US 8,412,261 B2 · Coupling apparatus for dividing receiving and transmitting signals and control method thereof

Abstract

The present invention is directed to reducing leakage of a transmitting signal to a receiving unit in a wireless communication system with a transmitting unit and the receiving unit sharing an antenna. A coupling apparatus for dividing a radio frequency (RF) transmitting signal and an RF receiving signal in a transceiver with a transmitting unit and a receiving unit sharing an antenna, includes: a four-port circuit having port 1, port 2, port 3, and port 4, a through path being formed between the port 1 and the port 2, a first signal input to the port 1 being coupled to the port 4, a second signal input to the port 2 being coupled to the port 3, and an isolation path being formed between the port 1 and the port 4 and between the port 2 and the port 3; and an attenuator attenuating and outputting a signal output from the port 3 of the four-port circuit, and the RF transmitting signal is input to the port 1 of the four-port circuit, the RF receiving signal is input to the port 2 of the four-port circuit, and outputs of the attenuator and the port 4 of the four-port circuit are provided the receiving unit. Leakage of a transmitting signal of a transmitting unit to a receiving unit in a communication system sharing an antenna can be isolated. Furthermore, an isolation effect of a leakage signal of a transmitting unit to a receiving unit can be maximized while adaptively changing an attenuation value of a variable attenuator.

Claims15

Dependent claims

A transceiver comprising a transmitting unit, a receiving unit, and a coupling apparatus for dividing a radio frequency (RF) transmitting signal and an RF receiving signal in the transceiver with the transmitting unit and the receiving unit sharing an antenna, comprising:

a four-port circuit having port 1, port 2, port 3, and port 4, a through path being formed between the port 1 and the port 2, a first signal input to the port 1 being coupled to the port 4, a second signal input to the port 2 being coupled to the port 3, and an isolation path being formed between the port 1 and the port 3 and between the port 2 and the port 4;
and
an attenuator attenuating and outputting a signal output from the port 4 of the four-port circuit,
wherein the RF transmitting signal is input to the port 1 of the four-port circuit, the RF receiving signal is input to the port 2 of the four-port circuit, and outputs of the attenuator and the port 3 of the four-port circuit are provided the receiving unit;
wherein the attenuator is a variable attenuator operable to control variably an attenuation value, and the receiving unit includes:
a low-noise amplifier subtracting and amplifying an output signal of the attenuator from an output signal of the port 3 of the four-port circuit;
a received signal strength indicator (RSSI) measuring unit measuring an RSSI of a transmission leakage signal based on an output of the low-noise amplifier;
and
a control unit controlling an attenuation value of the attenuator based on the measured RSSI.

6 more elements

a four-port circuit having port 1, port 2, port 3, and port 4, a through path being formed between the port 1 and the port 2, a first signal input to the port 1 being coupled to the port 4, a second signal input to the port 2 being coupled to the port 3, and an isolation path being formed between the port 1 and the port 3 and between the port 2 and the port 4;
and
an attenuator attenuating and outputting a signal output from the port 4 of the four-port circuit,
wherein the RF transmitting signal is input to the port 1 of the four-port circuit, the RF receiving signal is input to the port 2 of the four-port circuit, and outputs of the attenuator and the port 3 of the four-port circuit are provided the receiving unit;
a subtracter subtracting an output signal of the attenuator from an output signal of the port 3, wherein an output of the subtracter is provided to the receiving unit;
wherein the attenuator is a variable attenuator operable to control variably an attenuation value, and the subtracter subtracts an output signal of the attenuator from an output signal of the port 3, and the receiving unit includes:
a received signal strength indicator (RSSI) measuring unit measuring an RSSI of a transmission leakage signal based on an output of the subtracter;
and
a control unit controlling an attenuation value of the attenuator based on the measured RSSI.

6 more elements

a four-port circuit having port 1, port 2, port 3, and port 4, a through path being formed between the port 1 and the port 2, a first signal input to the port 1 being coupled to the port 4, a second signal input to the port 2 being coupled to the port 3, and an isolation path being formed between the port 1 and the port 3 and between the port 2 and the port 4;
and
an attenuator attenuating and outputting a signal output from the port 4 of the four-port circuit,
wherein the RF transmitting signal is input to the port 1 of the four-port circuit the RF receiving signal is input to the port 2 of the four-port circuit, and outputs of the attenuator and the port 3 of the four-port circuit are provided the receiving unit;
wherein the attenuator is a variable attenuator operable to control variably an attenuation value, and the receiving unit includes:
a low-noise amplifier subtracting and amplifying an output signal of the attenuator from an output signal of the port 3 of the four-port circuit;
a mixer down-converting an output signal of the low-noise amplifier;
a low pass filter passing low frequency components included in an output of the mixer;
a received signal strength indicator (RSSI) measuring unit measuring an RSSI of a transmission leakage signal based on an output of the low pass filter;
and
a control unit controlling an attenuation value of the attenuator based on the measured RSSI.

8 more elements

Dependencies are inferred from the claim text.

Coupling apparatus for dividing receiving and transmitting signals and control method thereof

Life of this patent

Coupling apparatus for dividing receiving and transmitting signals and control method thereof

Life of this patent

Abstract

Claims15