Audio frequency ground integrity modeling and measurement for a TDMA smartphone system

In this paper, we first propose a ground network model of an arbitrary shaped multi-layer printed circuit board (PCB)/chassis for accurate and efficient analysis of audio frequency ground noise coupled from a time division multiple access (TMDA) RF power amplifier (PA) to an audio circuit in a smartphone system. We designed test vehicles with varied extent in the ground noise coupling. We successfully verified the proposed model by comparing the ground noise coupling levels obtained from the model, 3-D electromagnetic (EM) simulation and measurement in time and frequency domain. We further discussed the performance of the proposed model by comparing the accuracy of its transfer ground impedance (ZG12) and analysis time with those of from the EM simulation. The proposed model showed high performance with the ZG12 agreed 91.7 % with the EM simulation, and the analysis time 95.5 % reduced compared to the simulation.