Research On LTCC Technology Of Microwave And Millimeter-wave Front-End

Recent research and investigations have proved the LTCC technology (Low Temperature Co-fired Ceramic) as one of the most promising solutions among MCM-C. Due to its good performance, it has become a hot research branch towards high-density integration, especially in the field of microwave and millimeter-wave design. The focus of this thesis is on some key skills and techniques when designing LTCC based microwave and millimeter-wave front-ends, namely divided in five parts: rectangular waveguide-microstrip transition in millimeter-wave frequency band, bandpass filters in microwave and millimeter-wave frequency band, microwave digital phase shifter, millimeter-wave broadband switch filter module, and front-end system.1. Rectangular waveguide-microstrip transition in millimeter-wave frequency band: Traditional constructions for transition in millimeter-wave are no longer suitable for LTCC technology, which is mainly for the limitation of LTCC fabrication process. Under this background, several novel transitions based on LTCC is proposed in this thesis, including the SIR slot waveguide-microstrip transition in Ka band, E-plane probe waveguide-microstrip transition in W band and the SIW-based waveguide-microstrip transition in W band. All the measured results of these transitions are good.2. Bandpass filters in microwave and millimeter-wave frequency band: A U-type SIR bandpass filter and a folded SIR bandpass filter are proposed. They have the merits of compactness, while maintaining a good filtering function. Some SIFW bandpass filters are proposed as well: H-plane septa SIFW bandpass filter, H-plane slot SIFW bandpass filter, H-plane septa and slot SIFW bandpass filter, and dual-H-plane septa SIFW bandpass filter. The measured results show good performance. What is more, a novel type transmission line, HMSIFW, is proposed in this thesis. To validate the transmission line structure, an H-plane spta and slot HMSIFW bandpass filter is proposed and measured. 3. Microwave digital phase shifter: A Ku band six-bit phase shifter with traditional single-layer PCB technology is designed. Then, a novel switched-line with loaded-line phase shifter is proposed, which could realize wide non-dispersive phase shifter. Using the novel filter structure, an X band four-bit phase shifter is designed. The measured results show good performance.4. Millimeter-wave broadband switch filter module: Using a novle three-line bandpass filter and a traditional E-plane waveguide bandpass filter, a four-way and two-way switch filter modules are designed. All the modules mentioned above get good measured results. With the experience of previous work, a five-way switch filter module is designed.5. Design of LTCC front-end systems: Front-end systems design includes an X band twice-frequency-conversion receive front-end and a Ka band transceiver front-end. Both of the two are realized by the high-density advantage of LTCC technology. Their measured results reach the design specifications.