RF Designs and Simulations

BGA Package Design and Simulation A BGA package is very popular package style for high speed digital applications due to high density, low thermal resistance, and low inductance leads. In a BGA package, the electrical connections are made of solder balls stuck to the bottom of the package. However as the operating frequency and data rate go up, it is critically important for IC designers to understand the package’s electrical performance because of the parasitics that can come from the package. A package is the second most expensive part next to the silicon and can add 6 to 8 weeks to the cycle time. Given the very tight opportunity window for the majority of digital products, a failure to produce a successful package design can significantly reduce the profit margin or even kill the entire project. Designers are challenged to get the desired package performance right the first time. It requires fast and accurate analysis of BGA packages with EM simulators. A 45 mm pack...

Multi-layer Microstrip Antenna Generally impedance bandwidth of patch antennas varies from 2-3% for single layer direct coupling or probe coupling  and can be further enhanced by coupling the power from the strip line through an aperture (slot) in the ground plane and/or printing patch effectively on the foam material whose dielectric constant is nearly equal to that of air [. In such case the feed network is isolated from the radiating element by a ground plane, which prevents spurious radiation. The resonant or non-resonant slot couples energy from the stripline to the patch. If slot is resonant, it provides another resonance in addition to the patch resonance, resulting in an antenna with 10-15% impedance bandwidth. However, the resonant slot has strong backlobe, which substantially reduces the gain of the antenna. Non-resonant slot has better front to back ratio, which results in improvement in efficiency with narrow bandwidth. Hence multilayer microstrip antennas are di...