Test & Measurement

Using PXI to Build a High-Performance MEMS Microphone Testing System

The demand for increasing microphone signal quality from handheld mobile devices has led to the development of microphone signal processing technologies such as: HD audio, noise cancellation, active noise cancellation, beam forming, directional reception, stereo sound field reconstruction, and speech recognition. As well, devices incorporating multiple microphones are becoming more and more popular. Several newly released smart phones now integrate multiple MEMS (Micro Electrical-Mechanical System) microphones for improved background noise cancellation. All flagship smart phone models in introduced in 2015 featured three or more MEMS microphones to support HD audio, ambient noise cancellation, noise filtering, directional reception and speech recognition. Popularity of MEMS microphones is expected to grow.

Posted in: White Papers, Electronics, Data Acquisition, Sensors, Test & Measurement


A Brief History of Modern Digital Shaker Controllers

Over a period of 40 years, four generations of digital vibration exciter control systems have been developed by various companies in the USA. They are categorized as standalone, PC-based, PC-tethered, and fully networked. This paper discusses the evolution and improvement of shaker controllers and the critical parameters that users should consider during the acquisition process.

Posted in: White Papers, Test & Measurement


Force Transfer Machines

There has been ongoing debate as to whether or not a hydraulic force machine that applies the force simultaneously to both the reference standard and the unit under test is more repeatable and reproducible when the force is applied and transferred with 3 bars versus 2 bars. The debate centers around alignment of the reference standard and the unit under test. There is no disagreement about the benefits of using a triangular configuration when using multiple load cells to weigh an object; however, there is a debate over any advantages that might be offered by using a 3 bar Universal Calibrating Machine (UCM) instead of a traditional 2 bar system. This paper provides test results for repeatability and reproducibility for a 2 bar UCM and a 3 bar UCM, showing the null hypothesis to be correct and proving that there is not a difference between either type of UCM.

Posted in: White Papers, Instrumentation, Mechanical Components, Test & Measurement


Full RF Signal Chains from 0 Hz to 110 GHz

Analog Devices (ADI) has expanded its RF capabilities in the full signal chain, including companion products, in the full bandwidth from 0 Hz to 110 GHz.This white paper provides examples of the wider frequency spectrum covered by ADI, and explains that true DC is important. Off signal chain performance is also critical, and this paper shows how low-noise, high-stability control and power components are important to overall RF signal performance.

Posted in: White Papers, Electronics, Semiconductors & ICs, Data Acquisition, Sensors, Test & Measurement


Computer Aided Design of Suspension Mechanisms

Automobile suspension mechanisms have to date been designed using two-dimensional graphic oriented methods. Computer-aided design has allowed many two-dimensional mechanisms to be designed much more accurately. However, this has not translated to suspension mechanisms because these mechanisms are not two-dimensional but instead three-dimensional.

Posted in: White Papers, Electronics & Computers, Manufacturing & Prototyping, Software, Test & Measurement


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