Duplexer, multiplexer and multiband filter

A dual-port-matched band pass filter (DPMBPF), comprising:

• a filter main part, the filter main part configured to filter an RF signal;
• a first port-matching part coupled to and in signal communication with the filter main part, the first port-matching part including a first port, the first port configured to be connected to ports of one or more other DPMBPFs, the first port configured to transmit or receive the RF signal, the first port-matching part configured to provide impedance matching through the first port to match the ports of the connected other DPMBPFs;
• and
• a second port-matching part coupled to and in signal communication with the filter main part, the second port-matching part including a second port, the second port configured to be connected to another ports of the other DPMBPFs, the second port configured to transmit or receive the RF signal, the second port-matching part configured to provide impedance matching through the second port to match the another ports of the connected other DPMBPFs.

A dual-band filter comprising:

• a first dual-port-matched band pass filter (DPMBPF);
• and
• a second DPMBPF,
• each of the first and second DPMBPF having
• a filter main part configured to filter RF signals,
• a first port-matching part coupled in signal communication with the filter main part, the first port-matching part having a first port, the first port configured to be connected to another first port of the other DPMBPF where one of the two first ports being configured as a common input/output port, the first port-matching part configured to provide impedance matching through the first port to match the first port of the connected other DPMBPF;
• and
• a second port-matching part coupled in signal communication with the filter main part, the second port-matching part having a second port, the second port configured to be connected to another second port of the two DPMBPFs, one of the two second ports being configured as another input/output common port, the second port-matching part configured to provide impedance matching through the second port to match the second port of the connected other DPMBPF.

A multiband filter comprising:

• a plurality dual-port-matched band pass filters (DPMBPFs);
• each of the plurality of DPMBPFs having
• a filter main part configured to filter RF signals,
• a first port-matching part coupled in signal communication with the filter main part, the first port-matching part having a first port, the first port configured to be connected to another first ports of at least one of the remaining plurality of DPMBPFs, the first port-matching part configured to provide impedance matching through the first port to match the first port of the connected DPMBPFs, one of the first ports of the plurality of DPMBPFs being configured as a common input/output port, and
• a second port-matching part coupled in signal communication with the filter main part, the second port-matching part having a second port, the second port configured to be connected to the second port of at least one of the remaining DPMBPFs, one of the second ports being configured as another input/output common port, the second port-matching part configured to provide impedance matching through the second port to match the second port of the connected other DPMBPFs.