Research On Millimeter-Wave Passive Components And Antennas

With the ever increasing demand for high-rate wireless communications and high-resolution detection systems, the advantages of millimeter-wave such as wide operating bandwith, narrow beamwidth, and ability of penertrating frog, smoke and dust are becoming more and more attractive. In recent years, millimeter-wave systems have been widely used in areas of such as communications, tracking systems, guidance of weapons and so on.This dissertation mainly focuses on the design and analysis of high-performance millimeter-wave passive components and antennas. The main contributions of this dissertation are listed as below:1. LTCC substrate integrated waveguide (SIW) cavity filters with sharp cutoff skirts are proposed and implemented to design a diplexer. An LTCC60GHz filter with one transmission zero is analyzed and optimized with konwledge-embedded space mapping (KSM) method as well as commercial full-wave softwares. Then, an LTCC60GHz filter with two transmission zeros is designed to realize sharp cutoff skirts at both sides of the passband.2. Novel and compact LTCC SIW cavity diplexers are proposed. A novel kind of LTCC40/50GHz diplexer without traditional T-junction is proposed. With furhter improvment, a more compact size and higher isolation is achieved when this kind of diplexer is applied to60GHz band.3. Millimeter-wave wideband antennas based on PCB and LTCC technologies are proposed. The self-complementary technology is used to design a wideband quasi-Yagi antenna on PCB. The impedance bandwidth of the proposed quasi-Yagi antenna has been improved from about30%in traditional designs to over70%. With the help of the LTCC technology, a wideband microstrip antenna which can cover all the four channels defined in the60GHz communication standard is proposed. This kind of antenna is also implemented to form a4×4planar array for a high gain and a1×4beam-steering array using a Butler matrix for efficient broad beamwidth coverage.4. LTCC and on-chip low-loss antennas for millimter-wave applications are proposed. A dielectric resonator antenna (DRA) and antenna array whose dielectric resonator and feeding network are both designed using LTCC process is proposed. The dielectric resonator does not sufer from the surface wave loss and the conducotr loss, as a result, the proposed LTCC DRA has realized a higher radiation gain than those normal and improved LTCC microstrip antennas. Since the gain of millimeter-wave on-chip antennas are relative low due to the semi-conductor substrate, an improved micro-electromechanical systems (MEMS) method is proposed. In this method, the silicon material is removed underneath the antennas to produce a cavity surrounded by metal and filled with polymer. This polymer filled cavity isolates the antenna and the lossy silicon substrate; meanwhile, it provides a better support to the membrane where the antennas are fabricated on than an conventional air cavity.135GHz micro-machined on-chip antenna and antenna array are fabricated using the proposed method and show good radiation performance in our measurement.