A Design of Wideband Microstrip-to-Microstrip Vertical Transition for RF Circuits

Abstract

With the miniaturization of RF circuits, the transmission of signals in different layers becomes important. How to realize the vertical transition structure with wide transmission band and low loss has become the focus of research. In this paper, we proposed a broadband vertical transition structure design based on cavity coupling. This model achieves broadband coupling between the upper and lower microstrips by adding parabolic patches, which improves the model transmission bandwidth. The simulation results show that the optimized model has ultra-wideband transmission characteristic, the 1dB bandwidth is 3.32 GHz-10.42 GHz and the fractional bandwidth is more than 103%. What’ more, the thick ground layer of the model improves the heat dissipation performance. Therefore, this structure is very suitable for high-speed and high-density RF circuits.