N. A. Zainuddin

Investigation of dual and triple meander slot to microstrip patch antenna

A dual and triple microstrip meander slot antenna is presented for Wireless Local Area Network (WLAN) application. The antenna also has the potential to be used as the receiving antenna in an energy harvesting system. The proposed antenna comprises a rectangular microstrip patch element embedded with meander slots. The parametric study is performed to investigate the characteristic of microstrip patch antenna with double meandered slots compared to the same microstrip patch antenna with triple meandered slots. Microstrip patch antenna with dual meander slot can achieve return loss until -24.54dB. However the gain of the antenna, 1.46 dBi is lower than microstrip patch antenna with triple meander slot which is 4.28 dBi. Other antenna parameters are also investigated such as bandwidth, radiation patterns and directivity have been observed and simulated. Measurement results are also recorded in this paper.

Dual-band monopole antenna for energy harvesting system

A planar dual-band monopole antenna is presented for Global System for Mobile Communications (GSM) band applications, which also have the potential to be used for energy harvesting system. The proposed antenna comprises of a ground plane at the back of the FR4 substrate and three microstrip lines which are physically connected with each other at the top surface of the substrate. The monopole antenna achieves good return loss at resonance frequencies of 915 MHz and 1800 MHz with a bandwidth value of 124.2 MHz and 196.9 MHz respectively. The antenna gains of 1.97 dB and 3.05 dB are achieved at resonance frequencies of 900 MHz and 1800 MHz. Experimental results show good agreement with simulated performance. The output from the receiving antenna is also observed in order to analyze the relationship of the power level and the distance between transmitting and receiving antenna. This study is an early investigation in designing the RF energy harvesting system to support green technology and sustainable development particularly for Wireless Sensor Network (WSN) applications.

Transformation of generalized chebyshev lowpass filter prototype to Suspended Stripline Structure highpass filter for wideband communication systems

This paper presents the transformation of generalized Chebyshev lowpass filter prototype to highpass filter using Suspended Stripline Structure (SSS) technology. The study involves circuit analysis to determine generalized Chebyshev responses with a transmission zero at finite frequency. The transformation of the highpass filter from the lowpass filter prototype provides a cutoff frequency of 3.1 GHz with a return loss better than -20 dB. The design is simulated on a Roger Duroid RO4350 with a dielectric constant, εr of 3.48 and a thickness of 0.168 mm. The simulation performance results show promising results that could be further examined during the experimental works. This class of generalized Chebyshev highpass filter with finite transmission zero would be useful in any RF/ microwave communication systems particularly in wideband applications where the reduction of overall physical volume and weight as well as cost very important, while maintaining its excellent performance.

A parametric study on dual-band meander line monopole antenna for RF energy harvesting

This paper studies the dual-band monopole antenna based on meander line structure for Global System for Mobile Communications (GSM) band applications, which is also has the potential to be used for RF energy harvesting. A meander line antenna with a conductor line is investigated during the design using the Computer Simulation Tool (CST) software. The antenna is fabricated on a double-sided FR-4 printed circuit board using an etching technique. The comparison between simulation and measurement results for the return loss and radiation patterns are observed and are in good agreement. A bandwidth of 97 MHz and return loss of -19.29 dB is obtained at the first frequency band, i,e. 915 MHz, while a bandwidth of 46.2 MHz with a return loss of -16.27 dB are obtained at the second frequency band, i.e. 1800 MHz. This study is an early investigation in designing the RF energy harvesting to support green technology and sustainable development particularly for Wireless Sensor Network (WSN) as well as Radio Frequency Identification (RFID) applications.

Design of rectangular stacked patch antenna with four L-shaped slots and CPW-fed for WiMAX application

In this work, a novel coplanar waveguide (CPW) fed rectangular patch antenna embedded with four L-shaped slots for WiMAX application was proposed. This antenna is designed by using an FR4 epoxy board with dielectric constant, εr = 4.4, tangent loss, tan δ = 0.019 and the thickness of substrate, h = 1.6mm. There are two methods applied in this antenna to improve the characteristic of the antenna. The first method is by adding four L-shaped slots on the patch of the antenna to improve the bandwidth of the antenna. In order to improve the bandwidth and gain of the antenna, rectangular stacked patch above the basic patch have been suggested. The simulation of the antenna was done by using Computer Simulation Technology (CST) simulation software. Then, the fabricated antenna had been done to compare with the simulation result. It shows that the addition of a stacked patch on the microstrip patch antenna effect to achieve higher gain performance with 2.687 dB compared with an antenna without stacking patch with only 1.685 dB.

Dual layer rectangular microstrip patch antenna with H-slot for 2.4 GHz range applications

In this work, a dual layer rectangular microstrip patch antenna with H-slot is proposed for improving the return loss and enhanced gain at 2.4 GHz and 2.45 GHz. The antenna is designed by using CST Microwave Studio is used to design the mathematically based on the rectangular microstrip patch antenna. Simulated and experimental results obtained for this antenna show that it exhibits good radiation behavior within the RFID frequency range. It is found that this antenna shows - 18.584 dB at 2.45 GHz and - 19.692 dB at the resonant frequency of 2.442 GHz. At desired along this frequency band, the gain 2.228 dB at 2.442 GHz and 2.756 dB at 2.45 GHz is achieved.

Design of generalized Chebyshev lowpass filter with Defected Stripline Structure (DSS)

This paper presents the design of generalized Chebyshev lowpass filter (LPF) and integrated with Defected Stripline Structure (DSS) using Suspended Stripline Structure (SSS). The study involves circuit analysis to determine generalized Chebyshev responses with a transmission zero at finite frequency in order to produce a reduced number of elements values of prototype circuit. The LPF provides a cut-off frequency at 6 GHz with a return loss better than -19 dB, while the DSS exhibits a notch at frequency of 3.2 GHz with a stopband response better than -40 dB. Thus, the integrated LPF and DSS will produce lowpass and band reject response simultaneously. The design is implemented on a Roger Duroid RO4350 with a thickness of 0.168 mm and dielectric constant, εr of 3.48. The simulation performance results show promising results that could be proved in the experiment works. This new class of integrated LPF and DSS would be useful in any RF/ microwave communication systems particularly in wideband applications where the reduction of overall physical volume, weight and cost is critical to maintaining its good performance.

Double C-shaped monopole antenna array for dual band WLAN application

In this paper, a printed two C-shaped monopole antenna array for dual-band WLAN application is presented. The proposed antenna array contains two C-shaped monopole with a shorting line for connecting the two arms of the antenna elements. The purpose of the shorting line is to neutralize the current between the two arms which in return can increase the isolation. A parametric study was also carried out to investigate various parameters that effect the antenna design. The proposed antenna has been designed and simulated by using CST Microwave Studio simulation software. The return loss and gain result of the fabricated antenna is 25.40 dB and 2.91 dB at 2.40 GHz and 16.20 dB and 2.82 dB at 5.20 GHz.

INVESTIGATION OF DUAL MEANDER SLOT TO MICROSTRIP PATCH ANTENNA

A dual microstrip meander slot antenna is presented for Wireless Local Area Network (WLAN) application. The proposed antenna comprises a rectangular microstrip patch element embedded with two meander slots. The parametric study is performed to investigate the characteristics of microstrip patch antenna with double meandered slots compared to one without any meander slot. Microstrip patch antenna with dual meander slot can achieve return loss until -24.54dB. However, the gain of dual meander slot antenna is lower than the rectangular antenna. Other antenna parameters are also has been investigated such as bandwidth, radiation pattern and and directivity throughout simulation and measurement process. The proposed antenna has been designed and simulated by using CST Studio Suite 2010.

Investigation of Compact Tree-Shaped Coplanar Waveguide (CPW) Antenna for RF Energy Harvesting

This paper studies a compact wideband tree-shaped coplanar antenna which has the potential to be used for RF energy harvesting. The antenna is fabricated on a double-sided FR-4 printed circuit board using an etching technique. The effect of semi-circle patch embedded to a triangular patch has been studied. The comparison between simulation and measurement results for the return loss and radiation patterns are observed and are in good agreement. The measured return loss is in line with the simulation response where both manage to achieve lower than-10dB. A bandwidth of 3.64 GHz and 3.94 GHz were obtained in simulation and measurement process respectively. This study is an early investigation in designing the antenna for RF energy harvesting system to support green technology and sustainable development particularly for Wireless Sensor Network (WSN).