Design and optimization of a C-Band lens horn for scatterometer calibration

Abstract

In this paper the design and optimization process of a scatterometer calibration antenna is presented. The solution consists in a septum polarizer and a high gain Potter horn with exceptionally low axial ratio (0.2 dB) and low SLL at 5.3 GHz. To obtain a compact design, the horn length has been reduced and a dielectric lens has been designed to correct the horn phase error. Several types of lenses are presented and analyzed, and their effects on the radiation pattern and aperture fields are discussed. The discontinuity in electric permeability produced by the lens degrades the horn adaptation. To solve this issue, impedance matching transformers are designed and simulated in order to fulfill the mentioned specifications.