Test & Measurement
Diodes to check out the noise levels, with precision
Just announced by specialist UK distributor of test and measurement products, Aspen Electronics, is a range of noise diodes and modules designed specifically for analogue noise systems and associated built in test equipment (BITE).Conceived and manufactured in the US by Noisecom, a brand name of the Wireless Telecom Group, based in New Jersey, there are three series available. They are targeted at commercial and military communications industries where accurate, reliable noise measurements are essential.
All Noisecom noise diodes can deliver symmetrical white Gaussian noise and flat output power versus frequency. The diodes cover the frequency range from 0.1Hz to 110GHz, are hermetically sealed and available in a variety of packaging styles.
Typical wireless applications include testing of satellite communications equipment, cellular radio handsets, HDTV data links and 3G/4G digital wireless networks. In wired applications, the diodes are used in test equipment for high speed serial data links, and for testing signal to noise ratio performance in standards-based systems undergoing compliance checks, including PCIe, USB and even 10G/40G Ethernet and beyond.
The NC100/200/300/400 Series of noise diodes are the fundamental building blocks for analogue noise systems. They are characterised specifically to optimise their broadband noise output and flat spectral response features. The NC100 & 200 series are aimed at audio and RF applications, while the NC300 & 400 series are designed for microwave equipment.
For built in test equipment applications, Aspen recommends the NC500/500SM Series BITE Modules. These noise modules are an economical solution for applications including signal strength meters, calibrators, spectrum analysers, radar warning receivers, dither A/D quantisation error measurements and gain-bandwidth product testing.
They contain complete bias circuits and require no external components. The modules produce extremely flat output power versus frequency characteristic that is insensitive to temperature and voltage variations.
The NC500 Series modules are housed in a TO-8 metal can, while the NC500SM Series devices are packaged in a surface mount plastic package suitable for mounting on microstrip. Both typically require 5mA and produce a minimum of 31dB ENR of white Gaussian noise. The NC510 and 510SM models contain additional gain stages for higher power ENR output (51dB) and typically require15mA.
The NC2000/4000 Series are amplified noise modules ideal for higher performance, board-level noise systems. The NC2000 Series are housed in 24 or 14pin dual in line packages. The NC4000 series are housed in a 40pin module offering similar noise bands to the NC2000, but with a higher crest factor, and 60dB of TTL controlled attenuation.
Specific applications for these modules include dither circuitry for A/D converters, communications jamming equipment, PCI Express jitter applications and built-in test equipment
All products in the range are currently available in the UK from Aspen Electronics, with samples in stock and a delivery lead time of 8 weeks typical. Prices start and £10, depending on specification and all noise diodes and modules are RoHS compliant.