Aperture-Coupled Koch Fractal on-Chip Antennas for 60 GHz ISM Band

This paper presents Koch fractal aperture-coupled patch antennas operating in industrial scientific and medical band at 60 GHz (57 GHz to 64 GHz), for on-chip application. This work is the continuation of the development of aperture-coupled antennas with aperture and patch element built in 2 μm-thick aluminum lying on two layers of silicon with a height of 200 μm. The use of Koch fractal allowed the development of aperture-coupled antennas of greater perimeter with more metal in the patch elements, which promoted an increase in the gain. The observed gain for Koch fractal level 2 was of 10.55 dBi, with a bandwidth of 7.23 GHz, covering the ISM 60 GHz Band, and an increase of less than 10% in total patch dimension. For Koch fractal levels 0 (square), a polarization close to circular was achieved, with an axial ratio less than 6 at resonant frequencies.