Summary
International Symposium on Antennas and Propagation
2012
Session Number:2A3
Session:
Number:2A3-4
Gap Waveguide Components for Millimetre-Wave Systems: Couplers, Filters, Antennas, MMIC Packaging.
Esperanza Alfonso,
pp.-
Publication Date:2012/10/29
Online ISSN:2188-5079
Summary:
Gap waveguides are an alternative guiding technology especially attractive for frequencies over 30 GHz up to THz. At those frequencies, the current technologies show some deficiencies regarding to the performance, integration ability, or product cost. Planar technologies, such as microstrip and coplanar, are often chosen due to their good integration ability and manufacture simplicity, but they suffer from higher losses with increasing frequency as well as from the presence of cavity resonances when encapsulated. Hence, hollow waveguides are usually resorted for low-loss applications, in spite of their difficulty for integration with active components and a high manufacturing cost. The need of new transmission line technologies for mm- and sub mm-wave systems is leading to the apparition of alternative technologies. Substrate Integrated Waveguide (SIW) technology has been widely used for high-frequency applications, but it exhibits significant losses at increasing frequencies due to wave propagation in substrate. Gap waveguides, on the contrary, support waves in the air gap between two metal plates. One of the plates is provided with a texture, in the form of a bed of nails, to create a high impedance condition at the surface, which in turn forces a cut-off for the parallel-plate modes. On the same plate, there are metal ridges in between the nails providing a path to the waves so that fields are confined to the air gap between the ridges and the metal plate on top. This paper presents the progress made so far on the design of passive components and MMIC packaging demonstrated for RF front ends for microwave links at 38 GHz using gap waveguide technology. Initial designs are made at the microwave band for validation and measurement purposes, and for comparison with existing technology. But it is for millimeter- and sub millimeter-wave applications where gap waveguides represent a promising solution.