A Tri-mode Hybrid Antenna for Quad-band Applications

|This paper presents a coplanar waveguide (CPW)-fed tri-mode hybrid antenna that is suitable for quad-band applications. The antenna design is compact, measuring only 30 (cid:2) 30 mm 2 , and consists of a zeroth-order resonator (ZOR) antenna, a torch-shaped monopole antenna, and a T-shaped slot antenna. The most signi(cid:12)cant feature of this design is its ability to provide three independent working modes, making it a hybrid antenna. By incorporating a Composite Right/Left-Handed Transmission Line (CRLH-TL) unit cell, the (cid:12)rst mode is excited as a ZOR antenna, corresponding to the lowest resonance at around 1.57 GHz. The second mode relies on the torch-shaped monopole antenna with two resonances at about 2.5 GHz and 3.5 GHz. The third mode employs the T-shaped slot antenna with a resonance at around 5.5 GHz. Experimental results demonstrate that the proposed antenna exhibits a wide and multi-band behavior with impedance bandwidths of 60 MHz (1.56{1.62 GHz), 210 MHz (2.30{2.51 GHz), 370 MHz (3.40{3.77 GHz), and 1100 MHz (5.05{6.15 GHz). This antenna can not only support the current GPS/WLAN/WiMAX systems but can also be considered as one element of a multiple-input-multiple-output (MIMO) antenna array for the (cid:12)fth-generation (5G) mobile communication in the sub-6 GHz frequency range.