120-GHz and 240-GHz Broadband Bow-Tie Antennas in eWLB Package for High Resolution Radar Applications

In this paper, we present two broadband bowtie antennas working in D-Band (110GHz–170GHz) and J-Band (220 GHz–325 GHz) frequency range. Both antennas are designed in embedded wafer level ball grid array (eWLB) package from Infineon and are intended for high resolution radar applications. Achieving wideband performance in terms of return loss and antenna gain at millimeter and sub-millimeter-wave frequencies is a major challenge in an eWLB package because of the relative thickness and size of the package with respect to the operating frequency. This leads to unwanted surface currents and parasitic radiations from the sidewalls of the package. In order to alleviate this problem the antennas and the size of the package are co-designed. Measurements of the D-band and J-band antennas show a 3-dB gain bandwidth from 107 GHz–130 GHz and 227–252GHz while demonstrating a peak gain of around 6 dBi and 4 dBi, respectively. These antennas demonstrate that achieving wideband performance in an eWLB system-in-package is not only feasible but offers a highly attractive and robust solution for current and future radar applications.