A Simple PIFA-Based Tunable Internal Antenna for Personal Communication Handsets

A simple planar inverted F antenna (PIFA)-based tunable internal antenna is proposed for personal communication handset applications. The antenna can covers following frequency bands: DCS (1710-1880 MHz), PCS (1880-1990 MHz), UMTS (1900-2170 MHz), WiBro (2300-2390 MHz), WLAN (5.2 and 5.8 GHz), Bluetooth (2400-2480 MHz), and ISM band (2500-2700 MHz). Varactor diode is used to get tuning over the wide frequency range. Overall size of the antenna is 19.5 mm times 9.5 mm times 4 mm (0.741 cm³) makes it suitable for 4 G handsets and can be easily integrated inside commercial mobile handsets. The antenna was designed and optimized by using CST microwave studio program. Measured return losses (S₁₁) and radiation patterns of the antenna were carried on Anritsu 37377C vector network analyzer and in standard anechoic chamber room. Return loss of the antenna is within acceptable limit with reasonable radiation performance.