Equalization of frequency-dependent gain

Patent metadata

Field	Value
Publication number	US-9484878-B2
Application number	US-201514618484-A
Country	US
Kind code	B2
Filing date	Feb 10, 2015
Priority date	Feb 18, 2014
Publication date	Nov 1, 2016
Grant date	Nov 1, 2016

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 circuit comprising:
a variable gain compensation circuit to establish a variable frequency-dependent gain; and
a control circuit comprising an input terminal and coupled to the variable gain compensation circuit, wherein the control circuit is configured to control the variable frequency-dependent gain of the variable gain compensation circuit in response to a signal received on the input terminal from an external source, wherein the variable gain compensation circuit comprises a plurality of N variable gain compensation devices to establish a plurality of N corresponding component variable frequency-dependent gains, and wherein the variable frequency-dependent gain of the variable gain compensation circuit is a composite of at least some of the plurality of N component variable frequency-dependent gains, wherein the plurality of N variable gain compensation devices each comprise:
an inductor;
a capacitor;
a resistor; and
an amplifier, wherein each of the inductor, the capacitor, and the resistor is selectively coupled to the amplifier in parallel through one or more corresponding switches.

2. The circuit of claim 1 , wherein the control circuit further comprises a register, and wherein the control circuit establishes a control signal to control the variable frequency-dependent gain of the variable gain compensation circuit in accordance with a predetermined setting stored in the register.

3. The circuit of claim 1 , wherein the plurality of N variable gain compensation devices are the same and the corresponding plurality of N component variable frequency-dependent gains are approximately equal to each other.

4. The circuit of claim 1 , wherein at least one of the plurality of N variable gain compensation devices is different from at least one other of the plurality of N variable gain compensation devices, and wherein at least one of the corresponding plurality of N component variable frequency-dependent gains is different from at least one other of the plurality of N component variable frequency-dependent gains.

5. The circuit of claim 1 , wherein the variable frequency-dependent gain comprises a gain slope.

6. The circuit of claim 1 , wherein the variable frequency-dependent gain comprises a gain ripple.

7. The circuit of claim 1 , wherein the variable gain compensation circuit comprises a plurality of M possible configurations to establish a plurality of M corresponding discrete frequency-dependent gains.

8. The circuit of claim 1 , wherein the circuit is a monolithic microwave integrated circuit (MMIC).

9. A transceiver circuit comprising:
a transmit path comprising a first variable gain compensation circuit to establish a variable frequency-dependent transmit gain;
a receive path comprising a second variable gain compensation circuit to establish a variable frequency-dependent receive gain; and
a control circuit comprising an input terminal coupled to the first variable gain compensation circuit and the second variable gain compensation circuit, wherein the control circuit is configured to control the variable frequency-dependent transmit gain of the first variable gain compensation circuit and the variable frequency-dependent receive gain of the second variable gain compensation circuit in response to a signal received on the input terminal from an external source;
wherein each of the first and second variable gain compensation circuits comprises a corresponding plurality of N variable gain compensation devices to establish a plurality of N corresponding component variable frequency-dependent gains, and wherein the variable frequency-dependent gain of each of the first and second variable gain compensation circuits is a corresponding composite of at least some of the plurality of N corresponding component variable frequency-dependent gains, wherein the plurality of N variable gain compensation devices each comprise:
an inductor;
a capacitor;
a resistor; and
an amplifier, wherein each of the inductor, the capacitor, and the resistor is selectively coupled to the amplifier in parallel through one or more corresponding switches.

10. The transceiver circuit of claim 9 , wherein the transmit path comprises a first plurality of signal processing devices, wherein the variable frequency-dependent transmit gain of the first variable gain compensation circuit is set in response to a first frequency-dependent gain of the first plurality of signal processing devices, wherein the receive path comprises a second plurality of signal processing devices, and wherein the variable frequency-dependent receive gain of the second variable gain compensation circuit is set in response to a second frequency-dependent gain of the second plurality of signal processing devices.

11. The transceiver circuit of claim 9 , wherein the control circuit comprises a register, and wherein the control circuit establishes one or more control signals to control the variable frequency-dependent transmit gain of the first variable gain compensation circuit and the variable frequency-dependent receive gain of the second variable gain compensation circuit in accordance with a predetermined setting stored in the register.

12. The transceiver circuit of claim 9 , wherein the variable frequency-dependent transmit gain of the first variable gain compensation circuit is set to establish substantially flat frequency-dependent gain through the transmit path, and wherein the variable frequency-dependent receive gain of the second variable gain compensation circuit is set to establish substantially flat frequency-dependent gain through the receive path.

13. The transceiver circuit of claim 12 , wherein the substantially flat frequency-dependent gain through the transmit path corresponds to a reduction in a dynamic range of power output of the transmit path.

Assignees

• Viasat Inc

Inventors

• Buer Kenneth V
• Lyons Michael R

Classifications

• H04B1/40

  Circuits · 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

• H03F2200/451

  the amplifier being a radio frequency amplifier · CPC title