Miniaturized Quad-Band Filter Design Using Substrate Integrated Coaxial Cavity.

Area of Science:

• Electrical Engineering
• Electromagnetics
• Microwave Engineering

Background:

• Miniaturization is crucial for modern electronic devices.
• Traditional filters often occupy significant space.
• Substrate-Integrated Waveguide (SIW) cavities offer integration but can be bulky.

Purpose of the Study:

• To propose and demonstrate a miniaturized quad-band filter (QBF).
• To achieve significant size reduction compared to conventional designs.
• To explore the use of substrate-integrated coaxial cavities (SICCs) for multi-band filtering.

Main Methods:

• Design of a novel SICC structure with vertically stacked substrates.
• Segmentation of an embedded circular patch into four pieces.
• Utilizing blind vias to short the patch segments to the bottom wall.
• Fabrication and experimental measurement of a prototype QBF.

Main Results:

• The SICC structure demonstrated four independently controlled resonances.
• Achieved resonant frequencies were significantly lower than conventional SIW cavities.
• The designed filter exhibited substantial size reduction.
• Experimental measurements showed good agreement with simulation results.

Conclusions:

• The proposed SICC-based QBF effectively achieves miniaturization.
• This design offers a viable solution for compact multi-band filtering applications.
• The SICC structure provides a promising platform for future filter designs.