Design of a Smart Watch Tri-Band GPSBluetooth-WiFi5 Square Loop Antenna

A square loop antenna that works for three frequency bands is considered. The three frequency bands are L1 GPS (1.575 GHz), Bluetooth (2.400 GHz to 2.483 GHz), and WiFi5 (5.150 GHz to 5.850 GHz). This antenna has dimensions of 36 mm by 45 mm by 5 mm. It is on top of a 0.4 mm thick dielectric substrate that has copper cladding on one side. The square loop itself is composed of thin copper sheets with a thickness of 0.3 mm. The antenna is designed to have a compact size for potential use for smart watches. It has two shorting strips that connect the ground plane to the loop itself at two different locations. There is also an air gap in the loop. The shorting portions and the air gap create the operating bands in the desired frequencies.