Three methods of measureing noise figure of LNA/Mixer

From the below link:
http://pdfserv.maxim-ic.com/en/an/AN2875.pdf


Summary


In this article, three methods to measure the noise figure of RF devices are discussed. They each have

advantages and disadvantages and each is suitable for certain applications. Below is a summary table of the pros

and cons. Theoretically, the measurement results of the same RF device should be identical, but due to

limitations of RF equipment (availability, accuracy, frequency range, noise floor, etc), we have to carefully

choose the best method to get the correct results.