Design of an Impedance-Matched Horn Antenna with Enhanced Directivity Using Conformal Transformation Optics

In this work, conformal transformation optics is employed to enhance the directivity of a horn antenna. The phase error at the horn’s aperture is mitigated using a dielectric graded-index lens designed by the conformal transformation. The design not only leads to a negligible phase error at the aperture but also has an excellent impedance match to the vacuum. Simulation results show that for a typical horn antenna with length and aperture width equal to ten wavelengths, our method can enhance the directivity more than 5 dB.