Integrated on-chip duplexer for simultaneous wireless transmission
View Patent ↗An electrical balancing network combined with coupled inductors (EBN) replaces a transmit/receive switch was used for isolation for time division duplexing transmission techniques. The EBN allows simultaneous transmit operation, or simultaneous receive operation, of multiple wireless technologies that would otherwise have to be scheduled for transmit or receive in a time division multiplexing manner. The wireless technologies may be WLAN, LTE, Bluetooth or other wireless technologies.
1. A circuit comprising:
a first wireless technology communication port;
a second wireless technology communication port;
an antenna port shared by the first wireless technology communication port and the second wireless technology communication port;
a first inductive connection between the first port and the antenna port;
an electrical balancing network coupled between the first port and the second port, the electrical balancing network configured to implement an impedance matched to the antenna port that splits current to divert a portion of a current flowing through the first inductive connection to instead flow from flowing through the first inductive connection to flow instead through the electrical balancing network; and
a second inductive connection between the second port and the antenna port, the second inductive connection implementing a counterbalance coupling with the first inductive connection that is configured to draw the portion of the current to the antenna.
2. The circuit of claim 1 , further comprising:
a transmit/receive switch coupled to the first port and operable to select between transmission or reception at the first wireless technology communication port.
3. The circuit of claim 1 , further comprising:
a transmit/receive switch coupled to the second port and operable to select between transmission and reception at the second wireless technology communication port.
4. The circuit of claim 1 , further comprising:
a first transmit/receive switch coupled to the first port and operable to select between transmission or reception at the first wireless technology communication port;
a second transmit/receive switch coupled to the second wireless technology communication port and operable to select between transmission and reception at the second wireless technology communication port; and
a control input operable to set the first transmit/receive switch and the second transmit/receive switch for simultaneous transmission by both the first port and the second wireless technology communication port.
5. The circuit of claim 1 , further comprising:
a first transmit/receive switch coupled to the first port and operable to select between transmission and reception for the first wireless technology communication port;
a second transmit/receive switch coupled to the second port and operable to select between transmission and reception for the second wireless technology communication port; and
a control input operable to set the first transmit/receive switch and the second transmit/receive switch for simultaneous reception by both the first wireless technology communication port and the second wireless technology communication port.
6. The circuit of claim 1 , where:
the first and second inductive connections are configured to split a signal received at the antenna to provide, for simultaneous reception:
a first receive signal to the first wireless technology communication port; and
a second receive signal to the second wireless technology communication port.
7. The circuit of claim 1 , further comprising:
a wireless network transmit amplifier and a wireless network receive amplifier in communication with the first wireless technology communication port.
8. The circuit of claim 7 , further comprising:
a near field transmit amplifier and a near field receive amplifier in communication with the second wireless technology communication port.
9. A circuit comprising:
a shared transmit port shared by a first wireless technology and a second wireless technology;
a shared receive port shared by the first wireless technology and the second wireless technology;
an antenna port;
a first inductive connection from the shared transmit port to the antenna port;
an electrical balancing network configured to implement an impedance matched to the antenna port that diverts a portion of a current from flowing through the first inductive connection to flow instead flow through the electrical balancing network;
a second inductive connection between the first inductive connection and the electrical balancing network, the second inductive connection configured to inductively counterbalance the first inductive connection when the portion of the current flows through the second inductive connection to the electrical balancing network; and
a third inductive connection coupled to the first inductive connection and the second inductive connection and the shared receive port.
10. The circuit of claim 9 , where:
the shared receive port comprises a differential receive output.
11. The circuit of claim 9 , further comprising:
a receive amplifier coupled to the shared receive port.
12. The circuit of claim 9 , where:
the first inductive connection and the second inductive connection comprise approximately equal impedance.
13. The circuit of claim 9 , where:
the first inductive connection comprises a first impedance;
the second inductive connection comprises a second impedance; and
the first impedance is set in relation to the second impedance to favor transmission over reception.
14. The circuit of claim 9 , where:
the first inductive connection comprises a first impedance;
the second inductive connection comprises a second impedance; and
the first impedance is set in relation to the second impedance to favor reception over transmission.
15. The circuit of claim 9 , where the second inductive connection is configured to inductively counterbalance the first inductive connection by countering induction by the first inductive connection on the third inductive connection.
16. A device comprising:
a first wireless technology port configured to generate an induction effect;
a second wireless technology port;
an antenna circuit inductively coupled inductively coupled between:
the first wireless technology port; and
the second wireless technology port; and
an electrical balancing network inductively coupled between:
the first wireless technology port; and
the second wireless technology port; and
where the electrical balancing network is configured to facilitate a split of the induction effect between the antenna circuit and the electrical balancing network to redirect, at least in part, the induction effect to drive current through the electrical balancing network rather than drive current within the antenna circuit.
17. The device of claim 16 , further comprising:
first differential transmit/receive switches circuit coupled to the first wireless technology port and operable to select between differential transmission and differential reception for the first wireless technology.
18. The device of claim 17 , further comprising:
second differential transmit/receive switches circuit coupled to the second port and operable to select between differential transmission and differential reception for the second wireless technology.
19. The device of claim 16 , where:
the inductive couplings are configured to generate counterbalancing currents that isolate the first wireless technology port from the second wireless technology.
20. The device of claim 16 where the first transmit and receive port is configured to cause transmission by inducing a current between a ground and an antenna within the antenna circuit.