RF Characterization of WLAN

Abstract

Nowadays, the requirement of WLAN (wireless local area network) is increasing constantly. Verification of WLAN chip with front end module is becoming a crucial factor. So WLAN chip has to made which satisfying the FCC (Federal Communi- cations Commission) specification, good EVM, sensitivity, Noise Figure as well as it should work with low power. RF Characterization of front end supports various tests. These tests can be di- vided in two parts: Transmitter tests and Receiver tests. Some of the Transmitter tests are Transmit Signal Strength Indicator, Error Vector Magnitude, IM3, Phase Noise, PSAT, Harmonic Distortion, Out of Band Transmission, etc. At receiver side, tests like Sensitivity, Jammers, IIP2 and IIP3 measurements, Noise Figure are required. Spur reduction is done using load pull where we have trade of between power and spur level. One can not achieve both at a time. Algorithm is developed which will tuned the PAPD (Power Amplifier Pre-Distortion) parameters. For any change in external attenuation, algorithm will automatically tune the PAPD param- eters sach a way it will give good EVM and RX path should also in linear region. Sensitivity of receiver is checked in presence of jammer signals at 3 dB de-sence i.e Jammer power which degrades the sensitivity by 3 dB. Jammer signal can be LTE , BT or of any other standard. Worst case jammer numbers are founded by giving concentrated energy. How the jammer signal is degarding the desire signal is observed here.