This article concerns the design of a new quad-band monopole antenna with a specific configuration and reduced size. The antenna design is based on a single step meander-line parasitic structure, parasitic stubs, and double inverted L-shaped defected microstrip structure units on the top side of the substrate, and double rectangular-shaped defected ground structure units along with partial ground plane on the bottom side. This design procedure allows to achieve quad-band characteristics and improve the impedance matching. The fabricated antenna prototype with overall dimensions of (0.24λ0 × 0.17λ0 × 0.013λ0) is operating at 2.55, 3.65, 4.65, and 5.8 GHz with fractional bandwidth about 7.7, 12.84, 9.23, and 12.8%, respectively. The antenna exhibits an omnidirectional and a monopole like radiation patterns in the H- and E-planes, respectively, with suitable gains between 2.1 and 3.75 dBi. The measurement results are in good agreement with simulation values, which indicates that the proposed antenna design is suitable for WiMAX, LTE B7 (2.52–2.75 GHz), Sub-6 GHz 5G (n77) (3.39 – 3.87 GHz), Sub-6 GHz 5G (n78) (4.4–4.86 GHz), and WLAN, LTE B46 (5.1–5.82 GHz) wireless applications.

In this paper, a compact tri-band asymmetric coplanar strip (ACS)-fed meander-line antenna for wireless communications is proposed. Two inverted-L-shaped resonators are added to a simple meandered radiator for standard tri-band operation. Parametric studies indicate that operating frequencies of the proposed antenna are determined by the dimensions of the two inverted-L-shaped resonators. The measured results show that the proposed antenna can achieve three frequency bands; i.e. 1.48–1.63, 2.25–2.48, and 4.22–6.0 GHz. These bands can successfully cover the global positioning system L1, wireless local area network (WLAN), and HIPERLAN/2 operation bands, respectively. The proposed antenna exhibits good radiation patterns with reasonable gain and high radiation efficiency across the operating bands. In addition, the proposed antenna has compact size and simple feeding scheme, which make it suitable to be integrated within the portable device for wireless communications.