Papers by Author: Li Qiang Zheng

Abstract: Return loss of wireless sensor network (WSN) node indicates the impedance matching between signal ports of the RF chip and the antenna, and thus shows the transmission efficiency in the signal path. All circuit components, including capacitors, inductors, PCB tracks, packaging parasitic and RF ports were modeled as equivalent passives, to achieve accurate simulation result of return loss of the WSN node. An optimization methodology of return loss was proposed based on the parameter sweep of the equivalent passive network simulation. With the help of the methodology, some critical components’ values were changed to obtain optimized RF performance for the wireless node. Measurements matched the analysis and simulation well and showed great improvement.

Abstract: In this paper, the effect of the substrate on wireless sensor network (WSN) node’s RF performance is studied experimentally by using different substrate materials with different thickness. A six-layer FR4 substrate PCB WSN node is fabricated and compared with the original two-layer FR4 PCB node to show the impact of substrate material thickness. Also different substrate dielectric constants’ impacts are studied by the same method. All these demonstrators are modeling by RF circuit analysis method and simulated in the Ansoft Designer software. Simulation results match the experimental measurement. An optimization method based on simulation for WSN node design with different substrate is presented. This analysis, modeling, simulation and optimization procedure can be carried out on some novel substrate materials such as LTCC and LCP.