Programmable Low-Noise Amplifier for Gain and Noise Control

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Solution Overview

Problem

Conventional wireless communication systems face limitations in gain control and noise management due to fixed amplifier configurations, which affect the quality of received signals and power efficiency.

Innovation Solution

A programmable low noise amplifier is introduced, comprising a programmable input stage, cascode stage, and resistor stage, allowing for adjustable gains and resonant tank circuit quality control via control signals, enabling flexible gain settings and reduced noise degradation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a fixed amplifier configuration is used, then the device complexity is reduced, but the adaptability and noise management capability deteriorate

Engineering Contradiction:
Improvegain control flexibilityVSAvoidamplifier configuration complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The amplifier configuration transitions from fixed to dynamically adjustable through multiple switchable gain stages. The first gain stage includes parallel transistor branches controlled by switches, allowing dynamic gain adjustment. The second gain stage similarly provides programmable gain control, enabling the amplifier to adapt to different signal conditions while maintaining a relatively simple base architecture.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The amplifier utilizes programmable gain control by changing the effective resistance and transconductance parameters through switchable transistor configurations. The gain stages can be programmed to different states, allowing the amplifier to optimize its performance for various signal levels and noise conditions without requiring completely different circuit topologies.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If higher gain is used to improve receiver sensitivity, then the signal detection capability is improved, but the noise degradation increases

Engineering Contradiction:
Improvereceiver sensitivityVSAvoidnoise degradation
Core Design Contradiction:
Measurement precisionVSObject-generated harmful factors

Solution Approach 1:

The amplifier is divided into multiple gain stages with independent control. The first gain stage provides initial signal amplification with low noise, while the second gain stage provides additional programmable gain. This segmentation allows the system to achieve high overall gain while managing noise accumulation by optimizing each stage's contribution to the total gain and noise figure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The amplifier incorporates noise figure feedback mechanisms where the noise performance of each stage is monitored and used to adjust the gain distribution. By measuring the actual noise contribution and adjusting the programmable gain settings accordingly, the system optimizes the balance between sensitivity and noise degradation in real-time operating conditions.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP2587667B1Programmable low noise amplifier and methods for use therewith
Publication Date: 2014.09.10 BROADCOM INC
  • EP2587667B1 patent drawingFigure 1
  • EP2587667B1 patent drawingFigure 2
  • EP2587667B1 patent drawingFigure 3

AI summary

A low noise amplifier includes a programmable input stage, having a first gain that is programmable based on a first control signal. A programmable cascode stage, has a second gain that is programmable based on a second control signal. A programmable resistor stage controls the quality of a resonant tank circuit, based on a third control signal.