System providing reduced intermodulation distortion

Patent metadata

Field	Value
Publication number	US-9438288-B2
Application number	US-201213708538-A
Country	US
Kind code	B2
Filing date	Dec 7, 2012
Priority date	Dec 7, 2012
Publication date	Sep 6, 2016
Grant date	Sep 6, 2016

Abstract

A system divides a signal into first and second portions and transmits the first and second portions through different signal paths between a first port and a second port. Each of the signal paths comprises an amplifier arranged in sequence with a passive device. Phase shifters may be included in each of the signal paths to produce cancellation of intermodulation products by destructive interference.

First claim

The invention claimed is:

1. A system, comprising:
a first port configured to receive a transmit signal;
a second port configured to transmit the transmit signal;
a first transmit path configured to transmit a first portion of the transmit signal from the first port to the second port and comprising a first transmit amplifier followed by a first frequency filter; and
a second transmit path configured to transmit a second portion of the transmit signal from the first port to the second port and comprising a second transmit amplifier followed by a second frequency filter, wherein the first and second frequency filters have substantially the same phase responses and amplitude responses as each other.

2. The system of claim 1 , further comprising:
a first phase shifter connected between the first port and the first transmit amplifier and configured to phase shift the first portion of the transmit signal by a first amount in a positive direction;
a second phase shifter connected between the first port and the second transmit amplifier and configured to phase shift the second portion of the transmit signal by the first amount in a negative direction;
a third phase shifter connected between the first frequency filter and the second port and configured to phase shift the first portion of the transmit signal by the first amount in the negative direction; and
a fourth phase shifter connected between the second frequency filter and the second port and configured to phase shift the second portion of the transmit signal by the first amount in the positive direction.

3. The system of claim 1 , further comprising:
a first phase shifter connected between the transmit port and the first transmit amplifier and configured to phase shift the first portion of the transmit signal by a first amount in a first direction; and
a second phase shifter connected between the second frequency filter and the second port and configured to phase shift the second portion of the transmit signal by the first amount in the first direction.

4. A system, comprising:
a first port configured to receive a transmit signal;
a second port configured to transmit the transmit signal;
a first transmit path configured to transmit a first portion of the transmit signal from the first port to the second port and comprising a first transmit amplifier followed by a first passive device; and
a second transmit path configured to transmit a second portion of the transmit signal from the first port to the second port and comprising a second transmit amplifier followed by a second passive device, wherein the first and second passive devices have substantially the same electrical characteristics as each other,
wherein the first port is a transmit port and the second port is a transmit/receive (T/R) port, and wherein the T/R port is further configured to receive a receive signal, the system further comprising:
a first receive path configured to transmit a first portion of the receive signal from the T/R port to a receive port and comprising a third passive device followed by a first receive amplifier; and
a second receive path configured to transmit a first portion of the receive signal from the T/R port to the receive port and comprising a fourth passive device followed by a first receive amplifier, wherein the third and fourth passive devices have substantially matched electrical characteristics.

5. The system of claim 4 , further comprising:
a first phase shifter connected between the transmit port and the first transmit amplifier and configured to phase shift the first portion of the transmit signal by a first amount in a positive direction;
a second phase shifter connected between the transmit port and the second transmit amplifiers and configured to phase shift the second portion of the transmit signal by approximately the first amount in a negative direction;
a third phase shifter connected between the receive port and the first receive amplifier and configured to phase shift the first portion of the receive signal by approximately the first amount in the positive direction;
a fourth phase shifter connected between the receive port and the second receive amplifier and configured to phase shift the second portion of the receive signal by approximately the first amount in the negative direction;
a fifth phase shifter connected between the first passive device and the T/R port and between the third passive device and the T/R port and configured to phase shift the respective first portions of the transmit signal and the receive signal by approximately the first amount in the negative direction; and
a sixth phase shifter connected between the second passive device and the T/R port and between the fourth passive device and the T/R port and configured to phase shift the respective first portions of the transmit signal and the receive signal by approximately the first amount in the positive direction.

6. The system of claim 5 , further comprising:
a combining device connected between the T/R port and the first and second passive devices and configured to combine the first and second portions of the transmit signal to produce the transmit signal at the T/R port; and
a splitting device connected between the T/R port and the third and fourth passive devices and configured to split the receive signal to produce the first and second portions of the receive signal transmitted through the respective first and second receive pathways.

7. The system of claim 6 , wherein the combining device and the splitting device comprise a single Wilkinson device.

8. The system of claim 4 , wherein the T/R port is connected to an antenna configured to transmit the transmit signal and receive the receive signal.

9. The system of claim 4 , wherein the first and second passive devices are formed on a first chip, and the third and fourth passive devices are formed on a second chip.

10. The system of claim 4 , wherein at least one of the first through fourth passive devices comprises an acoustic resonator.

11. The system of claim 4 , wherein the first and second transmit amplifiers each comprise a power amplifier, and the first and second receive amplifiers each comprise a low noise amplifier.

12. The system of claim 4 , wherein the first and third passive devices form a first duplexer, and the second and fourth passive devices form a second duplexer.

13. The system of claim 2 , wherein the first amount is approximately 22.5 degrees.

14. The system of claim 5 , wherein the first amount is one of: approximately 22.5 degrees and approximately 45 degrees.

15. A method, comprising:
dividing a transmit signal into first and second portions;
transmitting the first portion of the transmit signal through a first transmit path arranged between a first port and a second port and comprising a first transmit amplifier followed by a first frequency filter;
transmitting the second portion of the transmit signal through a second transmit path arranged between the first port and the second port and comprising a second transmit amplifier followed by a second frequency filter, wherein the first and second frequency filters have substantially the same phase responses and amplitude responses as each other; and
combining the first and second portions of the transmit signal and transmitting a resulting signal to the second port.

16. The method of claim 15 , wherein the first transmit path further comprises a first phase shifter connected between the first port and the first transmit amplifier and configured to phase shift the first portion of the transmit signal by a first

Assignees

• Avago Technologies General Ip

Inventors

• Feld David A
• Jansen Bart

Classifications

• H04B15/04

  the interference being caused by substantially sinusoidal oscillations, e.g. in a receiver or in a tape-recorder · CPC title

• H04B1/109 Primary

  by improving strong signal performance of the receiver when strong unwanted signals are present at the receiver input · CPC title

• H04B1/525

  with means for reducing leakage of transmitter signal into the receiver · CPC title

• H04B15/06

  by local oscillators of receivers · CPC title