Research On Millimeter Wave Antenna Unit And Array Based On Microstrip Structure

With the development of modern communications,there has been an increasing interest in antennas at millimeter-wave frequencies.This paper will focus on the the problem of realizing high-gain wide-band antennas with simple structures,and use the microstrip grid array antenna as the basic antenna.The main content includes the following two parts:1.Research on the high-gain rectangular-loop antennaBy designing a traditional closed-loop grid array antenna,a high-gain five-grid array antenna is achieved,and an open-loop structure antenna is proposed to solve its problem of poor in-band gain stability.To solve the problem of the narrow bandwidth of the five-grid array,based on a narrow-band unit with a rectangular loop and single stub,an antenna,with a rectangular loop and multiple open-ended stubs,is proposed.,extending the bandwidth from 4.6%of single-stub to 12.8% of five-stub.To achieve a higher gain,a five-stub extended array is further proposed,increasing the gain at the center frequency of 35GHz from 12.0dBi of the unit to 13.7dBi of the array.2.Research on miniaturized butterfly-loop antenna unit and high-gain arrayIt is difficult for the extended array to maintain the antenna aperture efficiency in a larger size.To solve the problem,a miniaturized unit and a high-gain array using a power splitter are studied.Focusing on the miniaturization of the rectangular-loop unit,a structure with a butterfly-loop and stubs on the two sides is proposed,realizing high gain within one wavelength.And multiple stubs are adopted to solve the problem of the gain stability of single-stub antenna.The simulation results show that the bandwidth of the five-stub unit is 12.8%,and a high gain of 10.9dBi is achieved under the electrical size of 0.88?₀×0.84?₀.To further increase the gain,a 2*2 array with a symmetrical structure is proposed.The simulated results show that this array realizes a high gain of 16.5dBi with the electrical size as 2.07?₀×1.90?₀ and a low-cross-polarization of 63dB.The five-stub butterfly-loop unit and the 2*2 array have been processed and measured,and the measured results are in good agreement with the simulated results.