Dual Layer Microstrip Refflectarray Composed of Two Stacked Arrays with Minkowski and Square Shaped Radiating Element

Abstract

A dual layer microstrip reflectarray composed of two stacked arrays with Minkowski and square patches of variable dimension is presented. The reflection phase coefficients on the reflector surface is achieved by tuning the dimensions of the patches. This technique is to broaden the bandwidth and to extend the reflection phase range compare to a conventional single layer reflectarray. From the simulation results of a unit cell composed of two stacked arrays of Minkowski and square patch showed that, 415° reflection phase range is achieved and lower insertion loss which is lower than 0.9 dB. Base on the simulated reflection phase coefficient, a dual layer microstrip reflectarray antenna with Minkowski and square radiating shape elements have been design and model using commercially available computer models of CST Microwave Studio. The reflectarray has been constructed using Taconic RF-35 substrate. From the radiation pattern at 11 GHz frequency, it shows that the HPBW of 4.7º in both plane, a side lobe level (SLL) of –17 dB and a maximum directivity of 26.1 dBi.