Patent ID: 8680943

Claim:
A DCS (Digital Cellular System)/WCDMA (Wideband Code Division Multiple Access) dual frequency multiplexer used to multiplex two signals with different frequencies, comprising: a multiplexer port configured to convey two signals with different frequencies, a first port configured to convey a signal at a first frequency, and a second port configured to convey a signal at a second frequency, wherein the first port is connected with the multiplexer port through a first RF (radio frequency) circuit and a first direct current circuit; wherein the second port is connected with the multiplexer port through a second RF circuit and a second direct current circuit; each RF circuit comprises a band pass filter and the band pass filter in series with capacitors connected to each of two sides of the band pass filter and configured to filter a direct circuit signal from a RF circuit signal; the two band pass filters are coupled with the multiplexer port via a common capacitor to convey the signal to/from the multiplexer port; each direct current circuit comprises a low pass filter and a discharging tube connected to the low pass filter electrically; and the two direct current circuits are electrically connected to the multiplexer port through the low pass filters wherein the filtered signals are combined at, and outputted from, the multiplexer port; wherein the multiplexer also comprises a box including a base body, a circuit board and a cover body; the two band pass filters are disposed in the base body and separated from each other by a metal plate; the multiplexer port, first and second ports are positioned on a lateral side of the base body; the capacitors are contained in corresponding band pass filters; a plurality of support members are disposed on top portion of the base body; the low pass filters are supported on the support members; the discharging tube and switch are secured on the circuit board; the cover body is clamped together with the base body.