Differential Attenuator Circuit for Wide-Range RF Power Handling
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Solution Overview
Problem
Existing RF attenuator circuits face challenges in providing a wide attenuation range with fine minimum attenuation steps while maintaining robustness against high RF input power, especially in multi-Gigabit wireless communication systems where low power consumption and accurate phase and amplitude control are crucial.
Innovation Solution
The proposed attenuator circuit employs a series of resistive elements and shunt paths with switch circuits that adjust on-state resistance based on control signals, allowing for digital control of attenuation across a wide range with minimal power consumption and high robustness, using semiconductor switches and resistors in parallel configurations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If traditional RF attenuator circuits are used, then they can provide signal attenuation, but they cannot provide a wide attenuation range with fine minimum attenuation steps while maintaining robustness against high RF input power
Solution Approach 1:
The attenuator circuit is divided into multiple independent attenuation stages, each with its own switch circuit and resistive elements. This segmentation allows each stage to handle a portion of the total attenuation range, enabling the overall circuit to achieve a wide attenuation range (0 dB to -25 dB) while maintaining robustness against high RF input power through distributed power handling.
Solution Approach 2:
The attenuator employs dynamically controllable switch circuits that can adjust the attenuation level in real-time based on control signals. The switch circuits enable dynamic selection of different attenuation states, providing fine minimum attenuation steps (1 dB) while maintaining the ability to withstand high RF input power through adaptive configuration.
2Use of energy by moving object
If Variable Gain Amplifiers (VGAs) are used instead of attenuators, then power consumption may be reduced, but DC power consumption increases and temperature dependence worsens
Solution Approach 1:
The patent replaces active VGA components with a passive attenuator circuit composed of resistive elements and switch circuits. This substitution eliminates the need for DC power consumption associated with active amplification while reducing temperature dependence through the use of passive components that are inherently more stable across temperature variations.
3Reliability
If attenuators are designed for high power handling capability, then they can withstand high RF input power, but device complexity increases
Solution Approach 1:
The high power handling capability is achieved through segmentation into multiple attenuation stages, where each stage handles a portion of the total power. This distributes the power handling burden across multiple simpler stages rather than requiring a single complex high-power component, thereby maintaining reliability while controlling overall device complexity.
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
This solution enables the attenuator circuit to offer a wide attenuation range (up to -25 dB) with a fine minimum step (1 dB) and withstand high RF input power (up to 20 dBm) with reduced power dissipation and increased reliability, suitable for modern wireless communication systems.
Implementation Method 1
switch circuits that adjust on-state resistance based on control signals
Implementation Method 2
series of resistive elements and shunt paths
Data Source
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AI summary
An attenuator circuit (200) is provided. The attenuator circuit includes a first input node (110) and a second input node (120) each configured to receive a respective one of a first input signal and a second input signal forming a differential input signal pair. Further, the attenuator circuit includes a first plurality of resistive elements (160-1,...160-6) coupled in series between the first input node (110) and a first output node (130) for outputting a first output signal. The attenuator circuit additionally includes a second plurality of resistive elements (150-1,...150-6) coupled in series between the second input node (120) and a second output (140) node for outputting a second output signal. In addition, the attenuator circuit includes a shunt path (170) coupled to a first intermediate node (115) and a second intermediate node (125). The first intermedia node is arranged between two resistive elements of the first plurality of resistive elements. The second intermedia node is arranged between two resistive elements of the second plurality of resistive elements. The shunt path comprises a switch circuit (180) configured to selectively couple the first intermediate node and the second intermediate node based on one or more control signals.