Beam Steering of Time Modulated Antenna Arrays Using Particle Swarm Optimization

yesIn this paper, a simple switching process is employed to steer the beam of a vertically polarised circular antenna array. This is a simple method, in which the difference resulting from the induced currents when the radiating/loaded element is connected/disconnected from the ground plane. A time modulated switching process is applied through particle swarm optimisation.Electronics and Telecommunication

Slotted Printed Monopole UWB Antennas with Tuneable Rejection Bands for WLAN/WiMAX and X-Band Coexistence

YesFour versions of the compact hexagonal-shaped monopole printed antennas for UWB applications are presented. The first proposed antenna has an impedance bandwidth of 127.48 % (3.1 GHz to 14 GHz), which satisfies the bandwidth for ultra-wideband communication systems. To reduce the foreseen co-channel interference with WLAN (5.2GHz) and X-Band systems (10GHz), the second and third antennas type were generated by embedding hexagonal slot on the top of the radiating patch. The integration of the half and full hexagonal slots created notched bands that potentially filtered out the sources of interference, but were static in nature. Therefore, a fourth antenna type with tuneable-notched bands was designed by adding a varactor diode at an appropriate location within the slot. The fourth antenna type is a dual-notch that was electronically and simultaneously tuned from 3.2GHz to 5.1GHz and from 7.25GHz up to 9.9GHz by varying the bias voltages across the varactor. The prototypes of the four antenna versions were successfully fabricated and tested. The measured results have good agreement with the simulated results.This work is carried out under the grant of the Fundacão para a Ciência e a Tecnologia (FCT - Portugal), with the reference number: SFRH / BPD / 95110 / 201

Compact Microstrip Antenna Design for Microwave Imaging

YesAn ultra-wideband microstrip antenna design is considered with respect to applications in breast cancer detection. The underlying design concept is based on ground penetrating radar (GPR). Simulated and measured prototype performance show excellent performance in the input impedance and radiation pattern over the target range from 4 GHz to 8 GHz. The 4 GHz to 8GHz frequency band for microwave imaging perform better in comparison with other microwave frequencies. The antenna also shows a reasonable uniform radiation performance in the broadside direction which contributes to the reduction of clutter levels, thus aiding the reconstruction quality of the final image

Frequency and Pattern Reconfigurable Antenna for Emerging Wireless Communication Systems

A printed and minimal size antenna having the functionality of frequency shifting as well as pattern reconfigurability is presented in this work. The antenna proposed in this work consists of three switches. Switch 1 is a lumped switch that controls the operating bands of the antenna. Switch 2 and Switch 3 controls the beam switching of the antenna. When the Switch 1 is ON, the proposed antenna operates at 3.1 GHz and 6.8 GHz, covering the 2.5–4.2 GHz and 6.2–7.4 GHz bands, respectively. When Switch 1 is OFF, the antenna operates only at 3.1 GHz covering the 2.5–4.2 GHz band. The desired beam from the antenna can be obtained by adjusting the ON and OFF states of Switches 2 and 3. Unique beams can be obtained by different combination of ON and OFF states of the Switches 2 and 3. A gain greater than 3.7 dBi is obtained for all four cases

A Capacitively loaded Antenna for use in Mobile Handsets

YesA tuneable slotted patch antenna design is presented and verified for use in the DCS, PCS and UMTS bands. The tuning circuit consists of two varactor diodes with some passive components, and is integrated fully with the r radiator patch, with the varactors occupying different locations over the slot. The tuning does not require any further modification to the patch or feed geometry. Good agreement is observed between the predicted and observed impedance bandwidth, return loss, gain and radiation pattern, throughout the range 1.70 GHz-2.05 GHz

The Compact Design of Dual-band and Wideband Planar Inverted F-L-antennas for WLAN and UWB Applications

yesTwo miniature low profile PIFLA antennas with a compact volume size of 30mm × 15mm × 8mm has presented in this paper. By applying the magnetic wall concept a reduced size dual-band and a wideband half PIFLAs for WLAN (2.4GHz/5.2GHz) and UWB applications are achieved. The dual-band antenna shows a relative bandwidth of 12% and 10.2% at ISM2400 and IEEE802.11a frequency bands respectively for input return loss less than 10dB. By carefully tuning the geometry parameters of the dual-band proposed antenna, the two resonant frequencies can be merged to form a wide bandwidth characteristic, to cover 3000MHz to 5400 MHz bandwidth (57%) for a similar input return loss that is fully covering the lower band UWB (3.1-4.8GHz) spectrum. The experimental and simulated return losses on a small finite ground plane of size 30mm × 15mm show good agreement. The computed and measured radiation patterns are shown to fully characterize the performance of the proposed two antennas.MSCR

Recent advances in antenna design for 5G heterogeneous networks

Ye

Secure Mutual Self-Authenticable Mechanism for Wearable Devices

YesDue to the limited communication range of wearable devices, there is the need for wearable devices to communicate amongst themselves, supporting devices and the internet or to the internet. Most wearable devices are not internet enabled and most often need an internet enabled broker device or intermediate device in order to reach the internet. For a secure end to end communication between these devices security measures like authentication must be put in place in other to prevent unauthorised access to information given the sensitivity of the information collected and transmitted. Therefore, there are other existing authentication solutions for wearable devices but these solutions actively involve from time to time the user of the device which is prone to a lot of challenges. As a solution to these challenges, this paper proposes a secure point-to-point Self-authentication mechanism that involves device to device interaction. This work exploits existing standards and framework like NFC, PPP, EAP etc. in other to achieve a device compatible secure authentication protocol amongst wearable device and supporting devices.

Microstrip Antenna for Microwave Imaging Application

yesA compact microstrip antenna design to be used in breast cancer detection is presented. The antenna consists of a radiating patch mounted on two vertical plates, fed by coaxial cable. A study is carried out on different parameters of the antenna. Simulation results show that the antenna possesses a wide bandwidth and this is confirmed experimentally. In experiments, a homogeneous dielectric box, having similar properties to human tissue is used to study the interaction of the antenna with tissue. Even without added matching medium or lumped loads there is good matching when the antenna is in contact with the tissue. Finally a two-element antenna array is investigated numerically, with promising results.MSCR