Gain Increase Modification Collinear Dipole Antennas for Secondary Surveillance Radar

Abstract

—In this research, an antenna design was developed using the wire-to-micros trip adaptation technique. The aim of developing the antenna is by modifying the change in position and shape of the antenna to get a large gain with a minimum value of 25 dB. This development is crucial for the use of Secondary Surveillance Radar (SSR). The design of the antenna used in this study is to improve the performance of modifying conventional dipole antennas to become collinear arrays. Collinear array antennas involve modifying dipole arms to form an array, incorporating a coupling effect on both the positive and negative arms, and strategically rotating the vertical placement by 180 degrees to maximize the resulting gain. The study involved three types of antenna arrays, each consisting of eight antennas: Mode A, unidirectional with opposite poles; Mode A, not unidirectional with opposite poles; and Mode B, unidirectional with opposite poles. Early research made comparisons of polar differences with polar similarities. For the results of a single polar difference antenna Mode A and B, where Mode A produces S11-26.884 dB with Gains 3.825 dB, Mode B produces S11-20.408 dB with Gains 2.364 dB, for research on array antennas, it was carried out in stages, with as many as 8 array antennas, without reflectors and with reflectors. In the final configuration, an antenna with an array of 112 antennas using reflectors to produce S11 for a frequency of 1.03 GHz of-15.53061 dB with Gain 26.52 dB and an Azimuth beam width of 0.9ᵒ and for the frequency 1.09as big-20.73117 dB with Gain 25.6 dB and an Azimuth beam width of 0.8ᵒ. These results indicate the successful achievement of improved antenna performance, including a reduction in reflection coefficient and an increase in gain. These findings contribute to the advancement of antenna design for SSR applications, showcasing the potential for substantial gains in signal strength and directionality.