The Realization Study on the Reconfigurable Functions of Radial Line Slot Array Antennas

This paper thoroughly studies the realization of the reconfigurable function of RLSA antennas in terms of beamsteering at the frequency of 5.8 GHz. In the first step, the study on the characteristic of small RLSA antennas concludes that maximum beamsquint that can be achieved is around 70[degrees]. In the second step, in order to minimize the size of reconfigurable RLSA antennas, a new technique of cutting a small RLSA into sectors is introduced. The analysis on the quarter cut RLSA and the semi cut RLSA shows that their performances do not deviate too much from the full circle RLSA performance. In the third step, study on the most suitable method of realizing the reconfigurable function of RLSA antennas chooses the method of implementing antenna array as the most suitable method. Based on this method, a structure of reconfigurable RLSA antennas is proposed. In the last step, utilizing the proposed structure and four quarter cut RLSA elements, a novel reconfigurable RLSA antenna in terms of beamsteering is simulated and fabricated. To avoid significant coupling effect between the antenna elements, all elements are separated by 20 mm. The antenna has a directivity of 9.2 dB, an efficiency of 97.95%, a bandwidth about 1.5 GHz, the mainlobe direction (in elevation direction) of 45 [degrees], the beamwidth of 32.5 [degrees], and the sidelobe level -6.3 dB. The beam of the reconfigurable antenna can be steered into four different azimuth directions, which are 0 [degrees], 90 [degrees], 180 [degrees], and 270 [degrees]. Furthermore, a similar radiation pattern and reflection coefficient between the measurement and simulation verifies the validity of the study.