.3 Mm Full-band High-precision Noise Standard Technology

Noise figure is the most important parameter of 3mm low noise figure IC and key device of receiving front end of equipment. Noise figure directly determines the performance of equipment. In noise figure measurement, the excess noise ratio(ENR) uncertainty of noise source is the main error source. But, there is no ability of calibration now in China. Therefore, it's necessary to study the calibration method of 3mm noise source. Through consulting the method of calibration in foreign countries and considering the practical need in our application, the unique project finally comes into being. The process brings into effect as follows. In this project, we use cold/hot noise sources as standard noise sources, use Noise Figure Analyzer(NFA) as intermediate frequency (IF) receiver and use frequency expansion device to down-convert 3mm noise signal to IF, so as to realize the calibration of 3mm noise source. Through selecting IF to implement the identical results of the double band and single band measurement to ensure the final right result; Through setting the appropriate attenuator of radio frequency(RF) & IF and using two head isolators to realize the linearity in the system measurement and endure the invariability of equivalent noise temperature(Te) in the system, we fulfill the precondition of the calibration principle; We select right mixture and average for data, three-dimensional flat roof to aim at standard cold/hot noise source and receiver and developing the switch device to improve stabilization of the system.The calibration system has wide frequency span (75GHz-110GHz) , it is reliable and easy to use , it has low measurement uncertainty .These can meet the calibration traceability need of 3mm noise source. Moreover, the result is novel in the technology search and is applied into a patent.