MOS Mixer Circuit Using Load Transistors to Cut Nonlinearity
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Solution Overview
Problem
Conventional mixing circuits face challenges in reducing non-linear components while minimizing power consumption, as increasing the gate-source voltage to decrease non-linear components leads to higher consumption current.
Innovation Solution
The mixing circuit incorporates load MOS transistors as resistance elements, allowing for reduced non-linearity without increasing the gate-source voltage, and utilizes identical MOS transistors and variable resistance elements to achieve this reduction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the gate-source voltage is increased to decrease non-linear components, then the non-linear component is reduced, but the consumption current increases
Solution Approach 1:
The invention changes the circuit configuration parameters by replacing conventional resistance elements with MOS transistors operating in specific regions. This allows achieving low non-linear components through transistor characteristics rather than voltage scaling, thus reducing consumption current while maintaining signal linearity.
Solution Approach 2:
The invention introduces MOS transistors as intermediary elements between the signal path and ground, using their controlled resistance characteristics to achieve linearization. These transistors act as active resistance elements that provide the necessary impedance matching and signal conditioning without requiring high gate-source voltages.
2Device complexity
If conventional resistance elements are used, then the circuit structure is simple, but the non-linear component increases
Solution Approach 1:
The invention substitutes passive resistance elements with active MOS transistor-based impedance matching circuits. This replacement enables dynamic control of resistance values and provides better linearity through the transistor's voltage-controlled characteristics, achieving superior performance despite increased circuit complexity.
Solution Approach 2:
The invention creates a composite circuit structure combining MOS transistors with resistance elements to form an impedance matching circuit. This composite approach leverages the advantages of both active and passive components, achieving low non-linear components while maintaining reasonable circuit complexity.
Data Source
AI summary
There is provided a mixing circuit in which a rise of the consumption current can be suppressed while decreasing a non-linear component. The mixing circuit includes: an input unit 803 including a grounded-gate MOS transistor M1 with a source into which an input signal is input, and a grounded-source MOS transistor M2 with a gate into which the input signal is input; a frequency converter 802 for converting frequencies of a first current signal output from the grounded-gate MOS transistor M1 and a second current signal output from the grounded-source MOS transistor M2, and for generating a third current signal and a fourth current signal; a load MOS transistor M7, with a gate and a drain connected, for receiving a third current signal; and a load MOS transistor M8, with a gate and a drain connected, for receiving a fourth current signal.