A Novel Quad-Band ACS-FED Antenna

A compact quad-band asymmetric coplanar strip (ACS) fed printed monopole antenna, is presented in this paper. It consists of composite right/left-handed transmission line (CRLH-TL) unit cells and open-ended stub, which improves the impedance bandwidth of the zero-order mode (5.5 GHz), first-negative-order mode (4.4 GHz) and second-negative-order mode (3.5 GHz), as well as generate a new resonant mode at 2.4 GHz. The antenna occupies a very compact size of 21.6×12 mm². Simulated and measured results show the antenna´s good properties of return losses less than -10 dB, omnidirectional radiation patterns and high peak gains in the quad frequency bands. The proposed antenna is a good candidate for modern wireless communication systems.