DUPLEXING APPARATUS, WIRELESS DEVICES AND RELATED METHODS

• US 20150222412A1
• Filed: 02/04/2015
• Published: 08/06/2015
• Est. Priority Date: 02/04/2014
• Status: Active Grant

• Current Assignee: U-Blox AG (u-blox Holding AG)
• Original Assignee: U-Blox AG (u-blox Holding AG)
• Inventors: LAUGHLIN, Leo, Marshall, Christopher
• Granted Patent: US 9,929,854 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04B 1/525 with means for reducing leakage of transmitter signal into the receiver
• CPC Class Codes: H04B 1/581 using a transformer
• CPC Class Codes: H04L 5/1438 Negotiation of transmission parameters prior to communication modified according to link quality H04L1/0001
• CPC Class Codes: H04W 24/08 Testing, supervising or monitoring using real traffic
• CPC Class Codes: H04W 72/0453 Resources in frequency domain, e.g. a carrier in FDMA

Abstract

The invention provides duplexing apparatus, wireless devices and methods for duplexing signals in which measurements are taken at multiple frequencies across a frequency band of interest, and in which a balancing impedance is controlled as a function of those measurements. Isolation between the RX and TX nodes is enhanced across the frequency band as a result.

Claims

1. An apparatus for duplexing signals to be transmitted wirelessly and signals received wirelessly by an antenna, comprising:

a hybrid junction comprising an antenna node for coupling to the antenna, an input node for receiving a signal to be transmitted by the antenna, an output node for outputting a signal received wirelessly by the antenna, and a balancing node;

a variable impedance coupled to the balancing node; and

a controller arranged to;

a) set the variable impedance to a predetermined impedance;

b) transmit a signal at a first frequency in a first frequency band of interest;

c) measure a signal at the output node at at least one second frequency in a second frequency band of interest as a result of the signal transmitted at the first frequency;

d) repeat operation b) and/or operation c) for at least one other frequency in the first frequency band of interest and/or at least one other frequency in the second frequency band of interest; and

e) control the variable impedance as a function of the measurements in operation c).

2. The apparatus according to claim 1, wherein the first frequency band of interest and the second frequency band of interest do not overlap, overlap partially or overlap completely.

3. The apparatus according to claim 1, wherein the first frequency and the at least one second frequency are identical or different.

4. The apparatus according to claim 1, wherein the controller is further arranged to:

for each measurement in operation c), calculate respective quantities representing interference and balance of the hybrid junction; and

control the variable impedance as a function of the plurality of quantities.

5. The apparatus according to claim 1, wherein the controller is configured to control the variable impedance such that a reflection coefficient at the balancing node is proportional to a mean reflection coefficient of the antenna over the first or second frequency band of interest.

6. The apparatus according to claim 1, wherein the controller is arranged to control the variable impedance further as a function of at least one of a power density with which signals are transmitted by the antenna as a function of frequency, and a filter gain with which signals are received as a function of frequency.

7. The apparatus according to claim 1, wherein the controller is configured to:

set the variable impedance to a second predetermined impedance;

repeat operations b) to d) for the second predetermined impedance in order to obtain a second plurality of measurements at the output node; and

control the variable impedance further as a function of the second plurality of measurements.

8. The apparatus according to claim 1, wherein the controller is configured to carry out operations a) to e) periodically.

9. The apparatus according to claim 1, wherein the controller is arranged to control the variable impedance to take an impedance proportional to

10. A wireless device comprising an antenna and an apparatus for duplexing signals to be transmitted wirelessly and signals received wirelessly by an antenna, comprising:

a hybrid junction comprising an antenna node for coupling to the antenna, an input node for receiving a signal to be transmitted by the antenna, an output node for outputting a signal received wirelessly by the antenna, and a balancing node;

a variable impedance coupled to the balancing node; and

a controller arranged to;

a) set the variable impedance to a predetermined impedance;

b) transmit a signal at a first frequency in a first frequency band of interest;

c) measure a signal at the output node at at least one second frequency in a second frequency band of interest as a result of the signal transmitted at the first frequency;

d) repeat operation b) and/or operation c) for at least one other frequency in the first frequency band of interest and/or at least one other frequency in the second frequency band of interest; and

e) control the variable impedance as a function of the measurements in operation c).

11. A method of duplexing signals to be transmitted wirelessly and signals received wirelessly by an antenna, in a system comprising a hybrid junction, the hybrid junction comprising an antenna node for coupling to the antenna, an input node for receiving a signal to be transmitted by the antenna, an output node for outputting a signal received wirelessly by the antenna, and a balancing node, the method comprising:

a) setting a variable impedance coupled to the balancing node to a predetermined impedance;

b) transmitting a signal at a first frequency in a first frequency band of interest;

c) measuring a signal at the output node at at least one second frequency in a second frequency band of interest as a result of the signal transmitted at the first frequency;

d) repeating operation b) and/or operation c) for at least one other frequency in the first frequency band of interest and/or at least one other frequency in the second frequency band of interest; and

e) controlling the variable impedance as a function of the measurements in operation c).

12. The method according to claim 11, wherein the first frequency band of interest and the second frequency band of interest do not overlap, overlap partially or overlap completely.

13. The method according to claim 11, wherein the first frequency and the at least one second frequency are identical or different.

14. The method according to claim 11, further comprising:

for each measurement in operation c), calculating respective quantities representing interference and balance of the hybrid junction; and

controlling the variable impedance as a function of the plurality of quantities.

15. The method according to claim 11, wherein the variable impedance is controlled such that a reflection coefficient at the balancing node is proportional to a mean reflection coefficient of the antenna over the first or second frequency band of interest.

16. The method according to claim 11, wherein the variable impedance is controlled further as a function of at least one of a power density with which signals are transmitted by the antenna as a function of frequency, and a filter gain with which signals are received as a function of frequency.

17. The method according to claim 11, further comprising:

setting the variable impedance to a second predetermined impedance;

repeating operations b) to d) for the second predetermined impedance in order to obtaining a second plurality of measurements; and

controlling the variable impedance further as a function of the second plurality of measurements.

18. The method according to claim 11, further comprising carrying out operations a) to e) periodically.

19. The method according to claim 11, wherein the variable impedance is controlled to take an impedance proportional to