SOI Antenna Switch Module Integrating Filter for RF Signal Isolation

The patent combines the antenna switch and filter functions into a single integrated module. The switch die includes both the switching elements and filter elements (capacitors and inductors) on the same substrate, merging multiple functions that traditionally required separate components. This integration directly reduces the overall module area while maintaining the capability to handle multiple RF signal paths.

The patent utilizes three-dimensional packaging techniques, including flip-chip mounting and vertical stacking of conductive layers within the switch die. By transitioning from a planar two-dimensional layout to a three-dimensional structure with multiple conductive layers stacked vertically, the design achieves higher functional density in a smaller footprint, reducing the module area while supporting multiple signal paths.

The patent integrates the filter function directly into the switch die, combining what were traditionally separate switch and filter components. This integration eliminates the need for separate filter components and their associated interconnects, reducing the number of interfaces and connections where signal loss occurs. The merged structure provides both switching and filtering in a single optimized path, reducing overall insertion loss.

The patent segments the RF signal paths into distinct, optimized routes within the switch die, with each path carefully designed to minimize losses. The filter elements are strategically positioned along each signal path to provide frequency-selective filtering that prevents unwanted signals from entering the switching network, thereby reducing interference-related losses and improving overall signal integrity.

The patent merges the filtering function into the switch die structure, creating integrated filter-switch assemblies. The filter elements (capacitors and inductors) are positioned in close proximity to the switching elements on the same die, creating a unified structure that provides both path selection and frequency-selective isolation. This integration enhances the ability to isolate different signal paths while maintaining access to multiple components.

The patent implements localized filtering at each signal path within the switch die, rather than using a single global filter. Each RF signal path has its own filter elements positioned adjacent to the switching elements for that path, providing path-specific frequency selection and isolation. This local quality approach ensures that each signal path maintains high isolation from others while still allowing multiple components to access the antenna through their respective optimized paths.