Bow-Tie Microstrip Antenna Design

In this paper, the bow-tie microstrip antennas have been designed with two different angles of 40° and 80°. An investigaton on the effect of the angle to the return loss and radiation patterns had been carried out. The impedance matching network with the niicrostrip transmission line feeding was used in this study. Simulation and measurement results for the return loss and radiation patterns were presented

Triple-band printed dipole tag antenna for RFID

In this paper, a triple-band printed dipole tag antenna is proposed for Radio Frequency Identifcation (RFID). The triple- band printed dipole antenna is designed to operate at 0.92 GHz, 2.45 GHz and 5.8 GHz using Computer Simulation Technology (CST) software. In order to achieve triple-band operation, the proposed antenna contains two branch elements, which act as an additional resonator. The designed antenna is fabricated using Taconic RF-35 substrate with a dielectric constant ("r) of 3.5 and thickness (d) of 0.508 mm. The antenna's parameters for triple-band operation are investigated and discussed. Then, this fabricated antenna is integrated with a UHF microchip to become a passive UHF tag. This tag is tested by measuring the reading distance and it is found that the proposed tag can be used for RFID application

Textile Diamond Dipole and Artificial Magnetic Conductor Performance under Bending, Wetness and Specific Absorption Rate Measurements

Textile diamond dipole and Artificial Magnetic Conductor (AMC) have been proposed and tested under wearable and body centric measurements. The proposed antenna and AMC sheet are entirely made of textiles for both the substrate and conducting parts, thus making it suitable for wearable communications. Directive radiation patterns with high gain are obtained with the proposed AMC sheet, hence minimizing the radiation towards the human body. In this study, wearable and body centric measurements are investigated which include bending, wetness and Specific Absorption Rate (SAR). Bending is found not to give significant effect to the antenna and AMC performance, as opposed to wetness that yields severe performance distortion. However, the original performance is retrieved once the antenna and AMC dried. Moreover, notable SAR reduction is achieved with the introduction of the AMC sheet, which is appropriate to reduce the radiation that penetrates into human flesh

An Electronically Reconfigurable Patch Antenna Design for Polarization Diversity with Fixed Resonant Frequency

In this paper, an electronically polarization reconfigurable circular patch antenna with fixed resonant frequency operating at Wireless Local Area Network (WLAN) frequency band (2.4-2.48 GHz) is presented. The structure of the proposed design consists of a circular patch as a radiating element fed by coaxial probe, cooperated with four equal-length slits etched on the edge along x-axis and y-axis. A total of four switches was used and embedded across the slits at specific locations, thus controlled the length of the slits. By activating and deactivating the switches (ON and OFF) across the slits, the current on the patch is changed, thus modifying the electric field and polarization of the antenna. Consequently, the polarization excited by the proposed antenna can be switched into three types, either linear polarization, left-hand circular polarization or right-hand circular polarization. This paper proposes a simple approach that able to switch the polarizations and excited at the same operating frequency. Simulated and measured results of ideal case (using copper strip switches) and real case (using PIN diode switches) are compared and presented to demonstrate the performance of the antenna

Enhancement of finger vein image using multifiltering algorithm

Finger vein images are prone to various noise due to imperfect capturing device used. As a result of transmission errors, pixel elements in the capturing sensors malfunction, memory location fault and analog-to-digital conversion time errors, noise could also occur. Using single filtering method cannot give a satisfactory result of the vein image. Hence, this paper proposed a multifilter algorithm that's capable of locating the region of interest of the vein and de-noise the image from corrupted noises while the edges of the image are kept intact. The algorithm does not need to have prior knowledge of the image and the corrupted noise. The fusion of simple mask filter algorithm and mixed filter algorithm of Median and Wiener filters is used. Experimental results coded in MATLAB using SDUMLA-HMT finger vein database show that the proposed algorithm is feasible and efficient

Single-, Dual- and Triple-band Frequency Reconfigurable Antenna

The paper presents a frequency reconfigurable slot dipole antenna. The antenna is capable of being switched between single-band, dual-band or triple-band operation. The antenna incorporates three pairs of pin-diodes which are located within the dipole arms. The antenna was designed to operate at 2.4 GHz, 3.5 GHz and 5.2 GHz using the aid of CST Microwave Studio. The average measured gains are 1.54, 2.92 and 1.89 dBi for low, mid and high band respectively. A prototype was then constructed in order to verify the performance of the device. A good level of agreement was observed between simulation and measurement

Optimum transmitter receiver ratio for maximum wireless energy transfer

Due to high demand of using cordless mobile device, the interest in wireless energy transfer (WET) has been growth intensively. This paper presented a method to obtained optimum transmitter receiver ratio for maximum performance of WET system using different initial antenna size at various distance. An optimized algorithm has been developed to determine the optimum ratios that yield the highest wireless transfer efficiency (WTE) at near field communication (NFC) frequency, 13.56MHz. 30mm × 30mm single square loop antenna is used as initial size of both transmitter and receiver using FR4 with operating distance = 50mm. Operating distance and initial size of the antenna will be varied and the effect to the WTE will be studied using Matlab, verified using Microsoft Studio CST. At distance = 50mm and initial size of the antenna = 30mm × 30mm, optimum transmitter to receiver ratio equal to 1:3 is obtained. The pattern of optimum transmitter receiver ratio between Matlab and CST has met an agreement. This research limited to integer transmitter receiver ratio used only and no decimal number being involved in magnify the transmitter size

Bandwidth enhancement of rectangular dielectric resonator antenna using circular slot coupled technique

This article presents a technique to enhance the bandwidth of a rectangular dielectric resonator antenna using a circular slot. The structures are designed and simulated using CST Microwave Studio software, and it is found that the circular slot exhibits a bandwidth of 36.44% (0.92-1.33 GHz). The circular slot is compared with the rectangular slot. It is shown that the rectangular slot produces a bandwidth of 6.39% (1.06-1.13 GHz). Both structures exhibit similar radiation patterns with slightly different gains at 3.10 and 3.25 dBi. The bandwidth is enhanced more than five times using the circular slot, compared to the rectangular slot

Wide to multiband elliptical monopole reconfigurable antenna for multimode systems applications

Wideband-multiband reconfigurable elliptical monopole antenna is investigated in this paper. By having conventional elliptical monopole antenna, wideband operating frequency is obtained. With the combination of dual pairs of slotted arms and a band-pass filter on the ground plane of the elliptical monopole, multiband is achieved. Dual-band operating frequencies at 1.6 GHz and 2.6 GHz while wideband operates from 3.35 GHz to 9 GHz. Therefore, wide range of wireless communication systems is obtained from the proposed antenna to support the multiband mode (i.e. GPS and LTE) and UWB systems. Frequency reconfigurable is achieved by controlling the switches integrated on the antenna structure. Simulated results of reflection coefficient, radiation patterns and gain performance are presented. The proposed antenna design is suitable candidate for different wireless communication applications

Dual element MIMO planar inverted-F antenna for 5G millimeter wave application

This work presents a 28 GHz Dual Element Multiple Input Multiple Output (MIMO) Planar Inverted-F Antenna for millimeter wave 5G mobile terminal. The antenna design employs PIFA design concept as it is a common antenna type use for mobile phone as it provides wide bandwidth and good performance. The antenna design begins with a characterization of the single element PIFA design and then extended to Dual Element MIMO PIFA design. The single element PIFA design is enhanced to MIMO design by extending the ground plane and locate the second PIFA at the other end. Isolation between the antenna elements of the MIMO PIFA is analyzed by varying the gap distance between the antenna elements. The result for Envelope Correlation Coefficient, Diversity Gain and Multiplexing Efficiency is also presented. The simulation computed using Computer Simulation Technology (CST) Microwave Studio software