Design and Simulation of mm-Wave Diplexer on Substrate and Fan-Out Structure

Inter-digital and hairpin mmWave diplexer design and simulation based on two types technology: fan-out structure and build-up substrate for n257/n258 and n260 bands in 5G new radio (NR) are demonstrated in this paper. Fan-out structure has advantage of thin profile and smaller process variation. However, high loss dielectric material is a big concern that will increase the loss, especially in mm-wave band. On the other hand, conventional packaging substrate is believed to have smaller insertion loss due to various low loss material options, but the disadvantage is large process tolerance that probably results in significant RF performance variation. The objective of this paper is to study the pros and cons of conventional packaging substrate and advanced fan-out substrate from electrical point of view.