Development and Validation of Hybrid SISO and MIMO OTA Testing Systems in Multiprobe Anechoic Chamber Setups

The multiprobe anechoic chamber (MPAC) is recognized for its ability to emulate various communication scenarios accurately. Traditional MPAC systems, however, often require separate setups for single-input single-output (SISO) and multiple-input multiple-output (MIMO) over-the-air (OTA) testing, leading to high costs and inefficiency. To address this issue, we have designed a low-cost, high-efficiency MPAC system that is compatible with SISO, 2-D, and 3-D MIMO testing. First, our innovative design integrates a vertical probe ring and a 3-D horizontal probe ring, enabling the MPAC system to support SISO, 2-D, and 3-D MIMO OTA testing. The layout of the probe rings is optimized to minimize reflections between antennas, thus improving testing accuracy. Additionally, based on the testing requirements for various devices, we designed and optimized the MPAC OTA testing system’s link, guiding the selection of key components such as amplifiers, switches, and cables, which endows the MPAC system with a greater dynamic range and compatibility with more devices. Furthermore, we improved the traditional complicated and time-consuming calibration procedures by proposing rapid calibration schemes for both SISO and MIMO OTA testing systems. With a laser positioning system and normalization calibration method employed, the calibration time is reduced from 1 to 2 days to within 10 min. Finally, we conducted quiet zone ripple testing, SISO total radiated power (TRP) and total isotropic sensitivity (TIS) testing validation, and MIMO channel model testing validation. These tests demonstrated the effectiveness and accuracy of the designed MPAC system in supporting SISO, 2-D, and 3-D MIMO OTA testing.