Antenna Booster Versus a Spiral Monopole Antenna for Single-Band Operation at 900 MHz

Abstract

The number of devices connected to the internet has grown exponentially through the last decade, making IoT and connection worldwide more possible every year, enabling an incredible number of applications. This calls for better and more efficient methods for designing wireless devices. An efficient and small antenna is needed to ensure connectivity, range, and battery life. Under these circumstances, antenna booster technology is proposed, which uses a tiny component called an antenna booster to excite currents in the ground plane of the IoT device. This allows the antenna booster to be as small as 12 mm × 3 mm × 2.4 mm, representing only ~λ/30 at 863 MHz. The antenna booster is matched across the frequency range using a matching network. The paper compares an antenna booster and a monopole antenna regarding bandwidth for a design using a 120 mm × 60 mm ground plane in the 863 MHz to 928 MHz frequency range. Afterwards, the same designs are analysed when the ground plane size changes from 20 mm × 30 mm to 200 mm × 200 mm using steps of 10 mm to determine which approach can be reused across 53.8% of the ground planes with S11 < −6 dB without making any changes to the antenna system; for contrast, the monopole antenna can be reused only 4.6%. In addition, the antenna booster features better total efficiencies of up to 2.3 dB. A physical prototype with the antenna booster validates the numerical analysis.