Design of a New Millimeter-Wave 3D Stacked RF Front-End System Level Package

In the context of the gradual popularization of 5G mobile communication, the number of RF devices has increased significantly, and the complexity of RF systems has increased day by day. The RF system integration package is gradually developing in the direction of system level package, which puts forward the demand of miniaturization, multi-function and easy integration. In this paper, an RF system level package antenna module with a size of $26\text{mm}\times 26$ mm $\times$ 0.974mm and a center frequency of 97Ghz is designed. It integrates four RF front-end chip and a transceiver chip in the size of the antenna. It integrates a three-layer patch microstrip antenna with a total of 256 array elements and 64 channels in the package, and uses the H-shaped slot to achieve feed, so as to achieve more complex system integration. Packaging PCB boards using HDI materials has the advantage of facilitating a large number of integrations. After considering the requirements of electromagnetic isolation and effective interconnection, the detailed structural design is given in this paper. The electromagnetic characteristics of the RF system-level package module are simulated and evaluated. The simulation results show that when $\vert \text{SII}\vert < -10\text{dB}$ , the bandwidth of $2 \times 2$ array antenna is 5GHz, and the gain is 11.46dBi at 97GHz. The RF signal transmission path loss (S21) is controlled below 1.5dBi, and one RF SiP module channel gain is 9.8dBi.