Study on Impedance Matching of 2.4 GHz Dipole Antenna

Abstract

Understanding on matching impedance between feedline and load is important in many aplication. Theoritically, matching impedance can be calculated easily if charateristic impedances both load and line is known. Practically, when we do impedance matching at certain frequency we face a problem if the impedance of the feedline and antenna are unknown. by using vector network analyzer and anechoic chamber we tried to study and to approach the impedance match through measurement of return loss, VSWR, and antenna radiation pattern. The results of studies have shown that adjusting dipole antennas to lines can be done by optimizing antenna and lines length and subsequently optimizing the use of balun. In this reasearch we optimized 2.4 GHz dipole antenna and matched it to feedline by using bazooka and balun 1 : 1. To achieve good matching, the antenna length is 0.35 λ and the feedline length multiplies 0.5 λ. The length of the bazooka and balun for the best impedance adjustment are 0.25 λ and 0.2λ.