Ground Clearance in Smartphone Antennas

This work investigates the effect of ground clearance on achievable smartphone antenna performance considering both industrial and scientific aspects. In addition to parametric studies, example antennas with small and large clearances are designed to visualise the design trade-offs in terms of size, bandwidth, and efficiency. Present antennas need a clearance of 5-6 mm to cover the low band at 698-960 MHz with an efficiency of -3 dB, whereas 3 mm is sufficient for comparable high-band performance.