Design of Reconfigurable Optical on Folded Dipole Antenna Based Resonator and Vector Network Analyzer (VNA) Aslam Chitami Priawan Siregar a) , Yono Hadi Pramono b) , and Gatut Yudoyono c) Department of Physics, Institut Teknologi Sepuluh Nopember, Surabaya, Indonesia. a) aslamsiregar01@gmail.com b) yonohadipramono@gmail.com c) gyudoyono@physics.its.ac.id Abstract. A folded dipole antenna with a microstrip structure is designed in the super high frequency (SHF) range with a size of 15 × 3.1 × 0.03 mm. Then, a photodiode was installed and irradiated with infrared 808 nm, 200 mW on it. Based on the measurement results using a vector network analyzer (VNA), there was a change in frequency from 13.86 to 14.85 GHz before and after infrared irradiation. Next, a resonator is installed on it. So, the frequency changes from 16.29 to 4.86 GHz before and after being irradiated by infrared. The very wide frequency shift in the antenna can be applied to mobile phones with 5G technology. Keywords. Antenna, Folded Dipole, Infrared, Photodiode, Resonator. 1. INTRODUCTION With increasing technological advances, an antenna is needed that can absorb and emit electromagnetic wave radiation on a big scale. In this study, a folded dipole antenna with a microstrip structure is proposed. It was chosen because it has a simple shape, low price, easy fabrication, and is lightweight (1). To be applied to mobile phones or other wireless communications, it is designed with dimensions in millimeter scale. So, it can operate at a super high frequency (SHF) and produce high electromagnetic waves (2). Next, to improve the work of the antenna when in an area low signal, it is necessary to make a reconfigurable antenna by installing a photodiode. Then, the photodiode was irradiated with infrared 808 nm, 200 mW. Furthermore, the folded dipole antenna is added by installing a resonator in order for the work can be improved further (3)(4). The resonator is mounted on the folded dipole antenna feedline. With the resonator, it is expected that a wider frequency change will occur when irradiated with infrared as an optical reconfigurable. 2. METHODS In this study, a folded dipole antenna made of copper plates with a size of 15 × 3.1 × 0.03 mm was printed on FR- 4 (ε r = 4.4) with a thickness of 1.6 mm using a laser jet printer (5)(6). Its shape can be shown in Figure 1. Furthermore, the folded dipole antenna is attached to a connector. So that it can be measured using a vector network analyzer (VNA) (7). The type of VNA used in this study is Saluki Technology S5105D which can work in the 30 kHz - 18 GHz frequency area. Then, it is installed photodiode as shown in Figure 2. The photodiode is illuminated by infrared so that it can work as an optical reconfigurable (8)(9).