Equalization of frequency-dependent gain

Patent metadata

Field	Value
Publication number	US-10063206-B2
Application number	US-201715808882-A
Country	US
Kind code	B2
Filing date	Nov 9, 2017
Priority date	Feb 18, 2014
Publication date	Aug 28, 2018
Grant date	Aug 28, 2018

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:
measuring a frequency-dependent gain of a device signal path in an electronic device;
configuring the variable gain compensation circuit to establish the variable frequency-dependent gain to compensate for the measured frequency-dependent gain, wherein the configuring 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;
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.

2. The method of claim 1 , wherein the measured frequency-dependent gain does not satisfy a target characteristic, and the configuring the variable gain compensation circuit establishes a composite frequency-dependent gain of the device signal path that satisfies the target characteristic.

3. The method of claim 2 , wherein the target characteristic is at least one of a gain slope and a gain range of the composite frequency-dependent gain.

4. The method of claim 1 , wherein the measuring and the configuring comprises iteratively configuring the variable gain compensation circuit in a plurality of configurations and measuring corresponding composite frequency-dependent gain of the device signal path at each of the plurality of configurations.

5. The method of claim 4 , wherein the iteratively configuring the variable gain compensation circuit in the plurality of configurations and measuring corresponding composite frequency-dependent gain of the device signal path at each of the plurality of configurations is performed until the measuring composite frequency-dependent gain satisfies a target characteristic.

6. The method of claim 4 , wherein the plurality of configurations includes:
a first configuration in which the first pair of switches are closed and the second pair of switches are opened to establish the first signal path and preclude the second signal path to form a first frequency-dependent profile of the variable frequency-dependent gain; and
a second configuration in which the first pair of switches are opened and the second pair of switches are closed to preclude the first signal path and establish the second signal path to form a second frequency-dependent profile of the variable frequency-dependent gain.

7. The method of claim 6 , wherein the plurality of configurations further includes:
a third configuration in which the first pair of switches are closed and the second pair of switches are closed to establish the first signal path and the second signal path to form a third frequency-dependent profile of the variable frequency-dependent gain.

8. The method of claim 7 , wherein at least one of the first, second and third frequency-dependent profiles corresponds to a polynomial having an order greater than one.

9. The method of claim 4 , further comprising:
selecting a configuration from the plurality of configurations based on the measured composite frequency-dependent gain, wherein the controlling of the first and second pairs of switches is based on the selected configuration.

10. The method of claim 9 , wherein the selected configuration provides the smallest variation in the target characteristic from among the plurality of configurations.

11. The method of claim 9 , wherein the selected configuration is closest to a predetermined frequency-dependent target gain profile from among the plurality of configurations.

12. The method of claim 1 , 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 signal path.

14. The method of claim 1 , 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 measured frequency-dependent gain of the electronic device is due to frequency-dependent gain contributions of components along the device signal path of the electronic device.

17. The method of claim 1 , wherein the variable frequency-dependent gain is complimentary to the measured frequency-dependent gain.

18. The method of claim 1 , wherein the variable frequency-dependent gain adjusts a composite frequency-dependent gain of the electronic device to within an acceptable range of gain values.

19. The method of claim 1 , wherein the device signal path is one of a transmit path and a receive path of the electronic device.

20. The method of claim 1 , 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.

Assignees

• Viasat Inc

Inventors

• Buer Kenneth V
• Lyons Michael R

Classifications

• H03F3/245

  with semiconductor devices only · CPC title

• H04B1/40

  Circuits · CPC title

• H04L25/03159

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

• H04B7/1853

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

• H03G3/3042 Primary

  in modulators, frequency-changers, transmitters or power amplifiers · CPC title