Advanced 3D LTCC passive components using cavity structures for 60 GHz gigabit wireless systems

In this paper, a new class of compact cavity-based three dimensional (3D) filters and enhanced-performance antennas is proposed for 60 GHz miniaturized front-ends for multilayer low-temperature co-fired ceramic (LTCC) V-band modules. The low-loss cavity resonator consisting of via fences as sidewalls has been designed to be used as a filter. The probe excitation is employed for the feeding structure and is demonstrated as an attractive option for wideband applications due to its relatively wide bandwidth performance (1.8%) compared to the slot excitation with a lambda_g/4 [1]. Its low loss performance is verified through an insertion loss lower than 0.95 dB over the 3-dB pass band. Plus, an aperture-coupled patch antenna integrated with a soft surface and an underlying stacked cavity below the antenna substrate has been demonstrated on a novel LTCC composite multilayer technology with variable layer dielectric constant as a potential enhanced-performance antenna topology with a higher gain (~7.6 dBi) and a significantly lower backside radiation (at least 5.1 dB) as compared to the use of soft surface only. The proposed compact antenna topology is easily extendable to array configuration for point-to-point applications in short-range indoor wireless personal area networks (WPAN).