Orthogonal Code-Based Transmitted Radiation Pattern Measurement Method for 5G Massive MIMO Antenna Systems

This article presents a novel method to measure the transmitted radiation pattern by using orthogonal encoded signals during the process of hybrid analog-digital (HAD) beamformer development. One of the most important indicators in evaluating the performance of HAD beamforming systems is the measurement of the sub-array radiation patterns. However, as the number of elements increases, the number of combinations that can create sub-arrays increases significantly, and the conventional radiation pattern measurement process becomes exhaustive. However, when an orthogonal coded signal is used for the HAD beamforming system measurement, the magnitude and phase information of each element of the HAD beamforming system, including mutual coupling, can be simultaneously obtained from a single scan. Hence, it is possible to measure all feasible sub-array patterns very efficiently. Therefore, we propose an orthogonal code-based time-domain measurement technique and validate it with full-wave time-domain simulations. The results show that it is possible to receive element pattern information independently and that any sub-array pattern can be reconstructed with an accuracy greater than 99.99%.