Transistor On-Resistance Attenuator for Wide Linear Gain Control
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Solution Overview
Problem
Existing electronic circuits for controlling signal gain in RF applications have limited linearity and a narrow gain control range, which restricts their effectiveness in signal processing and transmission.
Innovation Solution
An electronic circuit design incorporating a path unit and a shunt unit that utilize the on-resistance of transistors to form impedance for gain control, with a plurality of paths and a reverse-bias state for transistors to enhance linearity and attenuation capabilities, including an attenuation enabling unit to selectively connect these units for precise gain management.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional attenuator circuits are used for gain control, then the circuit can perform basic signal attenuation, but the gain control range is limited and linearity is poor
Solution Approach 1:
The attenuator is divided into multiple independent attenuation units, each capable of providing a specific attenuation amount. By selectively enabling or disabling these units through control signals, the circuit achieves both a wide gain control range and maintains linearity within each segment. This segmentation allows the system to cover a broad dynamic range while preserving signal integrity in each operational band.
2Adaptability or versatility
If the attenuator gain control range is increased, then more signal levels can be controlled, but the linearity deteriorates
Solution Approach 1:
The attenuator employs dynamic control mechanisms where multiple attenuation units are selectively activated based on the desired attenuation level. Each unit is designed with specific characteristics to maintain linearity within its operational range, and the control logic dynamically switches between units to achieve the required gain control range while preserving linearity. This dynamic approach allows the system to adapt to different signal levels without sacrificing linearity.
3Area of stationary object
If transistors are used to form impedance for gain control, then the circuit size is reduced and PVT variation is minimized, but the circuit complexity increases
Solution Approach 1:
The transistor-based impedance forming structure serves multiple functions simultaneously: it provides the necessary impedance for gain control, acts as a switchable element for selective attenuation, and contributes to overall circuit integration. By making the transistor serve multiple purposes, the design reduces the need for separate dedicated components, thereby minimizing circuit size and PVT variation while the modular organization of attenuation units keeps the complexity manageable.
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 provides a wide gain control range with high linearity, minimizing circuit size and temperature variations, thereby improving signal processing and transmission efficiency.
Implementation Method 1
the path unit may form the first impedance using an on-resistance of at least one transistor
Implementation Method 2
the input matching unit may include at least one inductor for performing compensation associated with a parasitic capacitance of the at least one transistor
Data Source
AI summary
An apparatus including an electronic circuit. The apparatus includes a path unit configured to form a first impedance for controlling a gain of an input signal. The apparatus also includes a shunt unit configured to form a second impedance for performing attenuation between the path unit and a ground, wherein the path unit forms the first impedance using an on-resistance of at least one transistor.