MOSFET Switch Control in Amplifiers for Parasitic Capacitance

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Solution Overview

Problem

In 5G mobile communication systems using the mmWave band, the performance of amplifiers is reduced due to parasitic capacitance components caused by metal-oxide-semiconductor field-effect transistors (MOSFETs), leading to reduced gain and bandwidth.

Innovation Solution

The amplifier structure incorporates a switch control processor that connects the gate and bulk terminals of the MOSFETs to impedances with high impedance values, preventing current flow through parasitic capacitances and maintaining amplifier performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If an amplifier is designed to be compact and inexpensive, then it can be mass-produced and widely used, but it cannot provide sufficient bass output and dynamic range

Engineering Contradiction:
Improvemass production capabilityVSAvoidbass output and dynamic range
Core Design Contradiction:
ProductivityVSPower

Solution Approach 1:

The audio signal processing is divided into multiple frequency bands (e.g., bass, midrange, treble) that are handled separately by individual amplification channels. This allows each channel to be optimized for its specific frequency range, enabling compact amplifiers to deliver sufficient bass output by dedicating specific amplification resources to low-frequency signals without requiring a single high-power amplifier to handle all frequencies.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system dynamically adjusts amplification parameters (gain, bandwidth, impedance) based on the input signal characteristics and operating conditions. By changing these parameters adaptively, the amplifier can maximize bass output and dynamic range within the constraints of compact design, allowing the same hardware to deliver different performance levels for different signal types.

Inventive Principle:
Principle #35Parameter changes

2Device complexity

If a single amplifier channel is used to handle all frequency ranges, then the device complexity is reduced, but the amplifier cannot deliver sufficient dynamic range and bass output

Engineering Contradiction:
Improveamplifier channel configurationVSAvoiddynamic range
Core Design Contradiction:
Device complexityVSPower

Solution Approach 1:

Multiple amplification channels are designed with universal control and processing capabilities that can be dynamically allocated to different frequency ranges as needed. Rather than having dedicated fixed-function amplifiers for each band, the system uses universally capable channels that can be configured through software or control circuits to handle bass, midrange, or treble signals, reducing hardware complexity while maintaining the dynamic range benefits of multi-band processing.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Power

If high-power amplification is provided for all frequency ranges, then sufficient bass and dynamic range are achieved, but power consumption increases and compact design becomes difficult

Engineering Contradiction:
Improvebass output capabilityVSAvoidpower consumption
Core Design Contradiction:
PowerVSUse of energy by moving object

Solution Approach 1:

The amplifier system activates high-power amplification only periodically or on-demand for specific frequency bands when bass content is detected in the input signal, rather than maintaining high power levels continuously for all channels. This allows compact amplifiers to deliver sufficient bass output when needed while minimizing power consumption during normal operation, achieving a balance between performance and energy efficiency.

Inventive Principle:
Principle #19Periodic action

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 effectively prevents the reduction of amplifier gain and bandwidth due to parasitic capacitance, ensuring improved performance even in high-frequency ranges.

Implementation Method 1

the performance (e.g., gain or bandwidth) of the amplifier may be reduced due to parasitic capacitance components caused by the MOSFETs

Methodology Applied
Scientific EffectParasitic capacitance: Parasitic Capacitance

Data Source

PatentEP3861634B1Amplifier having switch and switch control processor controlling switch
Publication Date: 2025.03.05 SAMSUNG ELECTRONICS CO LTD
  • EP3861634B1 patent drawingFigure 1a~1b
  • EP3861634B1 patent drawingFigure 2a
  • EP3861634B1 patent drawingFigure 2b

AI summary

The present disclosure relates to a pre-5th-Generation (5G) or 5G communication system to be provided for supporting higher data rates Beyond 4th-Generation (4G) communication system such as Long Term Evolution (LTE). An amplifier is provided. The amplifier includes a first resistor electrically connected to the input terminal, a second resistor electrically connected to the output terminal, a switch including a metal-oxide-semiconductor field-effect transistor (MOSFET) and electrically connected to one end of the second resistor, and a switch control processor configured to electrically connect the gate terminal of the MOSFET constituting the switch and the bulk terminal of the MOSFET constituting the switch to an impedance having an impedance value higher than a preset first threshold.