A novel concept of using fractal antenna with metamaterial and slot to achieve multiband operation is investigated. The antenna consists of an L-shaped slot, Sierpinski triangle (used as fractal) as the radiating part and metamaterial circular split ring resonator (SRR) as the ground plane. The introduction of metamaterial in the ground plane makes the antenna operate at 3.3 GHz (middle WiMAX). The etching of Sierpinski triangle and L-shaped slot in the radiating monopole perturbs the surface current distribution; thereby increasing the total current path length which tends the antenna to further operate at 5.5 (upper WiMAX), 7.3 (satellite TV) and 9.9 GHz (X-band), respectively. The extraction of medium parameter of a circular SRR through waveguide medium is discussed in detail. The antenna has a compact dimension of 0.33λ0 × 0.27λ0 × 0.01λ0 = 30 mm × 24.8 mm × 1.6 mm, at a lower frequency of 3.3 GHz. Under simulation, antenna operates at 3.3, 5.5, 7.3 and 9.9 GHz with S11 < −10 dB bandwidth of about 5.9% (3.24–3.44 GHz), 5.6% (5.31–5.62 GHz), 7.3% (6.99–7.52 GHz) and 3.02% (9.78–10.08 GHz), respectively. In measurement, antenna exhibit resonances at 3.1, 5.52, 7.31, 9.72 GHz with S11 < −10 dB bandwidth of about 3.5% (3.04–3.15 GHz), 5.01% (5.44–5.72 GHz), 13.2% (6.76–7.72 GHz) and 5.77% (9.42–9.98 GHz), respectively. Good impedance matching and stable radiation characteristics are observed across the operational bandwidth of the proposed configuration.

A concept of using slots both in the radiator and in the ground to miniaturize an ultrawideband (UWB) antenna in order to operate at multiband is demonstrated. Initially, a miniaturized circular UWB antenna is designed which results in about 53.5% reduction in total volume and about 46.6% in the active patch area, in comparison to the conventional UWB antenna. To reconfigure the proposed UWB antenna to operate in multiband applications, slotted ground approach is used. The slots in the ground plane of the proposed design affects the surface current distribution due to which the designed antenna operates at 3.7 (middle WiMAX), 5.7 (upper WiMAX), and 7.5 GHz (X‐band) with −10 dB reflection coefficient bandwidth of about 5.3% (3.64–3.84 GHz), 5.5% (5.64–5.96 GHz), and 3.7% (7.44–7.72 GHz), respectively. The proposed configuration is compact in size with a total area of only 0.26λ0 × 0.21λ0 = 30 × 24.8 = 283.3 mm,2 at lower resonating band of 2.6 GHz. The designed multiband structure yields good impedance matching, acceptable gain and stable radiation characteristics both in xz and yz plane, across their operational bandwidths.

This paper presents a compact 55× 20 mm2 wideband multi-input-multi-output (MIMO) antenna. The proposed structure consists of two antenna elements excited using CPW feeding technique and is printed on a low cost and easily available FR4 substrate. In the proposed MIMO design, the first antenna at port 1 is fixed in its position and orientation while, the second antenna at port 2 is placed in six different orientations by keeping the overall dimension constant. The observation is made on the variation in the insertion loss as the orientation of the second antenna is altered. With this analysis, the orientation of second antenna element giving the least interference and insertion loss is proposed, and all the parameters are studied. The proposed design exhibits an average peak gain greater than 2.8 dBi, envelope correlation coefficient (ECC) less than 0.0001, insertion loss less than -38 dB and stable radiation patterns over the entire wide bandwidth. The antenna operation (i.e. |S11| and |S22|<-10 dB) ranges from 4.1 to 6.4 GHz at port 1 and 4.35 to 6.5 GHz at port 2, thereby making the antenna suitable for Wireless Local Area Network (WLAN) and Wireless Fidelity (Wi-Fi) applications.

A compact bandwidth enhanced antenna using metamaterial single Rectangular Split Ring Resonator (RSRR) for WLAN/WiMAX/Satellite applications is presented. As the wireless modules continue to shrink, there exists a drastic demand for a compact antenna. In addition to this, the effective integration of an antenna in wireless devices acts as stand-alone implement to mitigate the effects of noise fading. The presented antenna consists of three metamaterial single RSRR and a coaxial feed. Compactness in the design is achieved with the help of coaxial feeding technique. The etching of Upper metamaterial single RSRR creates a resonance at 6 GHz (WLAN) band, with S11 < -10 dB bandwidth ranging from 5.46 – 6.7 GHz (1240 MHz). Bandwidth enhancement in the proposed design at 6 GHz, is accomplished by the two metamaterial single RSRR placed at the left and ride side of the radiating patch, just below the upper RSRR. Due to the placement of two lower RSRR the bandwidth of the proposed antenna gets enhanced from 1240 to 3120 MHz. The antenna has a size of only  20 x 18 x 2.54 mm3 . The antenna exhibits bi-directional and Omni-directional radiation characteristics in E and H-plane, respectively. Compact size, good impedance matching, stable radiation pattern and radiation efficiency greater than 95% are observed across the operational bandwidths of the designed antenna. The aforementioned advantages make the proposed antenna suitable for WLAN/WiMAX/Satellite applications.

This paper presents an innovative method for the design of a triple band meta-mode antenna. This unique design of antenna finds application in a particular frequency band of WLAN and WiMAX. This antenna comprises of a square complimentary split ring resonator (SCSRR), a coaxial feed, and two symmetrical comb shaped split ring resonators (CSSRR). The metamaterial unit cell SCSRR independently gains control in the band range 3.15–3.25 GHz (WiMAX), whereas two symmetrical CSSRR unit cell controls the band in the ranges 3.91–4.01 GHz and 5.79–5.94 GHz (WLAN). This design methodology and the study of the suggested unit cells structure are reviewed in classical waveguide medium theory. The antenna has a miniaturized size of only 0.213λ0 × 0.192λ0 × 0.0271λ0 (20 × 18 × 2.54 mm3, where λ0 is the free space wavelength at 3.2 GHz). The detailed dimension analysis of the proposed antenna and its radiation efficiency are also presented in this paper. All the necessary simulations are carried out in High Frequency Structure Simulator (HFSS) 13.0 tool.