Transmit and receive switch with transformer
In examples, an electronic device includes an antenna and a transmitter line. The transmitter line includes a double-tuned transformer having first and second windings, the first winding having first and second ends, the second winding having third and fourth ends, and the third end coupled to the antenna. The transmitter line includes a first capacitor coupled between the first and second ends. The transmitter line also includes a second capacitor coupled between the third and fourth ends, and a switch coupled between the first end and a reference terminal.
1 . An electronic device, comprising:
a first winding having first and second ends and coupled to a first terminal;
a second winding having third and fourth ends and coupled to a second terminal;
a first capacitor coupled between the first and second ends;
a second capacitor coupled between the fourth and third ends; and
a switch, wherein the switch and the first capacitor are coupled in parallel between the first and second ends, and the switch is configurable to shunt at least the first capacitor.
2 . The electronic device of claim 1 , wherein, in a first mode, the first and second windings are configurable as an impedance inverter and the switch is closed.
3 . The electronic device of claim 2 , wherein the impedance inverter is configurable to provide an impedance based on an impedance of the closed switch.
4 . The electronic device of claim 1 , wherein, in a second mode, the first and second windings are configurable as a bandpass filter.
5 . The electronic device of claim 4 , wherein a frequency band of the bandpass filter is based on capacitances of the first and second capacitors, inductances of the first and second windings, and a coupling coefficient between the first and second windings.
6 . The electronic device of claim 1 , wherein the switch is a first switch, and the electronic device further comprises a second switch coupled between the third and fourth ends, and a third switch coupled between the third or fourth end and a third terminal.
7 . The electronic device of claim 6 , wherein, in a first mode, the third switch is closed and the second switch is open.
8 . The electronic device of claim 7 , wherein, in a second mode, the third switch is open and the second switch is closed.
9 . The electronic device of claim 1 , wherein the first and second windings are configurable to resonate at a frequency based on capacitances of the first and second capacitors.
10 . The electronic device of claim 1 , wherein the switch includes multiple transistors coupled in a series configuration.
11 . The electronic device of claim 1 , further comprising a power amplifier coupled to the first terminal and an antenna coupled to the second terminal.
12 . An electronic device, comprising:
a first winding having first and second ends and coupled to a first terminal;
a second winding having third and fourth ends and coupled to a second terminal;
a first capacitor coupled between the first and second ends;
a second capacitor coupled between the fourth and third ends; and
a switch coupled between the first and second ends, the switch configurable to open in a transmit mode and close in a receive mode.
13 . The electronic device of claim 12 , wherein the switch is a first switch, and the electronic device further comprises:
a second switch coupled between the third and fourth ends; and
a third switch coupled between the third or fourth end and a third terminal.
14 . The electronic device of claim 13 , wherein, in the receive mode, the third switch is closed and the second switch is open.
15 . The electronic device of claim 13 , wherein, in the transmit mode, the third switch is open and the second switch is closed.
16 . The electronic device of claim 12 , wherein the first and second windings are configurable to resonate at a frequency based on capacitances of the first and second capacitors.
17 . An electronic device, comprising:
a first winding having first and second ends and coupled to a first terminal;
a second winding having third and fourth ends and coupled to an antenna terminal;
a first capacitor coupled between the first and second ends;
a second capacitor coupled between the fourth and third ends;
a first switch coupled between the first and second ends;
a second switch coupled between the third and fourth ends; and
a third switch coupled between a second terminal and the third or fourth end.
18 . The electronic device of claim 17 , further comprising a transmit circuit and a receive circuit, the transmit circuit coupled to one of the first or second terminals, and the receive circuit coupled to the other one of the first or second terminals.
19 . The electronic device of claim 17 , wherein, in a transmit mode, the first switch is open, the second switch is closed.
20 . The electronic device of claim 17 , wherein, in a receive mode, the first switch is closed, the second switch is open.
21 . The electronic device of claim 17 , wherein the third switch is closed in a transmit mode, and the third switch is open in a receive mode.
22 . The electronic device of claim 17 , wherein the third switch is open in a transmit mode, and the third switch is closed in a receive mode.
23 . The electronic device of claim 17 , further comprising a controller coupled to the first and second switches and the third switch.
24 . The electronic device of claim 17 , further comprising an antenna coupled to the second terminal and a transceiver coupled to the first terminal.
25 . The electronic device of claim 12 , further comprising a transmit circuit or a receive circuit coupled to the first terminal, and an antenna coupled to the second terminal.
26 . The electronic device of claim 13 , further comprising a transmit circuit or a receive circuit coupled to the third terminal, and an antenna coupled to the second terminal.