The master’s thesis defense for Ms. Nour Kareem Mohsen took place on Monday, August 4, 2025, at 09:30 AM. The thesis, titled:

“Design of Compact Sub‑6 GHz Filtering Patch Antenna with Enhanced Bandwidth and Gain for 5G Applications”

was supervised by

Professor Dr. Durgham Kamal Naji.

The work is divided into two major parts:

Part I focuses on a reconfigurable filtenna for UWB applications.

The design integrates edge chamfering and a low-pass filter (LPF) within the feedline to enhance selectivity. It achieves a remarkable 100% fractional impedance bandwidth (2.7–8.1 GHz) in UWB mode. The antenna can also be reconfigured to operate as a narrowband antenna centered at 3.5 GHz (WiMAX), delivering a gain of 1.7 dBi.

The filtering mechanism is realized using a stepped impedance transmission line and a fractal H-shaped structure embedded within the microstrip feedline. Fabricated on an FR4 substrate, the prototype demonstrates a −10 dB impedance bandwidth of 36% (2.5–3.6 GHz). Both simulation and experimental results, obtained via CST Microwave Studio (MWS), confirm its effectiveness for UWB applications.

Part II presents a compact Filtering Patch Antenna (FPA) aimed at 5G sub-6 GHz systems.

This design features a radiating patch with an inscribed circular slot, a quarter-wavelength matching strip integrated into the feedline, and a partial ground plane with a T-shaped branch strip that introduces radiation nulls at the passband edges. These structural features significantly enhance impedance bandwidth, gain, and radiation efficiency. The measured −10 dB fractional impedance bandwidth reaches 47.36% (2.9–4.7 GHz), with improved selectivity and stopband suppression levels of over 22 dB and 23.7 dB at the lower and upper band edges, respectively. The antenna exhibits a compact footprint of 29×35×0.8 mm³, omnidirectional radiation patterns, and a gain of 3 dBi. Simulations were carried out using CST Microwave Studio (MWS) and HFSS.

Both designs, despite sharing similar physical dimensions, offer significant advancements in antenna technology by achieving compact, single-layer, low-profile structures with integrated filtering, high performance, and efficiency. These results confirm the viability of combining filtering mechanisms with radiating structures to meet the rigorous requirements of next-generation wireless communication systems.