This paper demonstrates, for the first time, 3D integrated passive device (IPD) diplexers on ultra-Thin glass substrates for wireless local area network (WLAN) application in mobile devices. The designed LC-based diplexer was composed of a low-band filter and a high-band filter, built on ultra-Thin glass substrates. The two filters were designed on each side of the glass substrate and interconnected by through-package-vias (TPVs) to form a 3D IPD. Ultra-Thin and low-loss dryfilm dielectrics were utilized for improved electrical performance as well as to achieve high-density of passives integration. The demonstrated 3D IPD diplexer is 3-4X thinner than current LTCC devices, with lateral dimensions of 1.1mm x 1.3mm in a thickness of 200μm resulting in a low insertion loss of less than 1dB for pass bands and more than 24dB stop-band rejection.
