Highly Integrated LTCC and LCP Millimeter Wave Functions For 3D-SOP High Data Rate Wireless Systems

This paper presents the development of highly integrated millimeter waves function in multilayer LTCC and Liquid Crystal Polymer technology. Both ceramic and organic technologies are candidate of choice for the 3D integration, following the system-on-package concept, of compact, low cost, millimeter-wave high data rate wireless systems. Compact and easy-to-design passive functions such as directional filter and band pass filter have been demonstrated with excellent performances and high integration potential. Directional filter represents a fundamental device class enabling a compact hybrid passive mixer solution for millimeter wave direct modulator since they combine multiple filtering functions, reducing complexity while maintaining compactness. Easy implementation in standard LTCC technology has been demonstrated by using vertically coupling mechanism. Liquid Crystal Polymer (LCP) is a organic material that offers a unique combination of electrical, chemical and mechanical properties, enabling high frequency designs due to its ability to act as both the substrate and package for multilayer constructions. A band pass filter was designed to enable a low cost, very easy to design filtering solution to be integrated into a wireless millimeter-wave gigabit link system. The design exploits successfully the ripple of modified stepped impedance Tchebyscheff low pass filter combined with a rejection stub to create a wideband band-pass response center at 60 GHz. Insertion loss as low as 1.5 dB has been measured demonstrating the potential of LCP for millimeter-wave applications.