Voltage-Controlled RF Attenuator With Reduced Distortion and Insertion Loss
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Solution Overview
Problem
Existing RF attenuators introduce distortion and insertion loss when reducing signal amplitude, which can be amplified by gain circuitry and reflected in the final output of RF devices, making it challenging to attenuate signals without distorting waveform characteristics.
Innovation Solution
A voltage-controlled variable attenuator using transistors and resistive components is configured to minimize insertion loss during minimum attenuation periods, with transistors having open and closed configurations to control current flow and resistive components mitigating non-linear effects, allowing for continuous signal attenuation without discrete steps.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If RF attenuators are used to reduce signal amplitude, then signal power is reduced, but distortion and insertion loss are introduced
Solution Approach 1:
The patent employs transistors that can dynamically switch between open and closed configurations based on control signals. This dynamic operation allows the attenuator to adapt its attenuation level while minimizing distortion and insertion loss by only introducing components when needed, rather than having fixed attenuators always present in the signal path.
Solution Approach 2:
The invention changes the operational parameters of the transistor by applying control voltages to transition between open and closed configurations. This parameter change enables continuous variable attenuation while maintaining signal integrity, as the transistor's resistance characteristics are dynamically adjusted rather than fixed.
2Adaptability or versatility
If transistors are used for variable attenuation, then continuous attenuation control is achieved, but non-linear effects are introduced during transition
Solution Approach 1:
The patent introduces resistive components as intermediary elements that work in conjunction with the transistor. These resistive components help linearize the transistor's operation during transitions between open and closed configurations, mitigating non-linear effects while preserving the variable attenuation capability.
Solution Approach 2:
The invention creates a composite structure combining transistor elements with resistive components. This composite approach leverages the variable control characteristics of the transistor while the resistive elements provide linearizing effects, achieving both adaptability and reduced non-linear distortion.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution effectively reduces signal amplitude while minimizing insertion loss and distortion, ensuring that the signal is transmitted with minimal noise and maintaining waveform integrity, even during periods of low attenuation.
Implementation Method 1
The transistor has an open configuration for at least substantially preventing the flow of current through the transistor, and a closed configuration for at least partially allowing the flow of current through the transistor
Implementation Method 2
The resistive component is configured to at least partially mitigate non-linear effect when the transistor transitions from the open configuration to the closed configuration
Data Source
AI summary
Voltage controlled variable attenuators are described that are configured to be coupled to a transmission path to furnish variable attenuation of a signal, such as a radio frequency signal. In one or more implementations, the voltage controlled variable attenuator includes at least one transistor. The transistor has an open configuration for at least substantially preventing the flow of current through the transistor, and a closed configuration for at least partially allowing the flow of current through the transistor. The variable attenuator also includes a resistive component coupled to the transistor, and configured to couple to the transmission path. The resistive component is configured to at least partially mitigate non-linear effect when the transistor transitions from the open configuration to the closed configuration. The transistor and the resistive component are configured to at least partially attenuate a signal transmitted along the transmission path when the transistor is in the closed configuration.