Loss quantification for microstrip reflectarray: Issue of high fields and currents

This paper characterizes the dielectric loss and conductor loss phenomenon which occurs in printed reflectarray elements performing HFSS simulations and waveguide measurements. The variable size patches reflectarray design was chosen to investigate the loss phenomenon. It was seen that the dielectric loss which occurs due to the strong E-fields in the substrate region and the copper loss which occurs due to the high currents on the top surface of the patch is significant for thin substrates close to resonance but these losses are negligible away from resonance. These losses were also dependent on the thickness of the substrate and decreased by increasing the substrate thickness. Waveguide measurements were conducted to measure the return loss and reflection phase for the different substrate thicknesses and showed good agreement with the simulation model.