Ultra-compact quad-band half-mode SIW bandpass filter for Sub-6 GHz 5G applications

Area of Science:

• Electrical Engineering
• Electromagnetics
• Microwave Engineering

Background:

• Sub-6 GHz frequencies are crucial for 5G wireless communication systems.
• Miniaturization and multi-band capabilities are key challenges in filter design for modern wireless devices.
• Existing filters often struggle to balance size, performance, and multi-band operation.

Purpose of the Study:

• To design and validate an ultra-compact, low-loss, multi-band bandpass filter (BPF) for sub-6 GHz 5G applications.
• To achieve a significantly reduced footprint while maintaining efficient wave propagation and supporting multiple passbands.
• To demonstrate the reconfigurability of the filter design for adaptable frequency band usage.

Main Methods:

• The filter is based on a half-mode substrate-integrated waveguide (HMSIW) structure.
• Metamaterial-inspired unit cells, including circular and serrated complementary split-ring resonators (CSRRs), are integrated.
• The design was simulated, fabricated, and experimentally characterized to validate performance.

Main Results:

• The proposed filter achieves an ultra-compact size (14.1 × 14.1 mm), occupying less than 0.004λg².
• Four distinct passbands are realized at 0.97 GHz, 2.58 GHz, 4.5 GHz, and 5.6 GHz with low insertion losses and high return losses.
• Measured results closely match simulation data, confirming the filter's efficiency and robustness.

Conclusions:

• The developed HMSIW-based BPF with metamaterial resonators offers a highly compact and efficient solution for sub-6 GHz 5G applications.
• The filter's multi-band and reconfigurable characteristics make it suitable for integration into various wireless communication systems.
• The design represents a significant advancement in miniaturized multi-band filter technology for next-generation wireless networks.