罗德与施瓦茨 FSW-K575 IQ 噪声抵消选件用途：适用于 Wi-Fi 7 等对 EVM（误差向量幅度）性能要求极高的通信系统测试场景。尤其是在 WLAN 芯片研发等领域，可帮助研发工程师在测试时消除噪声干扰，提升测试的动态范围，为射频链路预留足够余量。性能：该选件集成于仪器固件中的算法，通过在接收端处理信号，消除 IQ 不平衡和噪声干扰。具体做法是多次测量接收信号噪声，与接收机功率测量及输入端口负载情况对比，获取接收机内部噪声；多次测量取平均后与参考信号比较，估计出接近理想的无噪声信号；对多次测量结果与该平均值做修正运算，从而得到外部引入的噪声。以 6GHz、320MHz 带宽、4096QAM 调制方式的 Wi-Fi 7 信号为例，开启 20 次平均后，EVM 可从低于 - 50dB 提升至 - 54dB，能有效应对外部嘈杂噪声的 OTA 环境或路径损耗较大的测试场景 。

Product Name: Rohde & Schwarz FSW-K575 IQ Noise Cancellation OptionPurpose: It is suitable for test scenarios of communication systems with extremely high requirements for EVM (Error Vector Magnitude) performance, such as Wi-Fi 7. Especially in fields like WLAN chip research and development, it can assist R & D engineers in eliminating noise interference during testing, improving the dynamic range of testing, and reserving sufficient margin for the RF link.Performance: This option integrates an algorithm in the instrument's firmware to process signals at the receiving end, eliminating IQ imbalance and noise interference. Specifically, it measures the received signal noise multiple times, compares it with the receiver power measurement and input port load conditions to obtain the internal noise of the receiver. After taking the average of multiple measurements and comparing it with the reference signal, it estimates a nearly ideal noise-free signal. Then, it performs a correction operation on the multiple measurement results and this average value to obtain the externally introduced noise. Taking a Wi-Fi 7 signal with 6GHz, 320MHz bandwidth, and 4096QAM modulation as an example, after enabling 20 times of averaging, the EVM can be improved from less than -50dB to -54dB, effectively coping with OTA environments with external noisy interference or test scenarios with large path losses.