The design and analysis of meta-material inspired loaded monopole antenna for multiband operation are reported. The proposed antenna consists of multi resonators inspired from half mode composite right/left handed cells, which has a simple structure, compact size, and provides multiband functionalities. As a proof of concept, a triple band antenna covering all possible WiMAX operating bands, has been designed, fabricated, and characterized. The hosting monopole patch itself generates resonance for 3.3–3.8 GHz band, whereas the loaded metamaterial cells add extra resonance frequencies. The loading of two resonator cells introduces two extra resonances for 2.5–2.7 GHz and 5.3–5.9 GHz bands, respectively. The antenna's operating principle and design procedures with the aid of electromagnetic full wave simulation and experimental measurements are presented. The antenna has good omnidirectional patterns at all three bands. The monopole patch size is 13.5 × 6.5 mm2 and the whole antenna size (including the feed line) is 35 × 32 mm2. Compared with conventional single band microstrip patch radiator, the radiator size of this antenna is only 8.5% at 2.5 GHz, 17% at 3.5 GHz, and 37% at 5.5 GHz.

This paper proposes a novel wideband to concurrent tri-band frequency reconfigurable microstrip antenna. The frequency reconfiguration is achieved by using a pair of PIN diodes in the antenna feed line to switch the antenna either in wideband mode or in concurrent tri-band mode. In order to improve the bandwidth and gain of the antenna for wideband operation, the properties of J-K inverter and split ring resonators are exploited. To demonstrate the versatility of this concept a prototype is fabricated and tested here. The tested results in wideband mode shows that the proposed antenna operates from 3.58 to –3.82 GHz, which is 4.08 times larger than the bandwidth of a simple microstrip patch antenna. In the concurrent tri-band mode frequency tuning is done by microstrip open stub at 1.5 GHz, 1.9 GHz, and 3.5 GHz. Gain of the proposed antenna is better than 2.7 dB in wideband mode and 2.7 dB in concurrent tri-band mode.

A new planar microstrip-fed monopole ultra-wideband (UWB) antenna with dual notched bands has been presented. By employing a simple dual-mode resonator with two symmetrical outer high-impedance lines beside the microstrip feed line of the proposed UWB antenna, two controllable rejection bands with high-frequency selectivity are created. The parametric studies of the proposed structure are explored for the dual band-notched operating mechanism. Finally, the experimental results, including return losses, radiation patterns, and peak gains are shown, declaring that the proposed antenna has good impedance matching performance and radiation pattern properties.

An ultra-wideband (UWB) log-periodic dipole array (LPDA) antenna inkjet-printed on a 0.5 mm thick photo paper substrate is presented. The overall size of the LPDA antenna is 130 × 60 mm2. The LPDA antenna exhibits stable input-impedance characteristics and a consistent end-fire radiation pattern over the whole operating band of 2.2–11 GHz. Fulfilling the need of high-gain flexible antennas for UWB, a highly directive measured gain of 9.5 dBi on a paper substrate makes it an excellent candidate for flexible wireless devices.

Fresnel Zone Plate lens (FZPL) antennas working in the V and W band are reported in this paper with half and quarter phase correction respectively. A low cost and straightforward technological process is used to manufacture the dielectric lenses using only one foam material where the dielectric constant is controlled. Simulation and measurement results are in good agreement that confirms the viability of such a process to fabricate inhomogeneous structures. Good loss efficiency of 73 and 55% are obtained at 60 and 85 GHz respectively with the two different FZPL designs.

A novel radio frequency identification tag antenna is composed of a resonant open-slot exciter and a dipole-type ground radiator. For a conjugate match to the Alien Higgs-4 chip impedance of 8−j149 Ω at 925 MHz, a quarter wavelength open-slot resonator embedded at the center of the dipole-type ground plane (130 × 18 mm2) was investigated and fabricated. Simple size adjustments and various loaded inductor of the open-slot resonator allow for easy control of the tag antenna resistance and inductive reactance, from which the chip impedance requirement can be easily obtained. The read range of the prototype antenna attached on a foam in the free space can reach more than 9 m, which has been tested for a radio frequency identification reader with 4.0-W of effective isotropic radiated power. Measurement data are in good agreement with simulation results.

A circular patch antenna with wide impedance bandwidth and monopolar radiation pattern for indoor wireless communication is proposed and analyzed in this paper. The antenna is a combination of circular patch and four capacitive feeds. By incorporating a cross-connected shorted conducting strip over the circular patch, the proposed antenna provides an enhanced impedance width of 65.4%, ranging from 1.46 to 2.88 GHz. Four capacitive feeds improve the design flexibility and make the ripple of horizontal radiation pattern less than 3 dB. A prototype of the proposed structure has been fabricated and measured. Both the simulated and measured results show that the proposed design has a stable monopolar radiation pattern over a wideband frequency range and a peak gain of 5.0 dBi, which can be widely applied for indoor wireless communication such as GSM1800, CDMA2000, WCDMA, and TD-LTE systems.

A novel small embedded long-term evolution/wireless wide area network (LTE/WWAN) antenna integrated with the keyboard ground plane in a laptop computer is presented. The antenna is installed on a notched region (40 × 8 mm2) of the keyboard ground plane at a distance of 10 mm from the laptop computer hinge. A coupled-fed loop antenna was used because of its suitability for integration with the ground plane and achieving wide operating bands. This antenna can not only be configured to have a compact configuration but also be designed to excite several resonant modes of the hinge slot between the display ground plane and the keyboard ground plane. The proposed antenna comprises a hook-shaped strip and a shorted strip, which together form a coupled-fed loop that not only has a compact size when printed on a 0.8-mm-thick FR4 substrate 40 × 8 mm2 in size but also provides eight-band LTE/WWAN operation. The proposed antenna can cover LTE/WWAN operation in the 698–960 and 1710–2690 MHz bands. Details of the antenna structure are provided here. The proposed antenna was fabricated and tested, and measurement and simulation results are presented. The measured antenna efficiency was approximately 45–80% in the lower band and approximately 52–75% in the upper band.