Duplexer architecture using 90 degree hybrid coupler based balancing conditions
An electronic device may include isolation circuitry coupled between a transmitter, a receiver, and one or more antennas. The isolation circuitry may include a 90 degree hybrid coupler configured receive a transmission (TX) signal from the transmitter, split the TX signal into a first portion and a second portion, and phase-shift a portion such that the portions are +90 degrees out-of-phase. The isolation circuitry may include phase shifters that phase-shift the portions such that the portions are in-phase prior to propagating to the antenna. The phase shifters may receive a first portion and a second portion of a receiver (RX) signal from splitter circuitry. The phase shifters may phase-shift the portions such that the portions are out-of-phase by −90 degrees. The 90 degree hybrid coupler may phase-shift the first portion and/or the second portion such that the portions are in-phase and constructively combine prior to propagating to the receiver.
1. A communication device, comprising:
one or more antennas;
a transmit circuit;
a receive circuit;
splitter circuitry coupled to the one or more antennas, the splitter circuitry configured to split a signal received at the one or more antennas into a first portion and a second portion;
at least one phase shifter coupled to the splitter circuitry, the at least one phase shifter configured to shift the first portion of the signal; and
a 90 degree hybrid coupler comprising a plurality of ports, the 90 degree hybrid coupler coupled to
the at least one phase shifter via a first port of the plurality of ports,
the transmit circuit via a second port of the plurality of ports, and
the receive circuit via a third port of the plurality of ports,
the 90 degree hybrid coupler configured to shift the first portion of the signal and constructively combine the first portion of the signal and the second portion of the signal.
2. The communication device of claim 1 , comprising
a first impedance tuner coupled to the 90 degree hybrid coupler via the first port, and
a second impedance tuner coupled to the 90 degree hybrid coupler via a fourth port of the plurality of ports, the first impedance tuner configured to adjust a first input impedance of the first port and the second impedance tuner configured to adjust a second input impedance of the fourth port to balance the first input impedance and the second input impedance of the 90 degree hybrid coupler.
3. The communication device of claim 1 , comprising an antenna tuner coupled to the splitter circuitry, the splitter circuitry comprising a 180 degree isolator, the antenna tuner configured to match an impedance of the one or more antennas.
4. The communication device of claim 3 , wherein the 180 degree isolator is configured to shift the second portion of the signal to destructively combine the second portion of the signal with the first portion of the signal to reduce signal transmission to the antenna tuner.
5. The communication device of claim 1 , comprising an antenna tuner coupled to the splitter circuitry, the splitter circuitry comprising a second 90 degree hybrid coupler, the antenna tuner configured to match an impedance of the one or more antennas.
6. The communication device of claim 5 , wherein the second 90 degree hybrid coupler is configured to split the signal received by the one or more antennas into the first portion of the signal and the second portion of the signal and shift the first portion of the signal.
7. The communication device of claim 1 , wherein the 90 degree hybrid coupler is configured to shift the second portion of the signal to destructively combine the second portion of the signal with the first portion of the signal to reduce signal transmission to the transmit circuit.
8. The communication device of claim 1 , wherein the at least one phase shifter comprises a transition frequency that is set based on a transmission frequency associated with the transmit circuit and a receive frequency associated with the receive circuit.
9. A communication device comprising
one or more antennas;
a transmit circuit;
a receive circuit; and
isolation circuitry coupled to the one or more antennas, the transmit circuit, and the receive circuit, the isolation circuitry comprising a 90 degree hybrid coupler and at least one phase shifter, the 90 degree hybrid coupler coupled to
the at least one phase shifter via a first port of a plurality of ports of the 90 degree hybrid coupler,
the transmit circuit via a second port of the plurality of ports, and
the receive circuit via a third port of the plurality of ports,
the 90 degree hybrid coupler configured to receive a signal from the transmit circuit via the first port, split the signal into a first portion and a second portion, phase-shift the first portion of the signal, and the at least one phase shifter configured to phase-shift the second portion of the signal such that the first portion and the second portion are in phase.
10. The communication device of claim 9 , wherein the isolation circuitry comprises at least one impedance tuner coupled to the 90 degree hybrid coupler via at least one port of the plurality of ports, the at least one impedance tuner configured to balance an input impedance of the 90 degree hybrid coupler.
11. The communication device of claim 9 , comprising combiner circuitry coupled to the one or more antennas and the at least one phase shifter, the combiner circuitry comprising a second 90 degree hybrid coupler configured to phase-shift the first portion and constructively combine the first portion of the signal and the second portion of the signal prior to propagating the signal to the one or more antennas.
12. The communication device of claim 11 , wherein the combiner circuitry comprises an antenna tuner coupled to the second 90 degree hybrid coupler opposite the one or more antennas, the antenna tuner configured to match an impedance of the one or more antennas.
13. The communication device of claim 11 , wherein the combiner circuitry comprises a 180 degree isolator configured to phase-shift the second portion of the signal to destructively combine the second portion of the signal with the first portion of the signal.
14. Isolation circuitry comprising:
at least one phase shifter coupled to one or more antennas and configured to phase-shift a first portion of a receive signal from the one or more antennas, a second portion of the receive signal, or both; and
a 90 degree hybrid coupler comprising
a first port coupled to the at least one phase shifter,
a second port coupled to a transmit circuit, and
a third port coupled to a receive circuit, the 90 degree hybrid coupler configured to combine the first portion and the second portion of the receive signal and the second portion of the receive signal, and split a transmission signal from the transmit circuit.
15. The isolation circuitry of claim 14 , wherein the 90 degree hybrid coupler is configured to split the transmission signal into a first portion and a second portion and phase-shift the first portion of the transmission signal.
16. The isolation circuitry of claim 15 , comprising combiner circuitry coupled to the at least one phase shifter, the at least one phase shifter configured to phase-shift the first portion of the transmission signal, the second portion of the transmission signal, or both, such that first portion and the second portion are in phase.
17. The isolation circuitry of claim 16 , wherein the combiner circuitry is configured to constructively combine the first portion and the second portion.
18. The isolation circuitry of claim 14 , wherein the 90 degree hybrid coupler is configured to phase-shift the first portion of the receive signal to constructively combine the first portion of the receive signal and the second portion of the receive signal prior to propagating the receive signal to the receive circuit.
19. The communication device of claim 11 , wherein the combiner circuitry is configured to receive a receive signal from the one or more antennas and split the receive signal into a first portion of the receive signal and a second portion of the receive signal, and wherein the 90 degree hybrid coupler is configured to phase-shift the second portion of the receive signal to destructively combine the second portion of the receive signal with the first portion of the receive signal to reduce signal transmission to the transmit circuit.
20. The isolation circuitry of claim 14 , wherein the 90 degree hybrid coupler is configured to destructively combine the second portion of the receive signal with the first portion of the receive signal to reduce signal transmission to the transmit circuit.