Semiconductor Device Analog Signal Processing for Sound Source Identification
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Increasing the number of microphones in sound-source identification systems leads to exponential processing time and malfunctions due to frequency differences and unsynchronization in signal processing, reducing angular resolution.
Innovation Solution
A semiconductor device with a microphone array and signal processing circuit that collectively processes analog signals from multiple microphones using oxide semiconductor transistors, reducing the need for A/D converters and minimizing malfunctions caused by frequency differences and unsynchronization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the number of microphones is increased for angular resolution, then measurement precision is improved, but processing time increases exponentially
Solution Approach 1:
The patent replaces digital signal processing (arithmetic operations) with analog signal processing (electrical circuit operations). By using operational amplifiers and resistors to perform delay and summation operations in the analog domain, the system avoids the exponential processing time increase that would occur with digital methods for multiple microphones, while maintaining angular resolution measurement precision
2Measurement precision
If A/D converter circuits are provided individually to each microphone, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent merges the signal conversion function into a single shared A/D converter that processes signals after analog delay-and-sum operations are performed on all microphone inputs. This eliminates the need for individual A/D converters for each microphone, reducing device complexity while maintaining measurement precision through the unified processing approach
3Measurement precision
If plenty of arithmetic processing is performed for signal delay, then measurement precision is improved, but reliability decreases due to frequency differences and unsynchronization
Solution Approach 1:
The patent substitutes arithmetic delay operations with analog electrical delay circuits that use operational amplifiers and resistors. This analog approach processes all microphone signals simultaneously in the electrical domain, eliminating frequency differences and synchronization issues that arise from sequential digital arithmetic operations, thereby improving reliability while maintaining sound-source location accuracy
Data Source
AI summary
A semiconductor device with a novel structure which can identify the sound source is provided. The semiconductor device includes a microphone array, delay circuits, and a signal processing circuit. The delay circuit includes a first selection circuit, which selects a microphone, signal retention circuits, which retain voltages depending on the sound signal, and a second selection circuit, which selects a signal retention circuit. Each signal retention circuit includes a transistor which includes a semiconductor layer including an oxide semiconductor in its channel formation region. The first selection circuit writes the voltage of discreet sound signals to the signal retention circuit. The second selection circuit selects at different timings the voltages which are retained in the signal retention circuit and generates the output signal corresponding to the delayed sound signal.