Bulletin of Electrical Engineering and Informatics
Vol 15, No 4: August 2026

Design and realization of X-band wideband directional coupler using elliptical multilayer substrate architecture

Shilpa Ankit Rana (Gujarat Technological University)
Ashish Kalubhai Sarvaiya (Government Engineering College)



Article Info

Publish Date
01 Aug 2026

Abstract

This paper presents the design analysis and realization of a wideband directional coupler tailored for X-band microwave applications. Directional couplers are critical components in modern microwave systems, where wide bandwidth and compact size are essential. The proposed design employs a multilayer configuration using TLY-5 substrate (epsilon r=2.20 and tangent delta=0.003), with a thickness of 0.508 mm and 17 µm copper cladding. The coupler is designed and simulated using Ansys high frequency structure simulator (HFSS) and subsequently fabricated for performance validation. It achieves a coupling factor of 3.5±0.6 dB across the 7–14 GHz range, with a transmission loss of 2.9±0.5 dB. Both return loss and isolation consistently exceed 20 dB throughout the operational band. The design exhibits a fractional bandwidth (FBW) of 66.67%, confirming its broadband capability. With a compact footprint of 2.475 lambda g ×1.485 lambda g, the coupler offers reasonable impedance matching and broadband performance, making it well-suited for integration in microwave circuits, particularly in variable attenuators and wideband communication systems.

Copyrights © 2026






Journal Info

Abbrev

EEI

Publisher

Subject

Electrical & Electronics Engineering

Description

Bulletin of Electrical Engineering and Informatics (Buletin Teknik Elektro dan Informatika) ISSN: 2089-3191, e-ISSN: 2302-9285 is open to submission from scholars and experts in the wide areas of electrical, electronics, instrumentation, control, telecommunication and computer engineering from the ...