Muthanna Journal of Engineering and Technology
Volume (14), Issue (4), Year (2026), Pages (26-34)
DOI:10.52113/3/eng/mjet/2026-14-04-/26-34
Research Article By:
Yasser Abdul Karim Alramahi and Ayad Muslim Hamzah
Corresponding author E-mail: yasser.alramahi.ms7@student.atu.edu.iq
ABSTRACT
This work presents the design, simulation, fabrication, and experimental validation of scalable substrate integrated waveguide (SIW) slot antenna arrays operating at 26 GHz for 5G millimeter-wave applications. The proposed structure is developed progressively from a single SIW radiating element to 2×1 and 4×1 linear arrays, which enables a systematic evaluation of impedance matching, array scalability, corporate-feed performance, and radiation behavior. All configurations are implemented on a Rogers RT/duroid substrate with a relative permittivity of 2.2 and a thickness of 0.508 mm, and the numerical analysis is carried out using CST Microwave Studio. The fabricated prototypes are experimentally validated using a vector network analyzer. The measured return losses are approximately -20 dB, -25 dB, and -30 dB for the single element, 2×1 array, and 4×1 array, respectively, confirming stable resonance close to 26 GHz. The measured -10 dB impedance bandwidths are 1.4 GHz, 1.5 GHz, and 2.0 GHz, respectively; therefore, the 4×1 array satisfies the 2 GHz bandwidth criterion considered for the target 5G millimeter-wave operation. The simulated gains are 7.2, 8.5, and 10.2 dBi, while the measured gains are 7, 8.1, and 10 dBi for the same three configurations. These results show that the proposed SIW slot-array design provides compact geometry, stable resonance, improved gain with array scaling, and practical measured performance for 26 GHz 5G applications.
Keywords:
SIW antenna, Slot antenna, 26 GHz, 5G millimeter-wave, 4×1 antenna array, corporate feed network