Adaptive filter response systems and methods

Patent metadata

Field	Value
Publication number	US-9748916-B2
Application number	US-201414446270-A
Country	US
Kind code	B2
Filing date	Jul 29, 2014
Priority date	Jul 29, 2013
Publication date	Aug 29, 2017
Grant date	Aug 29, 2017

Abstract

The present subject matter relates to systems, devices, and methods for adaptively tuning antenna elements and/or associated filter elements to support multiple frequency bands. For example, a tunable filter having an input node and an output node can be selectively tunable to define one or more pass bands associated with one or more first signal bands and one or more reject bands associated with one or more second signal bands. The tunable filter can be configured to pass signals having frequencies within the first signal bands between the input node and the output node and to block signals having frequencies within the second signal bands. Furthermore, the tunable filter can be configured to selectively tune the pass bands to have a minimum pass band insertion loss at any of a variety of frequencies, including frequencies that are greater than and less than frequencies within the reject bands.

First claim

What is claimed is:

1. An adaptive filter comprising:
a tunable filter having an input node and an output node, the tunable filter being selectively tunable to define a pass band associated with a first signal band and a reject band associated with a second signal band, wherein the tunable filter is configured to pass signals having frequencies within the first signal band between the input node and the output node, and wherein the tunable filter is configured to block signals having frequencies within the second signal band between the input node and the output node;
wherein the tunable filter comprises one or more coupling impedance elements, the one or more coupling impedance elements comprising one or more inductors connected in series between the input node and the output node;
wherein the tunable filter is tunable both to a first mode at which a coupling impedance of the tunable filter between the input node and the output node is tuned such that the pass band has a minimum pass band insertion loss at frequencies that are less than frequencies within the reject band and to a second mode at which the coupling impedance of the tunable filter between the input node and the output node is tuned such that the pass band has a minimum pass band insertion loss at frequencies that are greater than frequencies within the reject band; and
wherein the one or more coupling impedance elements are tunable to vary the frequencies at which the minimum pass band insertion loss is achieved within the pass band.

2. The adaptive filter of claim 1 , wherein the tunable filter is configured to selectively tune the frequencies of one or both of the pass band or the reject band.

3. The adaptive filter of claim 1 , wherein the tunable filter is configured to have a total pass band loss of less than 7 dB and a reject band attenuation of more than 18 dB at corresponding frequencies of the pass band and the reject band, respectively.

4. The adaptive filter of claim 1 , wherein the tunable filter comprises:
at least one first shunt impedance element connected between the input node and a ground; and
at least one second shunt impedance element connected between the output node and the ground.

5. The adaptive filter of claim 1 , wherein the tunable filter is configured to selectively tune a frequency of the pass band by changing an impedance of the one or more coupling impedance elements by applying an electric or magnetic field.

6. The adaptive filter of claim 5 , wherein the one or more coupling impedance elements comprises one or more tunable capacitor(s).

7. The adaptive filter of claim 1 , wherein the one or more coupling impedance elements comprise:
one or more capacitors connected in parallel with the one or more inductors between the input node and the output node.

8. The adaptive filter of claim 1 , wherein the one or more coupling impedance elements comprise one or more capacitors connected in a series arrangement with the one or more inductors between the input node and the output node.

9. An adaptive filter response system for a wireless radio antenna, the system comprising:
one or more antennas in communication with a first signal path and a second signal path;
one or more first tunable filters in communication with the first signal path, the one or more first tunable filters being selectively tunable to define a first pass band associated with a first signal band and a first reject band associated with a second signal band, wherein the one or more first tunable filters is configured to pass signals having frequencies within the first signal band between the one or more antennas and the first signal path, and wherein the one or more first tunable filters is configured to block signals having frequencies within the second signal band between the one or more antennas and the first signal path;
wherein the one or more first tunable filters comprise one or more coupling impedance elements, the one or more coupling impedance elements comprising one or more inductors connected in series between an input node and an output node in the first signal path;
wherein the one or more first tunable filters is selectively tunable both to a first mode at which a coupling impedance of the tunable filter between the one or more antennas and the first signal path is tuned such that the frequencies passed by the first pass band are less than frequencies within the first reject band and to a second mode at which the coupling impedance of the tunable filter between the one or more antennas and the first signal path is tuned such that the frequencies passed by the pass band are greater than frequencies within the reject band;
wherein the one or more coupling impedance elements are tunable to vary a frequency at which a minimum pass band insertion loss is achieved within the first pass band.

10. The system of claim 9 , wherein each of the one or more first tunable filters comprises:
at least one first shunt impedance element connected between the input node and a ground; and
at least one second shunt impedance element connected between the output node and the ground.

11. The system of claim 9 , wherein the one or more first tunable filters is configured to selectively tune the frequencies of one or both of the first pass band or the first reject band.

12. The system of claim 9 , comprising one or more second tunable filters in communication with the second signal path, the one or more second tunable filters being selectively tunable to define a second pass band associated with the second signal band and a second reject band associated with the first signal band, wherein the one or more second tunable filters is configured to pass signals having frequencies within the second signal band between the one or more antennas and the second signal path, and wherein the one or more second tunable filters is configured to block signals having frequencies within the first signal band.

13. The system of claim 12 , wherein the one or more second tunable filters is configured to selectively tune the frequencies of one or both of the second pass band or the second reject band.

14. The system of claim 9 , comprising a control unit in communication with the one or more first tunable filters.

15. The system of claim 9 , comprising a remote wireless communication unit having a fixed-location antenna in communication with the one or more antennas, the remote wireless communication unit being configured to serve one or more users or devices within an area.

16. A method for tuning an adaptive filter response system, the method comprising:
connecting a tunable filter between an input node and an output node, wherein the tunable filter comprises one or more coupling impedance elements, the one or more coupling impedance elements comprising one or more inductors connected in series between the input node and the output node;
defining a pass band associated with a first signal band and a reject band associated with a second signal band, wherein signals having frequencies within the first signal band are passed between the input node and the output node, and wherein signals having frequencies within the second signal band are blocked between the input node and the output node; and
selectively tuning the tunable filter among a first mode at which a coupling impedance of the tunable filter between the input node and the output node is tuned such that the pass band has a minimum pass band insertion loss at frequencies that are less than frequencies within the reject band and a second mode at which the coupling impedance of the tunable filter between the inp

Assignees

• Wispry Inc

Inventors

• Bojer Jorgen
• Madsen Peter Dam
• Morris Iii Arthur S

Classifications

• H04L5/14

  Two-way operation using the same type of signal, i.e. duplex · CPC title

• H03H7/0115

  comprising only inductors and capacitors (H03H7/075, H03H7/09, H03H7/12, H03H7/13 take precedence) · CPC title

• H03H7/1766

  Parallel LC in series path (H03H7/1783 takes precedence) · CPC title

• H03H7/463

  Duplexers · CPC title

• H03H7/175

  Series LC in series path (H03H7/1783 takes precedence) · CPC title