Chassis engineering to enlarge the bandwidth for GSM-450 application

This paper presents a new solution to enlarge the bandwidth of single ended antenna placed on a ground plane with a small size (<; λ/4) compare to the wavelength. By adding a metallic extension on the chassis, the fundamental resonance mode of the chassis is decreased to the desired frequency and coupled with the antenna frequency resonance to increase the bandwidth. A design for the GSM-450 standard is proposed to verify assumption and simulation show that the bandwidth is enlarged by a ratio of 6 using this method.