Nur Iffah Zulaikha Binti Azman creator author. text my 2024 2024 monographic eng xv, 126 pages : illustrations (some color) ; 30 cm. + 1 CD-ROM specialized Nur Iffah Zulaikha Binti Azman Faculty of Industrial Management Thesis (Master of Science ) -- Universiti Malaysia Pahang – 2024 This study explores the use of reduced graphene oxide (rGO) as a by-product in fabricating a bandpass filter (BPF) and patch antenna circuit. rGO is a versatile material with high surface area, excellent electrical conductivity, and mechanical strength, making it ideal for energy storage devices, sensors, and catalysis. The Microstrip BPF and patch antenna circuit are developed for their planar profile and ease of manufacture. However, there was issues like narrow bandwidth, low efficiency, low radio frequency power, and limited affordable material selections exist in electronic device fabrication. This work aims to synthesize a rGO paste using GO from exfoliation graphite (G), characterize its structural, thermal and morphological properties. Next, design and fabricate a rGO-based microstrip BPF and microstrip antenna for wide bandwidth, and high efficiency. The synthesis of rGO powder involved preparing GO from G powder using the improved Hummers method (IHM). GO was chemically reduced to rGO using ascorbic acid. The synthesized rGO powder was used in the fabrication of BPF and patch antenna circuit. rGO paste was formed by combining rGO powder with an organic carrier comprised of linseed oil, m-xylene, and α-terpineol. To create the rGO-based circuit, the rGO paste was screen-printed onto RT duroid 5880 substrates. The developed circuits were evaluated for paste-to-substrate adhesion. Then, the fabricated circuit was evaluated using a vector network analyzer (VNA) and compared with a simulation to acquire scattering parameter results including return loss (RL), insertion loss (IL), and bandwidth (BW). G, GO and rGO structural properties shows a dominant peak at 2θ; 26.24° (002), 9.42o (001) and 26.70° (002), respectively. Besides, there also several peaks at -OH and OH bending for all three materials. While. thermal properties obtained a weight loss for G, GO and rGO approximately; 13%, 82%, and 3%, respectively. For morphology properties of G appears as unevenly sized flakes, GO has the similar flake-like shape and rGO display a loose structure. The rGO based bandpass filter (rGO-BPF) circuit demonstrated excellent performance with RL, IL and BW values of -27.481 dB, -0.093 dB, and 1.042 GHz respectively. While, conventional simulation circuit obtained -26.750 dB, -0.770 dB, and 1.006 GHz, respectively. The fabricated of rGO based patch antenna (rGO-PA); the RL and BW for rGO antenna (RL: -17.6314 dB and BW: 0.2974 GHz) and conventional simulation circuit (RL: -18.0497 dB and BW: 0.1560 GHz) was obtained. From the result obtained, this work has wider bandwidth which make rGObased circuit has high efficiency and better performance. The calculation for rGO-based circuit result was successfully achieved since the rGO-based circuit outperformed the conventional circuit. Faculty of Industrial Management Dissertations Universities and colleges Dissertations Theses Dissertations THE0009901 (Local) UMPSA 240729 20251125110909.0 eng