An innovative structure for thin-film band-pass filters was proposed and analyzed. This structure was employed in the design, fabrication, and development of 3D IPD diplexers on glass substrates with double-side metallization electrically connected by through-vias. Through modeling, design, fabrication and characterization of the WLAN 3D IPD glass diplexers, the proposed filter structure was shown to enable miniaturized and high-performance RF passives. Further, component-level shield structures were developed to provide electromagnetic interference isolation between thin-film passives that are placed less than 100 µm apart. Glass substrates were designed, fabricated and characterized to demonstrate the shield effectiveness of metallized trench and via-array-based shields. The integration of such shields in miniaturized WLAN RF modules enables up to 60dB EM isolation in the frequency range of 1- 20GHz. Advanced RF module technologies based on 3D IPAC concept were designed and demonstrated with ultra-thin low-loss organic and glass substrates, integrating the proposed WLAN actives with miniaturized diplexer and EM shields. Double-side integration of such high-performance components on ultra-thin glass substrates enables up to 8x volume miniaturization including more than 3x reduction in area. Thus, the advanced components demonstrated in this research, vis-a-vis miniaturized diplexers and component-level EMI shields; integrated with actives in ultra-thin glass substrates using the 3D IPAC concept, can enable highly-miniaturized smart systems with multiband wireless communication capabilities.