Analysis and design of post-wall waveguides for application in SIW

In the last decades, the use of electronic components operating at microwave frequencies has grown tremendously. Commonly known applications are related to satellite-based TV transmission, navigation based on GPS, mobile telephony, radar, and wireless local area networks. Also in the areas of defense and security, microwave technology has acquired a prominent position. The enabling technologies at the basis of this growth appear to be a wide variety of microwave components: antennas, feed networks, MMICs, amplifiers, mixers, filters, etc. Moreover, the level of integration of these technologies has evolved significantly. As component size continues to diminish, the need for innovation in the area of transmission-line structure conceptualization, design, and realization is apparent, in particular because intrinsic physical limitations such as proximity e_ects and loss become more and more manifest. Beside these constraints, cost and integration aspects led in recent years to the introduction of new concepts, materials, and production techniques. In Section 1.1 we describe the impact of these aspects and constraints on the antennas and front-ends of wireless systems. Subsequently, we consider these aspects in relation to the classical feed structures of wireless systems, i.e., planar transmission lines and waveguides, in Section 1.2. The discussion in these two sections reveals that new solutions for the transmission-line structure itself are needed. A promising alternative for the classical structures is the post-wall waveguide. We give a brief overview of its short history in Section 1.3. Based on this historical review and the corresponding literature reviews, we formulate in Section 1.4 the aims of this thesis related to the characteristics, analysis, design, and manufacturing of post-wall waveguides. Finally we summarize the contents of the thesis in Section 1.6.