Method and system for multiple tuner application using a low noise broadband distribution amplifier

• US 8,437,719 B2
• Filed: 09/13/2012
• Issued: 05/07/2013
• Est. Priority Date: 08/15/2001
• Status: Expired due to Fees

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Fanous, Adel, Dauphinee, Leonard, Burns, Lawrence M., McMullin, Donald
• Primary Examiner(s): Nguyen, Simon
• Application Number:
  US13/614,811
• Publication Number:
  US 20130021100A1
• Time in Patent Office: 236 Days
• Field of Search: 455/132, 455/136, 455/138, 455/189, 455/232.1, 4552341-2342, 455/239.1, 455/240.1, 455/241.1, 4552451-2511, 455/253.2, 455/333, 455/341, 330/124.R, 330/278, 330/295
• US Class Current: 455/232.1
• CPC Class Codes: H03F 2200/294 the amplifier being a low noise amplifier [LNA]
• CPC Class Codes: H03F 2200/372 Noise reduction and elimination in amplifier
• CPC Class Codes: H03F 2203/45302 the common gate stage of a cascode dif amp being controlled
• CPC Class Codes: H03F 2203/45311 the common gate stage of a cascode dif amp being implemented by multiple transistors
• CPC Class Codes: H03F 2203/45464 the CSC comprising one or more coils
• CPC Class Codes: H03F 2203/45466 the CSC being controlled, e.g. by a signal derived from a non specified place in the dif amp circuit
• CPC Class Codes: H03F 2203/45638 the LC comprising one or more coils
• CPC Class Codes: H03F 2203/45696 the LC comprising more than two resistors
• CPC Class Codes: H03F 3/45183 Long tailed pairs H03F3/4521, H03F3/45237 take precedence
• CPC Class Codes: H03F 3/45201 Non-folded cascode stages
• CPC Class Codes: H03F 3/45475 using IC blocks as the active amplifying circuit
• CPC Class Codes: H03G 1/0029 using FETs
• CPC Class Codes: H03G 3/3036 in high-frequency amplifiers or in frequency-changers H03G3/3052, H03G3/32, H03G3/34 take precedence
• CPC Class Codes: H03G 3/3052 in bandpass amplifiers (H.F. or I.F.) or in frequency-changers used in a (super)heterodyne receiver H03G3/32, H03G3/34 take precedence

Abstract

An active splitter circuit arrangement includes a first amplification module having a number of first input ports and first output ports. The first amplification module is configured to provide first stage amplification to a received input signal and produce from the amplified input signal a number of output signals, each substantially matching the input signal. Also included is a first gain control device configured to control a gain of the first amplification module. Next, a number of second amplification modules corresponding to the number of output signals has a number of second input ports respectively coupled to the first output ports. Each second amplification module is configured to receive a control signal from the second gain control device, provide second stage amplification to a corresponding one of the number of output signals based upon the control signal and produce an amplified output signal.

Claims

1. A tuner system, comprising:

a first amplifier configured to amplify an input signal according to a first gain to provide an output signal;

a plurality of second amplifiers configured to amplify the output signal according to a plurality of second gains to provide a plurality of second output signals;

a first gain control device configured to adjust the first gain to maintain signal levels of the plurality of second output signals above a threshold signal level; and

a plurality of second gain control devices configured to adjust the plurality of second gains according to a modulation type of the input signal.

2. The tuner system of claim 1, wherein the first amplifier comprises:

a plurality of differential amplifiers including a first subset and a second subset of differential amplifiers; and

an attenuator, coupled between the first subset and the second subset of differential amplifiers, configured to attenuate the input signal to provide an attenuated input signal,

wherein the first subset of differential amplifiers is configured to amplify the input signal, and

wherein the second subset of differential amplifiers is configured to amplify the attenuated input signal.

3. The tuner system of claim 2, wherein each differential amplifier from among the second subset of differential amplifiers is further configured to amplify the attenuated input signal.

4. The tuner system of claim 2, wherein the first gain control device is further configured to activate differential amplifiers from among the first and the second subsets of differential amplifiers to adjust the first gain.

5. The tuner system of claim 1, wherein the plurality of second gain control devices comprises:

a plurality of demodulators.

6. The tuner system of claim 5, further comprising:

a tuner configured to tune a second output signal from among the plurality of second output signals in accordance with a third gain, and

wherein a demodulator from among the plurality of demodulators is further configured to adjust the third gain.

7. The tuner system of claim 6, wherein the tuner is from among a plurality of tuners, and

wherein the plurality of demodulators is further configured to control a plurality of tuner gains corresponding to the plurality of tuners.

8. The tuner system of claim 1, wherein the first gain control device comprises:

a power detector configured to detect an output signal level of the output signal and to adjust the first gain utilizing a control signal generated according to a difference between the output signal level and the threshold signal level.

9. The tuner system of claim 1, wherein the tuner system is coupled to a television tuning device.

10. A tuner system, comprising:

a first amplifier configured to amplify an input signal to provide an output signal having a first output signal level;

a plurality of second amplifiers configured to amplify the output signal according to a plurality of gains to provide a plurality of second output signals having a plurality of second output signal levels; and

a gain control device configured to;

detect a second output signal level from among the plurality of second output signal levels,

adjust the plurality of gains to compensate for a variation of the first output signal level, and

substantially maintain the plurality of second output signal levels above a threshold signal level.

11. The tuner system of claim 10, wherein the first amplifier comprises:

a first and a second differential amplifier; and

an attenuator, coupled between the first and the second differential amplifiers, configured to attenuate the input signal to provide an attenuated input signal,

wherein the first differential amplifier is configured to amplify the input signal, and

wherein the second differential amplifier is configured to amplify the attenuated input signal.

12. The tuner system of claim 11, wherein the gain control device is further configured to activate the first or the second differential amplifier to adjust a gain of the first amplifier.

13. The tuner system of claim 10, wherein the tuner system is coupled to a television tuner device, and

wherein the gain control device is further configured to provide automatic gain control across a frequency spectrum of the television tuner device.

14. The tuner system of claim 10, wherein a second amplifier from among the plurality of second amplifiers comprises:

a pair of differential amplifiers; and

a summing device configured to sum an output of the pair of differential amplifiers to provide a second output signal from among the plurality of second output signals.

15. The tuner system of claim 10, further comprising:

a power detector configured to detect a corresponding one of the plurality of second output signal levels that corresponds to the second output signal and to provide the corresponding one of the plurality of second output signal levels to the gain control device.

16. In a tuner system, a method comprising:

amplifying an input signal according to a plurality of gains to provide a plurality of output signals;

monitoring a signal level of an output signal from among the plurality of output signals; and

adjusting the plurality of gains to maintain signal levels of the plurality of the output signals at substantially similar signal levels.

17. The method according to claim 16, further comprising:

amplifying a received signal according to a second gain to provide the input signal.

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

adjusting the second gain to maintain the plurality of output signals at substantially similar signal levels.

19. The method according to claim 16, further comprising:

filtering the plurality of output signals to provide a plurality of tuned signals.

20. The method according to claim 19, further comprising:

demodulating the plurality of tuned signals to extract signal information.