Three dimensional packaging and interconnecting techniques for microwave modules
Three dimensional (3D) packaging and interconnecting techniques can greatly reduce the weight and volume of conventional planar microwave modules. The objective of this study was to employ a novel 3D structure with simple manufacturing process to develop 3D microwave modules. Many advanced 3D packaging and interconnecting methods, such as LTCC microwave multichip modules, vertical interconnects, and 3D electromagnetic field analyzing and optimizing, were applied to increase the package density and improve the electric performance. Test method and test results of 3D microwave modules were introduced. These techniques are very useful to many types of modern active phased array radar systems and communication systems.
High density packaging of X-band active array modules
A new high-density package design has been used to reduce the cost, weight, and size of X-band active array radars. The package used multilayer aluminum nitride (AlN) substrates, flipped monolithic microwave integrated circuit (MMIC) chips, coplanar waveguide transmission lines, and solderless fuzz button interconnects. This paper discusses the design tradeoffs, the package construction and assembly, and test results.
Mechanics of deformable directed surfaces
Abstract The paper develops a simple, yet complete and consistent non-linear dynamic thermo-elastic shell theory based on the concepts of a two-dimensional directed continuum. The constitutive equations are postulated in a general form. Stress-strain relations are derived using the equation of energy balance and the two entropy production inequalities, which are rewritten in a special form. The linear theory is discussed in detail. The structure of the stress-strain relations is presented in the most general form and then specialized to concrete examples, in particular, to the classical shell theory, using their invariance properties with respective to certain symmetry groups. The elastic moduli are determined by demanding the coincidence of the frequency dispersion surfaces obtained using the two-dimensional theory with the lowest foils of the corresponding surfaces resulting from the three-dimensional theory of elasticity.