Series Condenser Microphone Circuit for Higher Sensitivity

Solution Overview

Problem

Conventional condenser microphones with multiple units connected in series using active element impedance converters result in complex circuit structures, high costs, and limited dynamic range due to the need for multiple impedance converters and power supply management.

Innovation Solution

Directly connecting preceding condenser microphone units to the succeeding ones, except for the last unit, where an impedance converter using an active element is connected to add and output audio signals in phase, simplifying the circuit configuration and eliminating the need for intermediate impedance converters.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If multiple impedance converters using active elements are used for each condenser microphone unit, then output sensitivity can be improved, but circuit complexity and cost increase

Engineering Contradiction:

Improveoutput sensitivityVSAvoidcircuit complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

Multiple condenser microphone units are electrically connected in series to form a single integrated sensing element. The diaphragm of one unit connects to the fixed electrode of the next unit, creating a cascaded capacitance network that sums the output signals of all units through a single impedance converter, eliminating the need for multiple separate impedance conversion circuits

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

A single impedance converter serves multiple functions by converting the combined output signal from multiple condenser microphone units. This universal approach maintains the signal summation capability while reducing the number of active components and simplifying the overall circuit architecture

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Measurement precision

If multiple impedance converters are used for each condenser microphone unit, then output sensitivity can be improved, but manufacturing cost increases

Engineering Contradiction:

Improveoutput sensitivityVSAvoidmanufacturing cost

Core Design Contradiction:

Measurement precisionVSEase of manufacture

Solution Approach 1:

Multiple condenser microphone units are electrically connected in series to form a single integrated sensing element. The diaphragm of one unit connects to the fixed electrode of the next unit, creating a cascaded capacitance network that sums the output signals of all units through a single impedance converter, eliminating the need for multiple separate impedance conversion circuits

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent uses multiple identical or similar condenser microphone units with the same basic structure (diaphragm and fixed electrode), which can be manufactured using standardized processes. By connecting these replicated units in series rather than requiring complex individual impedance converters for each, manufacturing costs are reduced while maintaining enhanced output sensitivity

Inventive Principle:

Principle #26Copying

3Measurement precision

If multiple impedance converters with active elements are used, then output sensitivity can be improved, but power supply management becomes complex and dynamic range is limited

Engineering Contradiction:

Improveoutput sensitivityVSAvoidpower supply management

Core Design Contradiction:

Measurement precisionVSUse of energy by moving object

Solution Approach 1:

Multiple condenser microphone units are electrically connected in series to form a single integrated sensing element. The diaphragm of one unit connects to the fixed electrode of the next unit, creating a cascaded capacitance network that sums the output signals of all units through a single impedance converter, eliminating the need for multiple separate impedance conversion circuits

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The active impedance conversion function is extracted from multiple separate circuits and consolidated into a single impedance converter circuit. This extraction removes the need for multiple power supplies and active elements, simplifying power management while preserving the signal amplification and impedance matching functions

Inventive Principle:

Principle #2Taking out (Extraction)

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 configuration enhances output sensitivity while simplifying the circuit and reducing power supply issues, leading to improved dynamic range and cost-effectiveness compared to conventional designs.

Implementation Method 1

A condenser microphone generates an audio signal based on a change in capacitance between a diaphragm and a fixed electrode which are opposed to each other

Methodology Applied

Scientific EffectCapacitance: Capacitance

Data Source

PatentUS9521492B2Condenser microphone

Publication Date: 2016.12.13 AUDIO TECHNICA CORP

AI summary

Provided is a condenser microphone having a plurality of condenser microphone units connected in series to improve output sensitivity, and a simplified circuit configuration. At least one of the preceding condenser microphone units, excepting a last condenser microphone unit, and an adjacent succeeding condenser microphone unit are directly connected to transmit an audio signal obtained from the at least one of the preceding condenser microphone units to the adjacent succeeding condenser microphone unit. An impedance converter using an active element is connected to the last condenser microphone unit, and the audio signals obtained from the condenser microphone units are added and output from the impedance converter using the active element.