Invited Talk: Xiong Chen, Tianjing University

Special session 1: EMC and OTA Testing for the Next Generation Communication Devices

Short Bio: 
Xiong Chen received his Ph.D. degree in electrical engineering from Xi’an Jiaotong University in 2018, and then joined Tianjin University, China, as assistant Professor in 2019. From 2017 to 2018, he visits the EMC Lab of Missouri S&T for high power EMC/EMI related researches. Since 2020, he has served as the group secretary for the IEEE proposal standard of P2717, Advanced Passive Intermodulation Test and System in Low Noise Circumstance. As the first author, Dr. Chen has authored dozens MW/RF publications and patents (includes US patent) about MW/RF design and reliability. His current research interests include but not limit to MW/RF circuit, high power MW/RF device, MW/RF nonlinear distortion effect in wireless communication with its OTA measurements.

Title:  Overview of PIM test calibrations with its improvement by tunable PIM standard

Abstract:
The traditional calibration method for passive intermodulation (PIM) measurement, also as IEC 62037 recommended, is realized using a tested low PIM load or several PIM fixed value standards to check if the PIM test loop (excluded DUT) has a low PIM status or equal PIM response. This method works in most cases. However, as the potential nonlinearities are widely spread in all kinds of microwave devices, the PIM calibration just based on the low PIM statue of whole test loop is not sufficient. For example, when the test PIM values are higher than the residual PIM level or the to-be-calibrated PIM level is not equal to the reference levels, the PIM test cannot be calibrated, much less the fake low PIM statue caused by the cancelling effect by multiple nonlinear sources. All these makes the traditional PIM test method has the potential to un-observably lose the test confidence or cause un-observable test error. In contrast, a tunable PIM source based calibration method arose, this method can provide a series of continual PIM references to verify all the test values in the testable ranges, the test accuracy can be ensured accordingly. Together with the PIM amplitude calibration, this work proposes a solution to realize the PIM phase tuning and calibration, which can ensure the test accuracy for the phase information of PIM sources. Under this technical background, this work introduces several kinds of techniques to generate tunable PIM amplitude. Targeted to PIM measurement, all the reported techniques would be able to provide weak PIM level that smaller than -112 dBm @ 2x43 dBm. Further, some improvements for several specific application scenes are introduced, these improvements cover increasing tunable dynamic range, bi-directional propagation, wideband PIM response, and PIM phase tuning.