60 GHz monolithic SiP transmitter integrating MMICs on LTCC multilayer circuits

Abstract

This dissertation presents two LTCC SiP transmitters, the smallest transmitter and a surface mounting type of a transmitter monolithically integrating both a BPF and an antenna, for 60 GHz wireless communication mobile terminal applications. Using a tow temperature co-fired ceramic (LTCC) based System-in-Package (SiP) technology, these transmitters integrate MMICs on LTCC multiplayer circuits. The size of the smallest LTCC SiP transmitter is 21 $\times$ 10 $\times$ 1 $mm^{3}$ and the monolithic LTCC SiP transmitter first integrating both a band pass filter (BPF) and an antenna is downsized to 36 $\times$ 12 $\times$ 0.9 1 $mm^{3}$. Implemented transmitters are demonstrated through measurements and 60 GHz wireless communication test. In particular, possible four key issues for the three dimensional (3D) integration of millimeter-wave (mm-wave) circuits are clarified in respect of LTCC technology, attenuation, resonance an isolation, and LTCC passive circuits. Several novel methods to solve these problems are proposed and demonstrated through electromagnetic (EM) simulations and measurements. Adopting these demonstrated methods, the smallest and the monolithic LTCC SiP transmitters are designed and implemented for 60 GHz wireless communication terminal applications. Firstly, for a LTCC technology for 3D system integration, a LTCC process library and design rules for vertical interconnections and planar interconnections are built using process control monitor (PCM) test patterns. In addition, in order to reduce a dielectric loss of transmission lines and a parasitic shunt capacitance, novel air cavity process is proposed and implemented. Secondly, novel transmission line structures and novel transitions are proposed and implemented using embedded air cavities and a stagger via structure for reduction of attenuation of the SiP. To reduce losses of transmission lines, innovative microstrip lines and stripline structures are invented. Measurements of the novel mi...