Radio frequency apparatus and method with dual variable impedance components

• US 10,263,572 B2
• Filed: 10/05/2016
• Issued: 04/16/2019
• Est. Priority Date: 10/05/2016
• Status: Active Grant

• Current Assignee: Futurewei Technologies Incorporated (Huawei Investment & Holding Co., Ltd.)
• Original Assignee: Futurewei Technologies Incorporated (Huawei Investment & Holding Co., Ltd.)
• Inventors: Hamparian, Simon
• Primary Examiner(s): Bayard, Emmanuel
• Application Number:
  US15/286,481
• Publication Number:
  US 20180097480A1
• Time in Patent Office: 923 Days
• Field of Search: 375295-299
• CPC Class Codes: H03F 1/56 Modifications of input or output impedances, not otherwise provided for
• CPC Class Codes: H03F 2200/378 A variable capacitor being added in the output circuit, e.g. collector, drain, of an amplifier stage
• CPC Class Codes: H03F 2200/387 A circuit being added at the output of an amplifier to adapt the output impedance of the amplifier
• CPC Class Codes: H03F 2200/451 the amplifier being a radio frequency amplifier
• CPC Class Codes: H03F 3/19 with semiconductor devices only
• CPC Class Codes: H03F 3/245 with semiconductor devices only
• CPC Class Codes: H03F 3/68 Combinations of amplifiers, e.g. multi-channel amplifiers for stereophonics power amplifiers using a combination of several semiconductor amplifiers H03F3/211; combinations of amplifiers using coupling networks with distributed constants H03F3/602
• CPC Class Codes: H04B 1/0458 Arrangements for matching and coupling between power amplifier and antenna or between amplifying stages matching circuits in general H03H
• CPC Class Codes: H04B 1/0475 with means for limiting noise, interference or distortion H04B1/0483 takes precedence
• CPC Class Codes: H04B 2001/0408 with power amplifiers
• CPC Class Codes: H04B 7/0617 for beam forming

Abstract

A radio frequency (RF) transmitter apparatus and method are provided with dual variable impedance components. Included is at least one RF transmitter with a power amplifier and a filter. Further, a first variable impedance component is in electrical communication between the filter and an antenna port. Also included is a second variable impedance component in electrical communication between the power amplifier and the filter.

Claims

1. An apparatus, comprising:

at least one radio frequency (RF) transmitter including;

a power amplifier configured to power amplify a signal;

a filter configured to remove a component of the signal;

an antenna port coupled to at least one antenna;

a first variable impedance component in electrical communication between the filter and the antenna port to receive an output of the filter and to provide an input to the antenna port, wherein the first variable impedance component is configured to have a tunable impedance that is tunable during operation based on a first return loss at the filter; and

a second variable impedance component in electrical communication between the power amplifier and the filter to receive an output of the power amplifier and to provide an input to the filter, wherein the second variable impedance component is configured to have a tunable impedance that is tunable during operation based on a second return loss at the filter; and

wherein impedance of the first variable impedance component and impedance of the second variable impedance component are tuned based on return losses at the filter such that the at least one RF transmitter has a voltage standing wave ratio (VSWR) that satisfies a predetermined VSWR requirement.

2. The apparatus of claim 1, wherein the filter includes a bandpass filter.

3. The apparatus of claim 1, wherein the filter includes a film bulk acoustic resonator (FBAR) filter.

4. The apparatus of claim 1, wherein at least one of the first variable impedance component or the second variable impedance component includes a tunable matching network.

5. The apparatus of claim 4, wherein the tunable matching network includes a micro strip line element and a pair of variable capacitive components.

6. The apparatus of claim 4, wherein the tunable matching network is configured for exhibiting different impedances, for each of a plurality of antenna beaming angles between zero (0) and three-hundred and sixty (360) degrees.

7. The apparatus of claim 1, wherein the at least one RF transmitter includes a plurality of RF transmitters that are part of a multiple-input-multiple-output (MIMO)-capable system.

8. The apparatus of claim 1, wherein the first variable impedance component and the second variable impedance component are configured to cooperate to compensate for the VSWR of up to five-to-one (5:

1).

9. The apparatus of claim 1, wherein the first variable impedance component and the second variable impedance component are configured to cooperate to compensate for the VSWR of five-to-one (5:

1), for each of a plurality of antenna beaming angles between zero (0) and three-hundred and sixty (360) degrees.

10. The apparatus of claim 1, wherein the first variable impedance component and the second variable impedance component are configured to cooperate to compensate for a delay of the filter of up to thirty (30) nanoseconds.

11. The apparatus of claim 1, wherein the first variable impedance component and the second variable impedance component are configured to cooperate to compensate for a delay of the filter of up to thirty (30) nanoseconds, for each of a plurality of antenna beaming angles between zero (0) and three-hundred and sixty (360) degrees.

12. The apparatus of claim 1, wherein the at least one RF transmitter further includes an additional component in electrical communication between the first variable impedance component and the filter, for measuring a forward power and a reflected power.

13. The apparatus of claim 12, wherein at least one of the first variable impedance component or the second variable impedance component is configured for exhibiting variable impedance, based on the measured forward power and the measured reflected power.

14. The apparatus of claim 1, wherein the apparatus is configured for measuring a first return loss at an output of the filter, and controlling a first variable impedance of the first variable impedance component, based on the first return loss.

15. The apparatus of claim 14, wherein the apparatus is configured for measuring a second return loss at an input of the filter, and controlling a second variable impedance of the second variable impedance component, based on the second return loss.

16. The apparatus of claim 15, wherein the apparatus is configured for measuring the second return loss at the input of the filter, and controlling the second variable impedance of the second variable impedance component, after measuring the first return loss at the output of the filter, and controlling the first variable impedance of the first variable impedance component.

17. The apparatus of claim 15, wherein the apparatus is configured for repeating each of the measuring and the controlling for each of a plurality of antenna beaming angles between zero (0) and three-hundred and sixty (360) degrees.

18. The apparatus of claim 1, wherein the first variable impedance component and the second variable impedance component are tunable during operation for compensating for impedance mismatch.

19. The apparatus of claim 1, wherein the first variable impedance component and the second variable impedance component are tunable during operation for compensating for impedance mismatch in connection with each of a plurality of coupled antennas.

20. A method, comprising:

controlling a first variable impedance component, the first variable impedance component being in electrical communication between a filter and an antenna port of at least one radio frequency (RF) transmitter to receive an output of the filter and to provide an input to the antenna port, wherein the first variable impedance component is configured to have a tunable impedance that is tunable during operation based on a first return loss at the filter; and

controlling a second variable impedance component, the second variable impedance component being in electrical communication between a power amplifier and the filter of the at least one RF transmitter to receive an output of the power amplifier and to provide an input to the filter, wherein the second variable impedance component is configured to have a tunable impedance that is tunable during operation based on a second return loss at the filter; and

wherein the power amplifier is configured to power amplify a signal;

wherein the filter is configured to remove a component of the signal; and

wherein impedance of the first variable impedance component and impedance of the second variable impedance component are controlled to be tuned based on return losses at the filter, such that the at least one RF transmitter has a voltage standing wave ratio (VSWR) that satisfies a predetermined VSWR requirement.

21. The method of claim 20, and further comprising measuring a first return loss at an output of the filter;

and controlling a first variable impedance of the first variable impedance component, based on the first return loss.

22. The method of claim 21, and further comprising measuring a second return loss at an input of the filter;

and controlling a second variable impedance of the second variable impedance component, based on the second return loss.

23. A radio frequency (RF) transmitter comprising:

a power amplifier that is configured to produce a power amplified output;

an antenna port coupled to at least one antenna;

a filter coupled to receive the power amplified output, the filter configured to produce a filtered power amplified output that has removed therefrom a component of the power amplified output;

a first variable impedance element coupled between the filter and the antenna port to receive an output of the filter and to provide an input to the antenna port, wherein the first variable impedance element is configured to have a tunable impedance that is tunable during operation based on a first return loss at the filter;

a second variable impedance element coupled between the power amplifier and the filter to receive an output of the power amplifier and to provide an input to the filter, wherein the second variable impedance element is configured to have a tunable impedance that is tunable during operation based on a second return loss at the filter; and

circuitry configured to provide control signals to the first and second variable impedance elements to tune impedances of the first and second variable impedance elements based on return losses at the filter during operation such that the RF transmitter has a voltage standing wave ratio (VSWR) on a transmit path that meets a predetermined VSWR requirement.

24. The transmitter of claim 23, wherein the filter includes at least one of a bandpass filter and a film bulk acoustic resonator (FBAR) filter.

25. The transmitter of claim 23, further including a tunable matching network.

26. The transmitter of claim 25, wherein the tunable matching network includes a micro strip line element and a pair of variable capacitive components.