Circular polarization characteristics of one-wavelength L-shaped antenna

In this paper, we propose a circular polarized antenna, which is one-wavelength L-shaped structure with one feed point. The proposed antenna is composed of two elements, which have slightly different length, and the feed point is arranged on the corner point. The length of the two elements is adjusted and the circular polarization characteristics are calculated by using the moment method. As a result, we make clear the principle of the proposed antenna that the circular polarization can be obtained by adjusting design parameters so that the phase difference of excitation currents on the two elements is in agreement with the included angle between the two elements. Moreover, we make an experiment on a fabricated slot type model of the proposed antenna and demonstrated its favorable impedance matching characteristic. The L-shaped and simple feeding structure of the proposed antenna is suited to be built in the corner of front panel of small radio equipment for wireless LAN systems.