A system to measure out-of-band noise of IEEE 802.11b/g/a/n/ac transmitter signals in cellular frequency bands with noise calibration

Abstract

This paper introduces a system to accurately measure conducted out-of-band (OOB) noise of IEEE 802.11b/g/a/n/ac transmitter signals in cellular frequencies with a spectrum analyzer. The low-level (<;160dBm/Hz) OOB noise measurement is usually limited by the dynamic range and the thermal noise of a spectrum analyzer. The proposed setup notches out transmitter signals, amplifies OOB noise and uses the noise calibration technique to detect noise power down to -169dBm with 99.73% confidence level for frequencies below 2.4GHz, and -167dBm for frequency from 2.5GHz-2.7GHz. The measured OOB noise is verified with a noise source and with less than <;0.5dB error.