This paper presents the design of a rectangular microstrip line-fed patch antenna array with a centre frequency of 3.8 GHz for WiMAX and Unmanned Air Vehicle (UAV) applications. A single element, 1x2 and 2x2 microstrip rectangular patch antennas were designed and simulated in Computer Simulation Tool (CST) Microwave Studio environment. The results of designed antennas were compared in terms of Return Loss (S11 parameters), bandwidth, directivity, gain and radiation pattern. Compared to traditional microstrip antennas the proposed array structure achieved a gain and directivity of 13.2 dB and 13.5 dBi respectively. The antenna was fabricated using Rogers Duroid RT-5880 substrate with a dielectric constant r of 2.2 and a thickness of 1.574 mm respectively. The array antennas were measured in the laboratory using Vector Network Analyser (VNA) and the results show good agreement with the array antenna simulation.

Terahertz (THz) links will play a major role in high data rate communication over a distance of few meters. In order to achieve this task, antenna designs with high gain and wideband characteristics will spearhead these links. In this contribution, we present different antenna designs that offer characteristics better suited to THz communication over short distances. Firstly, a single-element antenna having a dipole and reflector is designed to operate at 300 GHz, which is considered as a sub-terahertz band. That antenna achieves a wide impedance bandwidth of 38.6% from 294 GHz to 410 GHz with a gain of 5.14 dBi. Secondly, two designs based on the same dipole structure but with added directors are introduced to increase the gain while maintaining almost the same bandwidth. The gains achieved are 8.01 dBi and 9.6 dBi, respectively. Finally, an array of 1×4 elements is used to achieve the highest possible gain of 13.6 dBi with good efficiency about 89% and with limited director elements for a planar compact structure to state-of-the-art literature. All the results achieved make the proposed designs viable candidates for high-speed and short-distance wireless communication systems.

International audienceIn this letter, a hexa-band printed monopole antenna composed of various L-shape radiating elements is presented for various wireless applications. The antenna is designed to fully cover the CDMA (870-890 MHz), GSM (900-1800 MHz), DCS (1710-1880 MHz), PCS (1900 MHz), LTE-E/LTE-D (2300-2800 MHz), and WLAN (2.45/5.8 GHz) frequency bands. The proposed antenna achieves a gain of 1.8 dB, 3.17 dB, 3.23 dB, and 5.82 dB at respective bands. Fabrication of the antenna is completed on Rogers RT-5880 high frequency laminate with a finite ground plane having a rectangular slot on the other side of the substrate. The antenna is realized via standard printed circuit board (PCB) technology and its performance is validated by measurements in terms of s-parameters and radiation characteristics

To fulfill the growing demands of high data rate communication, researchers are now focusing their concentration on the higher frequency bands lying in the THz region of the electromagnetic spectrum. With the advent of nano-components fabrication technology, researchers and scientists are now able to fabricate optical antennas at a nano-scale, in order to establishing a wireless commination link at THz frequencies, and find solutions to the general design problems associated with higher frequency antennas. Drawing inspiration from antennas at microwaves and radio-frequency technologies, optical antennas capture and couple free available electromagnetic radiation in the visible and infrared wavelengths in the same way as radio electric antennas do at the corresponding wavelengths. In this paper, authors review some of the state of the art optical antennas, their fabrication techniques and propose a novel dielectric nano antenna design. Comparing to the traditional radio-frequency antennas, an equilateral triangular dielectric resonator nano-antenna (ETDRNA) has been designed and simulated at 193.5 THz standard optical frequency. The proposed antenna is a planar structure having a multilayer geometry consisting of 'Ag' partial ground plane, a top and bottom 'SiO2' substrate and a 'Si' equilateral triangular as a dielectric fed by a 'Ag' nanostrip transmission line. The simulated antenna achieves an impedance bandwidth of 2.58% (192.5-197.3 THz) and an end-fire directivity of 8.6 dBi, covering all of the standard optical transmission window at C-band. Numerical demonstrations prove the efficiency of the nano-antenna at the frequencies of interest, making it a viable candidate for electromagnetic communication in optical applications and nanonetworks.