Transmission/reception separation circuit, transceiver, and wireless communications device
The present disclosure discloses example transmission/reception separation circuits and transceiver. One example transmission/reception separation circuit includes a transmission amplification circuit, an impedance adjustment circuit, and a reception amplification circuit. An output end of the transmission amplification circuit is connected to the impedance adjustment circuit. The impedance adjustment circuit is further connected to an input end of the reception amplification circuit. The second end of the impedance adjustment circuit and the input end of the reception amplification circuit are further configured to be connected to an antenna. The transmission amplification circuit amplifies a first signal to be transmitted. The reception amplification circuit amplifies a second signal received. When the antenna transmits the amplified first signal, a first impedance is in a high impedance state. The impedance adjustment circuit adjusts a second impedance to a high impedance state when the antenna receives the second signal.
1. A transmission/reception separation circuit, comprising: a transmission amplification circuit, an impedance adjustment circuit, and a reception amplification circuit, wherein:
an output end of the transmission amplification circuit is connected to a first end of the impedance adjustment circuit, a second end of the impedance adjustment circuit is connected to an input end of the reception amplification circuit, and the second end of the impedance adjustment circuit and the input end of the reception amplification circuit are further configured to be connected to an antenna;
the transmission amplification circuit is configured to amplify a first signal to be transmitted by using the antenna;
the reception amplification circuit is configured to amplify a second signal received by using the antenna, wherein when the antenna transmits the amplified first signal, a first impedance is in a high impedance state, and the first impedance is an impedance seen from the input end of the reception amplification circuit;
the reception amplification circuit comprises a reception power amplifier and a reception switch, an input end of the reception power amplifier is connected to a first end of the reception switch, a second end of the reception switch is connected to the second end of the impedance adjustment circuit, and the second end of the reception switch is further configured to be connected to the antenna; and
the impedance adjustment circuit is configured to adjust a second impedance to a high impedance state when the antenna receives the second signal, wherein the second impedance is an impedance seen from the second end of the impedance adjustment circuit.
2. The transmission/reception separation circuit according to claim 1 , wherein the impedance adjustment circuit is a circuit formed through hybrid connection of a capacitor and an inductor, or a microstrip circuit.
3. The transmission/reception separation circuit according to claim 1 , wherein:
the transmission amplification circuit comprises a first switch and a first power amplifier, the first switch is separately connected to a power supply end of the first power amplifier and a power supply of the first power amplifier, and an output end of the first power amplifier is connected to the first end of the impedance adjustment circuit;
when the antenna transmits the amplified first signal, the first switch is in a closed state; and
when the antenna receives the second signal, the first switch is in an open state.
4. The transmission/reception separation circuit according to claim 1 , wherein:
the transmission amplification circuit comprises a first switch, a balanced combination amplification circuit, and a second switch, the first switch is separately connected to a power supply end of a power amplifier in the balanced combination amplification circuit and a power supply of the power amplifier in the balanced combination amplification circuit, an absorption load at an isolation end of the balanced combination amplification circuit is connected to the isolation end of the balanced combination amplification circuit by using the second switch, and an output end of the balanced combination amplification circuit is connected to the first end of the impedance adjustment circuit;
when the antenna transmits the amplified first signal, the first switch and the second switch are in a closed state; and
when the antenna receives the second signal, the first switch and the second switch are in an open state.
5. The transmission/reception separation circuit according to claim 4 , wherein the balanced combination amplification circuit is a 3 dB bridge balanced combination amplification circuit, the isolation end of the 3 dB bridge balanced combination amplification circuit is connected to the absorption load by using the second switch, and the output end of the 3 dB bridge balanced combination amplification circuit is connected to the first end of the impedance adjustment circuit.
6. The transmission/reception separation circuit according to claim 4 , wherein the balanced combination amplification circuit is a Wilkinson balanced combination amplification circuit, the transmission amplification circuit comprises two second switches, two ends of the absorption load at the isolation end of the Wilkinson balanced combination amplification circuit are separately connected in parallel at the isolation end of the Wilkinson balanced combination amplification circuit by using the two second switches, and the output end of the Wilkinson balanced combination amplification circuit is connected to the first end of the impedance adjustment circuit.
7. The transmission/reception separation circuit according to claim 1 , wherein:
when the antenna transmits the amplified first signal, the reception switch is in an open state; and
when the antenna receives the second signal, the reception switch is in a closed state.
8. A transceiver, applied to a wireless communications device, comprising a transmission/reception separation circuit, wherein the transmission/reception separation circuit comprises:
a transmission amplification circuit, an impedance adjustment circuit, and a reception amplification circuit, wherein:
an output end of the transmission amplification circuit is connected to a first end of the impedance adjustment circuit, a second end of the impedance adjustment circuit is connected to an input end of the reception amplification circuit, and the second end of the impedance adjustment circuit and the input end of the reception amplification circuit are further configured to be connected to an antenna;
the transmission amplification circuit is configured to amplify a first signal to be transmitted by using the antenna;
the reception amplification circuit is configured to amplify a second signal received by using the antenna, wherein when the antenna transmits the amplified first signal, a first impedance is in a high impedance state, and the first impedance is an impedance seen from the input end of the reception amplification circuit;
the reception amplification circuit comprises a reception power amplifier and a reception switch, an input end of the reception power amplifier is connected to a first end of the reception switch, a second end of the reception switch is connected to the second end of the impedance adjustment circuit, and the second end of the reception switch is further configured to be connected to the antenna; and
the impedance adjustment circuit is configured to adjust a second impedance to a high impedance state when the antenna receives the second signal, wherein the second impedance is an impedance seen from the second end of the impedance adjustment circuit.
9. The transceiver according to claim 8 , wherein the impedance adjustment circuit is a circuit formed through hybrid connection of a capacitor and an inductor, or a microstrip circuit.
10. The transceiver according to claim 8 , wherein:
the transmission amplification circuit comprises a first switch and a first power amplifier, the first switch is separately connected to a power supply end of the first power amplifier and a power supply of the first power amplifier, and an output end of the first power amplifier is connected to the first end of the impedance adjustment circuit;
when the antenna transmits the amplified first signal, the first switch is in a closed state; and
when the antenna receives the second signal, the first switch is in an open state.
11. The transceiver according to claim 8 , wherein:
the transmission amplification circuit comprises a first switch, a balanced combination amplification circuit, and a second switch, the first switch is separately connected to a power supply end of a power amplifier in the balanced combination amplification circuit and a power supply of the power amplifier in the balanced combination amplification circuit, an absorption load at an isolation end of the balanced combination amplification circuit is connected to the isolation end of the balanced combination amplification circuit by using the second switch, and an output end of the balanced combination amplification circuit is connected to the first end of the impedance adjustment circuit;
when the antenna transmits the amplified first signal, the first switch and the second switch are in a closed state; and
when the antenna receives the second signal, the first switch and the second switch are in an open state.
12. The transceiver according to claim 11 , wherein the balanced combination amplification circuit is a 3 dB bridge balanced combination amplification circuit, the isolation end of the 3 dB bridge balanced combination amplification circuit is connected to the absorption load by using the second switch, and the output end of the 3 dB bridge balanced combination amplification circuit is connected to the first end of the impedance adjustment circuit.
13. The transceiver according to claim 11 , wherein the balanced combination amplification circuit is a Wilkinson balanced combination amplification circuit, the transmission amplification circuit comprises two second switches, two ends of the absorption load at the isolation end of the Wilkinson balanced combination amplification circuit are separately connected in parallel at the isolation end of the Wilkinson balanced combination amplification circuit by using the two second switches, and the output end of the Wilkinson balanced combination amplification circuit is connected to the first end of the impedance adjustment circuit.