DESIGN AND IMPLEMENTATION OF A Q-BAND MILLIMETER WAVE PLANAR LENS ANTENNA

摘要

A Q-band planar lens with four substrates separated by air gaps is investigated. The efficiency, gain, and back lobe level are improved by shifting the sizes of the cells with dual square slot loops on different substrates. Besides, the compensated phase of each compound cell which consists of the corresponding square slot loop cells distributed in the four substrates is calculated using an equivalent phase other than the phase at the center of the cell. Three hundred and sixty degree compensated phase can be achieved by changing the sizes of the outer and inner slot loops of the cell. The side length of the lens is 144 mm or 20 wavelengths. The air gap between the substrates is 2 mm. The number of cells is 2025 or 45 by 45. The lens is fed by a linear polarized horn antenna with a gain of 15 dBi approximately. The measured peak gain is more than 33 dBi at 44 GHz, and the half power beam width of E-plane and H-plane are about 2.9 degrees. The lens could cover from 43 to 47 GHz or more than 9% bandwidth. The side lobe level is under-20 dB, and the measured front-back-ratio is better than 20 dB. The measured data are in agreement with the simulated results. (C) 2015 Wiley Periodicals, Inc.