Miniature Dual-Band Meander-Line Monopole Chip Antenna With Independent Band Control

A dual-band monopole chip antenna with an overall size of 5 x 3 x 2.1 mm(3) is investigated for 2.4/5.2/5.8 GHz WLAN applications. The chip antenna has three substrates with four copper layers in total. It deploys a modified nonuniform folded meander line and capacitive loading patches to reduce the antenna size. A fundamental monopole mode and a higher order mode are excited to obtain the 2.4 GHz (2.40-2.48 GHz) and 5 GHz (5.150-5.350 GHz and 5.725-5.875 GHz) WLAN bands, respectively. The lower and upper bands can be independently controlled by the widths of the meander lines on the first and third layers, respectively. Aprototype was fabricated and measured to verify the idea. Areasonable agreement between themeasured and simulated results is observed. The measured 10 dB impedance bandwidths of the lower and upper bands are 5.3% (2.38-2.51 GHz) and 19.3% (5.14-6.24 GHz), respectively, fully covering the 2.4/5.2/5.8 GHz WLAN bands. The measured efficiency of the chip antenna is higher than 60% for the two bands.