Compact spaced-dual-band filtering via ridge-gap waveguide for enhanced satellite communications

Neetirajsinh Chhasatia, Jitendra Chaudhari, Hiren Mewada, Amitkumar V. Patel, Keyur Mahant, Y.P. Kosta

This paper presents a novel spaced-dual-band filter based on ridge-gap waveguide (RGW) technology, designed with a cascaded structure of two ridge-gap waveguide units. The filter offers two distinct passbands, separated by a frequency gap of 4 GHz. In comparison to spaced-dual-band filter utilizing substrate integrated waveguide (SIW) technology, the proposed RGW filter demonstrates superior performance characteristics. It achieves a lower insertion loss, narrow bandwidth, and improved return loss, making it highly suitable for high-frequency applications. Parametric analysis is conducted on the unit cell, demonstrating the precise control of stop band by manipulating the airgap between pins and the top metal plate, pin height, and base thickness. The proposed filter's fabrication process benefits from standard precision molding techniques, and its compact size of 3.8 λ 0 × 2.1 λ 0 further enhances its practicality. Notably, the filter exhibits an insertion loss of better than 0.16 dB and better return loss across two passbands, highlighting its excellent performance. This research introduces a promising advancement in spaced-dual-band filters, with potential applications in communication systems, radar systems, and medical imaging. The adoption of ridge-gap waveguide technology represents a significant step forward in high-frequency filter design, paving the way for further exploration and development in this domain. • Novel dual-band filter using ridge-gap waveguide with two distinct passbands. • Achieves superior low insertion loss and improved return loss in high-frequency applications. • Compact design ( 3.8 λ g × 2.1 λ g ) with precise control over dual-band response. • Promising applications in satellite communications, radar, and medical imaging. • Utilizes standard microfabrication techniques for practical and efficient implementation.