Dual-Band Filter and Diplexer Design Using Extremely Miniaturized Substrate-Integrated Coaxial Cavity

Area of Science:

• Electrical Engineering
• Electromagnetics
• Microwave Engineering

Background:

• 5G communication systems require efficient front-end and signal-switching components.
• Conventional substrate-integrated waveguide (SIW) cavities occupy significant space.
• Miniaturization is crucial for integrating advanced functionalities into compact devices.

Purpose of the Study:

• To design and validate a highly miniaturized dual-band filter (DBF) and a diplexer for 5G applications.
• To introduce a novel substrate-integrated coaxial cavity (SICC) resonator.
• To achieve superior circuit area efficiency compared to existing SIW-based designs.

Main Methods:

• Development of a miniaturized substrate-integrated coaxial cavity (SICC) resonator.
• Implementation of a dual-band filter using two SICC resonators.
• Implementation of a diplexer using three SICC resonators.
• Design incorporates transmission zeros for enhanced selectivity and achieves high isolation (>20 dB).

Main Results:

• The proposed SICC structure occupies only 2.1% of the area of a conventional SIW cavity at the same frequency.
• Fabricated dual-band filter and diplexer samples show excellent agreement between simulated and measured data.
• The designs achieve high performance metrics including selectivity and isolation.

Conclusions:

• The developed SICC technology offers a pathway to highly miniaturized RF components for 5G systems.
• This work presents the most circuit area-efficient dual-band SIW cavity filters and diplexers to date.
• The proposed SICC-based filters and diplexers are suitable for integration into compact 5G devices.