The Implementation Margin of a satellite communication system is defined as the degradation of the signal after travelling through the up and downlink equipment. In order to find this, an EbNo generator such as the Noisecom CNG-EbNo Series can first be used to carry out an IF loopback test of the modem in order to find bit error rate (BER) values at different Eb/No ratios. A plot of these values can then be compared with the theoretical curve for the digital modulation scheme being used. The resultant difference is termed the implementation loss of the modem, and this value is used as a reference level for the second part of the test, in which the implementation margin of the complete up and downlink is found.
In the quest to produce Low Noise Amplifiers (LNAs) with the lowest possible noise figures it is common to employ cryogenic techniques to cool the LNA to 20o kelvins (-253o C) or even lower. This has multiple beneficial effects: the minimum noise figure and noise resistance of the low noise transistors in the LNA are both substantially reduced, but also any ohmic losses in the LNA contribute far less thermal noise and indeed the losses themselves are usually substantially reduced as the conductivity of metals generally increases considerably at these low temperatures.
What Is Noise? All materials produce noise at a power level proportional to the physical temperature of the material. Chinese application note available.
Learn all you need to know about what noise can do, how it is created, types of noise Noisecom provides and how to control it. It is a great resource to define your noise requirements and identify what Noisecom product or products you can use: component, module or instrument. Chinese application note available.
This document provides Noisecom's method of measuring crest factor of a noise source using a LeCroy Wavepro 7200 Oscilloscope. Chinese application note available.
The radiometer is a sensitive, accurate, calibrated receiver that is used for remote measurement of temperature. Chinese application note available.
A simple way to calibrate a spectrum analyzer is to use a broadband white noise source to monitor the analyzer's frequency response. Chinese application note available.