## 1 Introduction  
As the number of automotive antennas and related wireless protocols increases, the functionality of modern vehicles' communication subsystems resembles that of traditional mobile user devices. Therefore, there is a growing demand for the expansion of automotive antenna measurement systems, leading to the need for mature OTA testing facilities. These testing systems typically require SNF data for a hemisphere surrounding the vehicle. The vehicle is placed on a turntable and rotated, while a rotating gantry or a fixed arch with a movable probe or probe array collects amplitude and phase data and converts them into far-field measurements. The large electrical size of these vehicles, coupled with the lack of formal OTA standards in the automotive industry, makes the design of such systems quite challenging [1, 2]. Currently, common testing methods include multiprobe [3] and two-stage testing methods [4]. In the multiprobe testing method, multiple downlink signals output from a base station simulator first enter a channel emulator during the testing process. The channel emulator applies fading to the downlink signals from the base station simulator according to the channel scenario configured in the system, calculating the incident angles, power delays, angular spreads, and polarization directions of the multipath downlink signals around the terminal after fading based on the specified channel model. Signals with different incident angles are then mapped to the corresponding probes in the anechoic chamber. Multiple probes in the anechoic chamber transmit simultaneously based on the loaded results from the channel emulator, thus simulating downlink signals with different arrival angles, powers, polarizations, and delay characteristics in the testing area. Generally, testing systems require the configuration of multichannel amplifiers to amplify the downlink signals reaching the multiple probes, ensuring that the downlink power in the testing area maintains a stable and reliable connection. The first phase of the two-stage method is to obtain the antenna radiation pattern; the near-field radiation pattern of the entire vehicle antenna is measured in an anechoic chamber and transformed into the far-field radiation pattern, representing the radiation pattern of the DUT. The second phase involves loading the radiation pattern information measured in the first phase into the channel emulator to simulate a wireless channel that includes the characteristics of the DUT antenna. The downlink signals output by the base station simulator are convolved with the wireless channel that has the DUT direction pattern information loaded and then emitted via the measurement antenna for receiver performance testing. On 12 June 2024, the Global Automotive Information Communication Evaluation Technology Innovation Base, funded by China Automotive Research in Chongqing with a total investment of nearly 350 million yuan, implemented a testing method to evaluate the performance of wireless communication terminal antennas. This method simulated the transmission scenario of product wireless signals in the air, comprehensively validating the impact of various factors on overall performance from the chip to the antenna end. The laboratory adopted the most widely accepted whole-vehicle spherical near-field testing scheme in the industry, meeting testing requirements for passive and active performance of antennas related to cellular communication, positioning, short-range communication, and C-V2X. This also established industry-leading capabilities for automotive communication research and development testing services [5]. Currently, automotive communication testing continues to rely on methods utilizing small-scale electrical components. Traditional testing approaches are not only complex in their procedure, but also often entail substantial cost investments.