System and Method for a Radio Frequency Filter

A circuit comprising:

• a filter circuit having a first port, a second port and a third port, the filter circuit comprising
• a first passive filter,
• a second passive filter,
• a first coupler having an input port coupled to the first port, an isolated port coupled to the second port, a first phase shifted port coupled to the first passive filter and a second phase shifted port coupled to the second passive filter, wherein the first coupler comprises a −3 dB hybrid with quadrature output, and
• a combining network having a first input coupled to the first passive filter, a second input coupled to the second passive filter, and an output coupled to the third port, wherein the combining network comprises a power splitter, a first phase shifter coupled between the first passive filter and the power splitter, and a second phase shifter coupled between the second passive filter and the power splitter;
• and
• an amplifier comprising an output coupled to the third port.

A circuit comprising:

• a first filter circuit having a first port configured to be coupled to an antenna, a second port and a third port, the first filter circuit comprising
• a first passive filter,
• a second passive filter,
• a first coupler having an input port coupled to the first port, an isolated port coupled to the second port, a first phase shifted port coupled to the first passive filter and a second phase shifted port coupled to the second passive filter, wherein the first coupler comprises a −3 dB hybrid with quadrature output, and
• a first combining network having a first input coupled to the first passive filter, a second input coupled to the second passive filter, and an output coupled to the third port, wherein the first filter circuit is configured to pass a first frequency band from the first port to the third port using a bandpass function, and is configured to pass a second frequency band and a third frequency band from the first port to the second port, and reject the first frequency band from the first port to the second port, wherein the first frequency band comprises frequencies higher than the first frequency band and the third frequency band comprises frequencies lower than the first frequency band;
• and
• a first LNA comprising an input coupled to the third port;
• a first frequency splitting circuit coupled to the first port of the first filter circuit, the first frequency splitting circuit configured to split the third frequency band from the second frequency band;
• a second LNA having an input coupled to a second frequency band output of the first frequency splitting circuit;
• and
• a third LNA having an input coupled to a third frequency band output of the first frequency splitting circuit.

A circuit comprising:

• a filter circuit having a first port configured to be coupled to an antenna, a second port and a third port, the filter circuit comprising
• a first passive filter,
• a second passive filter,
• a first power amplifier having an output coupled to the first passive filter,
• a second power amplifier having an output coupled to the second passive filter,
• a first coupler having an input port coupled to the first port, an isolated port coupled to the second port, a first phase shifted port coupled to the first passive filter and a second phase shifted port coupled to the second passive filter, wherein the first coupler comprises a −3 dB hybrid with quadrature output, and
• a splitting network having a first output coupled to and input of the first power amplifier, a second output coupled to an input of the second power amplifier, and an input coupled to the third port.

A circuit comprising:

• a first RF front-end of a first band;
• a second RF front-end of the first band;
• a first multi-feed antenna;
• a second multi-feed antenna;
• and
• a first RF switch configured to couple the first RF front-end to a first element of the first multi-feed antenna and coupled the second RF front-end to a first element of the second multi-feed antenna in a first configuration, and configured to couple the first RF front-end to the first element of the second multi-feed antenna and couple the second RF front-end to the first element of the first multi-feed antenna in a second configuration.