The invention discloses an electromagnetic
hybrid coupling-based micro-strip
duplexer, which comprises a double-faced
copper-plated micro-strip board, wherein two filters with controllable
passband frequency and bandwidth, a first port feeder, a second port feeder, a T-joint, a first port, a second port and a third port are formed on one surface of the double-faced
copper-plated micro-strip board, and a
copper-plated grounding plate is arranged on the other surface of the double-faced copper-plated micro-strip board; the two filters are respectively formed by three quarter-wave micro-strip resonators coupled with one another, a connection part at one end of the three resonators is provided with a grounding hole, and
electric coupling is generated between every adjacent resonators in each filter. According to the
duplexer,
electric coupling is introduced on the basis of the original magnetic
coupling, so that the bandwidth of the
duplexer can be changed freely by adjusting the strength of the magnetic
coupling and the
electric coupling, and the improved filters can generate a plurality of transmission zero points near the upper and lower
cut-off frequencies, so that
mutual influence between the two filters can be reduced through adjusting the positions of the zero points.