M. F. Ismail

The Investigation of PIN diode switch on reconfigurable antenna

The investigation and simulation of PIN diode as a switch on reconfigurable antenna are described in this paper. The simulation of the PIN diode model is constructed on CST Simulation tools with the integration of single patch antenna. The radial stub biasing circuit is used for fabrication with the antenna. Three different locations of PIN diode with radial stubs biasing circuit are investigated and analyzed. The result shows the separation of biasing circuit and antenna give a better performance in term of return loss and current distribution.

Circular Polarization Fractal Koch microstrip patch Antenna using single-fed EM coupled ring Resonators

This paper describes the design and analysis of a Circular Polarization Fractal Koch Antenna using single-fed electromagnetic (EM) coupled ring resonator at 2.4 GHz. By applying fractal Koch, the proposed antenna size is reduced about 5% compared to the square patch using single-fed EM coupled ring resonator antenna. The simulation process has been done by CST software. Simulation as well as measurement results with antenna design have been presented and it shows that a good agreement in term of return loss and axial ratio. The antenna exhibits a bandwidth of 1.65% at −10dB return loss and 3dB Axial Ratio (AR) bandwidth of 0.78% with gain of 5.97dBi

Compact circularly polarized textile antenna

The performance of a compact circular polarization (CP) textile antenna is presented. The design is based on the traditional CP rectangular truncated patch antenna. Four slits are introduced at every edge of the rectangular truncated patch antenna to make it compactness. Simulated results show that the proposed antenna can have an antenna reduction of about 18% compared to the traditional one. A good bandwidth (2.40 GHz-2.50 GHz) with axial ratio (AR) bandwidth (2.41 GHz-2.44 GHz) and gain of 5.70 dB is presented. This antenna is suitable for application of wireless monitoring communication system and Wireless Local Area Network (WLAN) application.

Circularly polarized textile antenna with bending analysis

A slotted circular polarization (CP) textile antenna is designed for radio frequency (RF) energy harvesting system. The antenna composed a circular patch with cross slot at the centre of the patch. a good bandwidth (2.22 GHz-2.59 GHz), axial ratio (2.38 GHz-2.45 GHz) with directivity gain of 7.34 dBi is presented. This paper also presents the performance of the antenna in bending condition to suits with application of rectenna for energy harvesting system and antenna for monitoring system.

Wide-band rectangular dielectric resonator antenna design

In this paper a novel design procedure to obtain wideband and small size dielectric antennas using high dielectric constant material is described. It is shown that by selecting the resonator shape and creating a notch on the dielectric resonator, it is possible to design rectangular dielectric resonator antenna which compact size and wide frequency coverage. Simple formulas are presented to illustrate the design procedure and allow a quick dimensioning of the antenna. Utilizing the proposed configuration and skillfully varying its aspect ratio, an appropriate structure is obtained that illustrates more than 47.03% impedance bandwidth (for VSWR< 2) at 4.39 to 7.09GHz frequency band.

Design and analysis of metamaterial antenna using Triangular resonator

In this paper, a metamaterial antenna consisting of Triangular resonator (TR) and a thin wire (TW) is proposed. The antenna is excited through a single unit cell left Handed Materials (LHM) which act as the main radiating element via coplanar waveguide (CPW) transmission line. The Left Handedness of the unit cell is investigated and verified. The simulated return loss shows that a bandwidth of 58% is achieved over a frequency band of 6.42-11.23 GHz at a return loss of -10dB. The maximum gain of 4.45 is obtained at a frequency of 10.32GHz. Simulated and measured return loss shows an agreement while the radiation pattern is Omnidirectional.

Miniature dual-fed circularly polarized antenna with slotted ground plane

A new configuration of a dual-fed square patch circular polarization (CP) antenna for WiMAX and energy harvesting application is proposed. The normal dual-fed CP is designed at operating frequency of 2.8 GHz and after introducing a slotted ground plane underneath the radiating patch, the operating frequency is reduced to 2.5 GHz while maintaining the patch size and polarization performance. It was found that, good return loss from 2.5 GHz-2.6 GHz (3.2 %) and axial ratio (AR) bandwidth of 1.22 % with gain of 3.02 dB are achieved by using this technique. Simulated and measured results are used to demonstrate the performance of the antenna.

Frequency reconfigurable square ring slot antenna

Frequency reconfigurable square ring slot antenna is presented. The designed antenna comprises of two small rectangular ring slot and a square ring slot fed by a microstrip transmission line. Two switches are placed between the square and rectangular ring slot which provides frequency reconfigurability. The designed antenna is capable of reconfiguring to three frequency bands which at 1.9 GHz, 2.1 GHz and 2.3 GHz. The simulated gain and radiation pattern, together with the return losses, are discussed. The designed antenna has the potential to be used for GSM, 3G and Wimax wireless communication system.

Dual-fed circular polarization compact array antenna

The dual-fed circular polarization (CP) square patch compact array antenna is proposed. The antenna is design at 2.9 GHz geometry with dual slot is placed underneath of radiating patch at ground plane to reduce the operating frequency to 2.4 GHz while maintaining the size and CP condition. The antenna is fabricated on FR-4 substrate. It was found that, good return loss from 2.38 GHz-2.6 GHz (8.84 %) and axial ratio (AR) bandwidth of 2.51 % with gain of 5.2 dB are achieved by using this technique. Simulated and measured results are used to demonstrate the performance of the antenna. This antenna is suitable for application of Wireless Local Area Network (WLAN) and energy harvesting system.

Investigation the performance of Koch fractal multiband textile antenna for on-body measurement

Kochs fractal multiband textile antennas are investigated for finding the best placement of antenna on the body. Two different conducting materials as the radiating element are investigated in this work; copper tape and SHIELD IT fabric. The substrate of antenna is a denim textile, which has permittivity of 1.7 and loss tangent of 0.025 at 2.5 GHz. This paper describes the investigation of antenna performance on the human body, which is the chest, the forearm, the arm and the back side of bodies. The comprehensive on-body measurements are conducted with two conditions; human with shirt and human without shirt. The experiment shows the copper tape material is better than SHIELD fabric. The suitable placement of the multiband antenna is on the backside of the body with vertical position.