tailieunhanh - Three-Dimensional Integration and Modeling Part 10

Tham khảo tài liệu 'three-dimensional integration and modeling part 10', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | THREE-DIMENSIONAL ANTENNA ARCHITECTURES 81 Also a slight polarization mismatch or and some objects near the antenna such as the connector or and the connection cable may considerably contribute to the high cross-polarization. In addition the maximum gain measured for the patch with the soft surface is near 9 dBi about 3 dB higher than the maximum gain and 7 dB higher than the gain at broadside for the antenna without the soft surface. HIGH-GAIN PATCH ANTENNA USING A COMBINATION OF A SOFT-SURFACE STRUCTURE AND A STACKED CAVITY The advanced technique of the artificial soft surface consisting of a single square ring of metal strip shorted to the ground demonstrated the advantages of compact size and excellent improvement in the radiation pattern of patch antennas in section . In this section we further improve this technique by adding a cavity-based feeding structure on the bottom LTCC layers substrate 4 and 5 in Fig. c of an integrated module to increase the gain even more and to reduce future backside radiation. The maximum gain for the patch antenna with the soft surface and the stacked cavity is approximately dBi that is dB higher than dBi for the soft-enhanced antenna without the backing cavity. Antenna Structure Using a Soft-Surface and Stacked Cavity The 3D overview top view and cross-sectional view of the topology chosen for the micostrip antenna using a soft-surface and a vertically stacked cavity are shown in Fig. a b and c respectively. The antenna is implemented into five LTCC substrate layers layer thickness 117 pm and six metal layers layer thickness 9 pm . The utilized LTCC is a novel composite material of high dielectric constant er in the middle layer substrate 3 in Fig. c and slightly lower dielectric constant er in the rest of the layers substrate 1-2 and 4-5 in Fig. c . A 50 G stripline is utilized to excite the microstrip patch antenna metal 1 through the coupling aperture etched on the top metal .