Equalization of frequency-dependent gain

Patent metadata

Field	Value
Publication number	US-10224893-B2
Application number	US-201816051228-A
Country	US
Kind code	B2
Filing date	Jul 31, 2018
Priority date	Feb 18, 2014
Publication date	Mar 5, 2019
Grant date	Mar 5, 2019

Abstract

Systems, devices, and methods for determining and establishing frequency-dependent gain compensation in wide bandwidth communication systems are disclosed. Variable frequency-dependent gain compensation circuits, or variable equalizers, have settings that configure them to establish discrete frequency-dependent gain compensation. The frequency-dependent gain compensation can include various types and levels of gain slope and/or ripple. The settings of the variable equalizers can be set by control signals established a control circuit in response to signals from an external computer. The variable equalizers are coupled to other circuits or devices and the frequency-dependent gain of the combined circuit are measured. The settings of the variable equalizer are then changed to establish an optimal frequency-dependent gain profile or frequency-dependent gain that is closest to a predetermined frequency-dependent target gain profile. The settings can then be saved in a memory or register.

First claim

What is claimed is:

1. A method of operating a variable gain compensation circuit to establish a variable frequency-dependent gain, the method comprising:
providing an electronic device including the variable gain compensation circuit along a device signal path, wherein the variable frequency-dependent gain of the variable gain compensation circuit is configurable from among a plurality of frequency-dependent profiles;
configuring the variable gain compensation circuit to establish an initial frequency-dependent profile of the plurality of frequency-dependent profiles, wherein the initial frequency-dependent profile is based on final frequency-dependent profiles of other variable gain compensation circuits that provide compensation of other device signal paths within other electronic devices;
measuring a first composite frequency-dependent gain of the device signal path while the variable gain compensation circuit is configured to establish the initial frequency-dependent profile;
selecting, based on the measured composite frequency-dependent gain, a final frequency-dependent profile for the variable gain compensation circuit from among a subset of the plurality of frequency-dependent profiles; and
configuring the variable gain compensation circuit to establish the selected final frequency-dependent profile.

2. The method of claim 1 , wherein the subset is a predetermined number of the plurality of frequency-dependent profiles.

3. The method of claim 1 , wherein the initial frequency-dependent profile is within the subset and the configuring, the measuring, and the selecting comprises:
iteratively configuring the variable gain compensation circuit in each of the subset of the plurality of frequency-dependent profiles and measuring corresponding composite frequency-dependent gain of the device signal path at each of the subset of frequency-dependent profiles;
selecting a particular frequency-dependent profile of the subset of the frequency-dependent profiles as the final frequency-dependent profile based on comparison of the measured corresponding composite frequency-dependent gain to a target characteristic.

4. The method of claim 3 , wherein the particular frequency-dependent profile has the measured corresponding composite frequency-dependent gain that is closest to the target characteristic.

5. The method of claim 1 , wherein the selecting comprises:
selecting the initial frequency-dependent profile as the final frequency-dependent profile if the measured composite frequency-dependent gain satisfies a target characteristic; and
selecting the final frequency-dependent profile from among the subset of the plurality of frequency-dependent profiles if the measured composite frequency-dependent gain does not satisfy the target characteristic.

6. The method of claim 5 , wherein the target characteristic is at least one of a gain slope and a gain range of the composite frequency-dependent gain.

7. The method of claim 5 , wherein the final frequency-dependent profile provides the smallest variation in the target characteristic from among the subset of the plurality of frequency-dependent profiles.

8. The method of claim 7 , wherein the final frequency-dependent profile is closest to a predetermined frequency-dependent target gain profile from among the subset of the plurality of frequency-dependent profiles.

9. The method of claim 1 , wherein at least one of the plurality of frequency-dependent profiles corresponds to a polynomial having an order greater than one.

10. The method of claim 1 , wherein the configuring the variable gain compensation circuit to establish the final frequency-dependent profile comprises:
controlling a first pair of switches to selectively form a first signal path through a first circuit element having a first frequency-dependent gain; and
controlling a second pair of switches independently of the first pair of switches to selectively form a second signal path through a second circuit element having a second frequency-dependent gain, wherein the second frequency-dependent gain is different than the first frequency-dependent gain.

11. The method of claim 10 , wherein:
controlling the first pair of switches comprises configuring the first pair of switches into one of an open or closed arrangement; and
controlling the second pair of switches comprises configuring the second set of switches into one of an open or closed arrangement independent of whether the first pair of switches are configured in the open or closed arrangement.

12. The method of claim 10 , wherein the first signal path and the second signal path are each between an input terminal and an output terminal of the variable gain compensation circuit.

13. The method of claim 12 , wherein the first signal path is in parallel with the second circuit path.

14. The method of claim 10 , wherein the variable compensation circuit further includes a third circuit element along a third signal path.

15. The method of claim 14 , wherein the third circuit element is an amplifier.

16. The method of claim 1 , wherein the electronic device includes components along the device signal path.

17. The method of claim 1 , wherein the initial frequency-dependent profile is a final frequency-dependent profile of at least some of other variable gain compensation circuits.

18. The method of claim 17 , wherein the initial frequency-dependent profile is the final frequency-dependent profile of most of the other variable gain compensation circuits.

Assignees

• Viasat Inc

Inventors

• Buer Kenneth V
• Lyons Michael R

Classifications

• H03F2200/451

  the amplifier being a radio frequency amplifier · CPC title

• H03F3/245

  with semiconductor devices only · CPC title

• H04B7/1853

  Satellite systems for providing telephony service to a mobile station, i.e. mobile satellite service (for selecting H04W) · CPC title

• H03F3/19

  with semiconductor devices only · CPC title

• H04L25/03159

  operating in the frequency domain (H04L25/03165, H04L25/03178 take precedence) · CPC title