Multi-Input Amplifier Bypass Paths for Low-Noise High Gain
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Solution Overview
Problem
Existing amplifiers for wireless communication devices face challenges in maintaining desired signal characteristics across a range of gain levels, particularly in high gain modes where noise factor is increased and linearity is compromised due to the use of variable attenuation elements.
Innovation Solution
A variable-gain signal amplifier with a first attenuation stage having multiple branches with switches and programmable attenuation elements, allowing for a bypass path in high gain mode to prevent noise increase, and tailored attenuation in other modes to enhance linearity, coupled with an amplification stage and a post-amplification attenuation stage to maintain signal quality across various gain levels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If variable attenuation elements are used in high gain modes, then signal attenuation can be controlled, but noise factor increases and linearity is compromised
Solution Approach 1:
The amplifier is divided into multiple independent branches, each with its own attenuation element and switch. This segmentation allows selective activation of attenuation paths based on operating conditions, enabling the system to bypass attenuation elements in high gain modes to maintain low noise factor while still providing attenuation control capability when needed.
Solution Approach 2:
The amplifier employs dynamic switching between different gain modes and attenuation paths based on real-time operating conditions. The control circuit dynamically adjusts which branches are active and whether attenuation elements are engaged, allowing the system to adapt to varying signal levels and maintain optimal noise factor and linearity across different operating scenarios.
2Stability of the object's composition
If attenuation is applied to all input signals, then linearity is improved, but signal quality deteriorates in high gain modes due to noise increase
Solution Approach 1:
Different branches of the amplifier are configured with different attenuation characteristics tailored to specific input signal levels and frequency ranges. The control circuit selectively activates branches with appropriate attenuation levels based on the actual input signal conditions, applying attenuation locally where it benefits linearity while bypassing it in high gain modes where signal quality would deteriorate.
Solution Approach 2:
The amplifier dynamically changes operational parameters including attenuation levels, branch selection, and gain mode based on input signal characteristics. This parameter adaptation allows the system to optimize linearity when signals require attenuation while maintaining high signal quality in high gain modes by adjusting the attenuation parameters or bypassing them entirely.
3Adaptability or versatility
If multiple branches with attenuation elements are used, then signal processing flexibility is improved, but device complexity increases
Solution Approach 1:
Multiple branches share common components including the amplification stage, output circuitry, and control logic. Each branch is designed with similar structural elements (switch, attenuation element, amplifier connection) that can be selectively activated. This universal design provides signal processing flexibility across different operating conditions while minimizing overall device complexity through component sharing and modular architecture.
Data Source
AI summary
Described herein are variable gain amplifiers and multiplexers that embed programmable attenuators into switchable paths to provide variable gain for individual amplifier inputs. The variable gain for an individual input is provided using an amplification stage that is common for each input of the amplifier. A variable attenuation is provided for individual inputs through a combination of a band selection switch and an attenuation selection branch. Individual inputs can be configured to bypass the variable attenuation in a high gain mode.