Suspended PCB Antenna Filter With Air-Gap Resonators for Miniaturization

The patent uses printed circuit board traces to create resonator structures that replicate the electromagnetic resonance characteristics of traditional metal cavity resonators. The PCB resonators are designed with specific geometric patterns (meander lines, loops, or open-stub structures) that copy the resonance behavior of metal cavities while being manufactured using standard PCB fabrication processes, thereby maintaining filtering performance while reducing structural complexity and manufacturing difficulty.

The patent replaces mechanical metal cavity structures with electromagnetic field-based PCB trace structures. Instead of using physical metal resonators that require precise mechanical fabrication and assembly, the invention uses conductive traces on PCBs that are formed through automated printing and etching processes, substituting a mechanical system with an electromagnetic field-based system that is easier to manufacture and integrate.

The patent transitions from three-dimensional metal cavity resonators to two-dimensional PCB trace resonators. By flattening the resonator structure onto a planar PCB substrate, the filter achieves miniaturization while maintaining its electromagnetic resonance function. This dimensional reduction allows the filter to occupy less volume and be more easily integrated into compact wireless communication devices.

The patent integrates multiple resonator structures within a compact PCB footprint by arranging resonator traces in nested or space-efficient patterns. Multiple resonators can be positioned close together on the same PCB layer or distributed across multiple layers, allowing the filter to achieve its required frequency response characteristics while occupying minimal space.

The patent replaces mechanical metal cavity fabrication and assembly processes with automated PCB manufacturing processes. PCB resonators are created using standard industry processes such as photoetching, lamination, and plating, which are highly automated and suitable for mass production. This substitution eliminates the need for complex mechanical assembly steps and enables high-volume manufacturing with consistent quality control.

The patent designs PCB resonator structures that can be manufactured using standard PCB fabrication processes, making the filter compatible with existing manufacturing infrastructure. The same PCB manufacturing line can produce different filter designs by changing the trace patterns and geometries, providing universality and flexibility for mass production of various filter types without requiring specialized equipment or processes.