7324493 3-frequency branching circuit, branching circuit and radio communication equipment

A 3-frequency branching circuit in the past could not be used for a system wherein a TDMA method such as GSM and DCS and a W-CDMA method such as UMTS are mixed. The 3-frequency branching circuit equipped with branching means having first and second internal terminals, an antenna terminal of connecting to an antenna, a low-pass filter connected between the first internal terminal and the antenna terminal, and a high-pass filter connected between the second internal terminal and the antenna terminal, a switching circuit of switching between GSM TX and GSM RX, a switching circuit of switching between DCS TX, DCS RX and a third internal terminal, and a duplexer connected to the third internal terminal.