Digital Calibration Filter for MEMS Sensor Frequency Response

The patent replaces complex analog circuitry measures with a digital signal processing approach. A digital calibration filter device processes the sensor output signal digitally, using filter coefficients stored in memory to compensate for frequency response variations. This substitution of digital processing for analog circuitry reduces device complexity while maintaining frequency response stability.

The patent changes the operating parameters of a digital filter (specifically the filter coefficients) to compensate for temperature-dependent frequency response variations. By storing multiple sets of filter coefficients corresponding to different temperature ranges and selecting the appropriate set based on the current temperature, the system maintains stable frequency response without requiring complex circuitry.

The patent performs calibration measurements and determines optimal filter coefficients in advance during the manufacturing process. These pre-determined filter coefficients are stored in memory within the device. During operation, the device simply retrieves and applies the appropriate pre-calibrated coefficients based on temperature, avoiding the need for complex real-time calibration processing while achieving high manufacturing precision.

The patent uses a simple digital filter structure with stored coefficients rather than complex adaptive filtering algorithms. The filter coefficients are predetermined and stored in memory, requiring only basic digital processing operations. This approach achieves precise frequency response calibration using simple, low-cost digital processing elements rather than sophisticated real-time adaptive systems.