Hybrid radio frequency combining system with signal cancellation
View Patent ↗A system and method for reducing intermodulation interference between a transmitter circuit and a receiver circuit includes a first hybrid combiner coupled to a transmit port, a second hybrid combiner coupled to an antenna port, a third hybrid combiner coupled to a receive port, a first three port network coupled to the first hybrid combiner, the second hybrid combiner, and the third hybrid combiner, and a second three port network coupled to the first hybrid combiner, the second hybrid combiner, and the third hybrid combiner. Related apparatus, systems, techniques and articles are also described.
1. A system for reducing intermodulation interference between a transmitter circuit and a receiver circuit, the system comprising:
a first hybrid combiner coupled to a transmit port;
a second hybrid combiner coupled to an antenna port;
a third hybrid combiner coupled to a receive port;
a first three port network coupled to the first hybrid combiner, the second hybrid combiner, and the third hybrid combiner;
a second three port network coupled to the first hybrid combiner, the second hybrid combiner, and the third hybrid combiner;
a first gain block circuit coupled to the first hybrid combiner, the first three port network, and the second three port network; and
a second gain block including circuitry, the second gain block coupled to the third hybrid combiner, the first hybrid combiner, and the second hybrid combiner.
2. The system of claim 1 , further comprising control circuitry configured to receive a first receive output signal and a second receive output signal, the control circuitry configured to phase shift and/or attenuate at least one of the first receive output signal and/or the second receive output signal.
3. The system of claim 2 , wherein the control circuitry includes at least one phase shifter and at least one attenuator.
4. The system of claim 2 , further comprising control logic configured to:
receive a first signal characterizing a transmit signal level at the transmit port;
receive a second signal characterizing a receive signal level at the receive port; and
control the control circuitry to reduce a level of transmit signal at the receive port.
5. The system of claim 2 , further comprising control logic configured to:
receive a first signal characterizing a receive signal level at the receive port;
determine intermodulation signal components of the first signal; and
control the control circuitry to reduce a level of intermodulation signal component at the receive port.
6. The system of claim 2 , further comprising control logic configured to:
receive a first signal characterizing a transmit signal level at the transmit port;
receive a second signal characterizing a receive signal level at the receive port;
determine intermodulation signal components of the second signal; and
control the control circuitry to reduce a level of transmit signal at the receive port and to reduce a level of intermodulation signal component at the receive port.
7. The system of claim 2 , wherein the control circuitry is formed as one or more application specific integrated circuits (ASICs).