Over-the-Air System Noise Temperature Measurement of Active Integrated Antennas in a Reverberation Chamber

Abstract

Low noise receivers play an essential role in wireless systems in radio astronomy and 5G/6G applications. Especially in radioastronomy, the received signal strength is very weak. Therefore, maintaining a good Signal-to-Noise Ratio (SNR) is quite important. A known concept to reduce the system noise temperature is to use noise matching for the Low-Noise Amplifier (LNA) and the antenna to get the optimal SNR. Due to the integrated nature of these systems, it is challenging to measure the noise performance of the total system accurately. For example, existing methods such as the Radiometric or the G/T method can be sensitive to inaccuracies due to the dependency on the sky noise temperature, the radiation pattern of the antenna, or the size of the antenna [1, 2]. Therefore we developed a new method, which can estimate the Noise Figure (NF) of a wireless system over-the-air (OTA), independent of these factors. The new method uses the Reverberation Chamber (RC) to create a consistent and repeatable environment. The uniform behavior of the RC makes the method independent of the radiation pattern of the antenna. This method measures the integrated antenna as one system, so the efficiency of the antenna, the NF of the LNA, and the noise matching between the Antenna and LNA are all taken into account.