Shah Alam, Malaysia
Shah Alam, Malaysia

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Ali M.T.,Antenna Research Group ARG | Awang Z.,Antenna Research Group ARG | Awang A.H.,Antenna Research Group ARG
Progress In Electromagnetics Research B | Year: 2014

The fabrication of single square patch antenna for proposed Leucaena Leucocephala ("Petai Belalang") Wood Plastic Composite (WPC) substrate board (PB Substrate board) and FR4 substrate board is presented in this paper. The experiment objective is to measure the performance of an antenna fabricated on the FR4 and PB substrate (proposed substrate) by comparing the performance in terms of material's dielectric constant and electron mobility and antennas' loss tangent, return loss (S11), radiation pattern and practical antenna transmitting performance. The new substrate compositions of Leucaena Leucocephala stem and polypropylene (PP) are 30% and 70% consecutively. The result for 150μm (sample B) indicates stability on most dielectric constant ("r = 3:02), loss tangent (tan±=0:029) and electron mobility (5:31£103 cm2/Vs), with the consistency of antenna result, between simulation and measurement. All results obtained will be analyzed and displayed in the form of data and graphs.


Azlan A.A.,Antenna Research Group ARG | Ali M.T.,Antenna Research Group ARG | Awang M.Z.,Antenna Research Group ARG | Ramli N.,Antenna Research Group ARG
RFM 2013 - 2013 IEEE International RF and Microwave Conference, Proceedings | Year: 2013

The fabrication of single patch antenna for proposed Leucaena Leucocephala ('Petai Belalang') Wood Plastic Composite (WPC) substrate board and FR4 substrate board is presented in this paper. The experiment objective was to measure the performance of an antenna fabricated on the proposed board by comparing the performance in term of Dielectric Constant value, Tangent Loss value, Return Loss, Radiation Pattern and Gain with antenna fabricated onto FR4 material substrate board. The idea is to find the potential alternative board replacing conventional printed circuit board (PCB) using commercial FR4 material. The dielectric constant and tangent loss value for both proposed and FR4 substrate board were analyzed with Agilent 85070E Dielectric Probe Kit method. The Fabricated proposed boards were studied in the frequency range of 2.2 to 3.3 GHz since this board will be used in ISM band application that occupied 2.45 GHz frequency spectrum. The parameter composition of proposed board on this paper was focused only on one density composition that is 70% of polypropylene and 30% of leucaena leucocephala filler wood with particle size maintained at 150 μM and moisture content of the filler is less than 5%. The indoor Practical Antenna Measurement method was used to prove the proposed antenna can be used as transmitting antenna and all result obtained were form as data and graph analysis. © 2013 IEEE.


Ramli N.,Antenna Research Group ARG | Ali M.T.,Antenna Research Group ARG | Yusof A.L.,Antenna Research Group ARG | Muhamud-Kayat S.,Antenna Research Group ARG
Asia-Pacific Microwave Conference Proceedings, APMC | Year: 2013

This paper presents a novel design of frequency-reconfigurable antenna by using an aperture-coupled technique as feeding technique and stacked patch technology. The proposed antenna generally consists of three substrate layers (RT-Rogers 5880) and air gap filled between feedline substrate and layer 2 substrates. Four PIN diode (BAP51-02) switches are implemented to configure the length of the feedline by configuring the switches to ON or OFF mode. A new approach of coupling methods is presented. When all the switches are in ON mode, the signal will be passed to the selective aperture slot and activate the particular radiating patch layer to achieve the frequency reconfigurability either at 2.6 GHz or 3.5 GHz. The prototype of the proposed antenna is tested/fabricated with the biasing circuit to validate the performance of the antenna. The simulated and measured results are presented to confirm the performance of the antenna. © 2013 IEEE.


Ramli N.,Antenna Research Group ARG | Ali M.T.,Antenna Research Group ARG | Yusof A.L.,Antenna Research Group ARG | Islam M.T.,National University of Malaysia | Muhamud-Kayat S.,Antenna Research Group ARG
Progress In Electromagnetics Research C | Year: 2014

This paper presents a frequency and pattern reconfigurable stacked patch microstrip array antenna fed by aperture-coupled technique. The antenna consists of three substrate layers with radiating elements sorted at substrate layer 1 (top patches) and substrate layer 2 (bottom patches). The layers have different sizes to indicate different operating frequencies. On the ground plane, the four sets of two different aperture slot shapes (I-shaped and H-shaped) are used to transfer the wave and signal to particular radiating elements during the PIN diode switches configurations. The I-shaped slots are used to activate the bottom patches while the H-shaped slots are used to activate the top patches. Four PIN diode switches are placed at the feed line, positioned between the I- and H-shaped slots. Next, by changing the PIN diode switches configuration to ten cases, the proposed antenna has capabilities to change the operating frequencies and the pattern characteristics itself. The measured results of return loss, gain and radiation patterns are slightly shift compared to the simulated results.


Ramli N.,Antenna Research Group ARG | Ali M.T.,Antenna Research Group ARG | Tan M.N.M.,Antenna Research Group ARG | Yusof A.L.,Antenna Research Group ARG
2013 10th International Conference on Electrical Engineering/Electronics, Computer, Telecommunications and Information Technology, ECTI-CON 2013 | Year: 2013

This paper presents a novel of a Frequency Reconfigurable Stacked Patch Microstrip Antenna (FRSPMA) integrated with radio frequency (RF) switch. It consists of three substrate layers where all layers uses RT-Rogers 5880 with a thickness of h1=0.787 mm. A 0.3mm (h2) thick air gap is filled between the stacked radiating patch (layer 1 and layer 2) and the feedline substrate to enhance the gain performances, thus reducing the spurious effects from the feeding line. A new coupling method applied in an aperture coupled technique that controlled by the switching circuit is presented. In this design, two different shapes of aperture slots (I-shape and H-shape) were etched on the ground plane. The position of each aperture slot must be located at the centre with reference to the bottom and top patch position. A PIN diode switch was deployed at the feed network to control the length of feedline in order to achieve frequency reconfigurable. By configuring the PIN diode switch either to ON or OFF state, the particular aperture slots on the ground plane will be activated or turned ON, hence allowing waves to radiate to the selected radiating element at different substrate layers (top or bottom patch). The activation of the selected aperture slots and radiating elements ensures the FRSPMA is capable to operate either at 2.6 GHz or 3.5 GHz frequency. The proposed antenna was then fabricated into two structures, with and without the real PIN diode switch (copper stripline). The simulated results were then compared with the measured results to ensure that the antenna's performance in terms of frequency, return loss, gain and the characteristics of the radiation pattern are exceptional. After observation and analyzing made, both results demonstrated a good impedance matching. The findings and results from this research grants a potential benefit to the comprehension of wireless communication systems, especially for Long Term Evolution (LTE) and WiMAX applications. © 2013 IEEE.


Alias H.,Antenna Research Group ARG | Ali M.T.,Antenna Research Group ARG | Ramli S.S.N.,Antenna Research Group ARG | Sulaiman M.A.,Antenna Research Group ARG | Kayat S.,Antenna Research Group ARG
2013 10th International Conference on Electrical Engineering/Electronics, Computer, Telecommunications and Information Technology, ECTI-CON 2013 | Year: 2013

This paper presents a novel design of aperture coupled microstrip antenna with back lobe reduction. The proposed design was based on the structure of a 2 by 2 planar array antenna with separated feeding technique, aperture coupler. The antenna is designed on Rogers Duroid substrate having dielectric, ε, of 2.2. Four dumbbell shaped DGS were etched on the ground plane for back radiation reduction. An antenna without DGS is first designed acting as reference. Both of the designs were simulated in CST Microwave Studio 2011 software based on operating frequency of 5.8GHz. A parametric study was done to investigate the effect of DGS dimensions. The results show that, by incorporating DGS onto the antenna, back radiation is reduced. The back lobe level is reduced from 4.6dB to 0.4887dB. Return loss were also improved from -26.089dB to -41.28dB. This design concept can be useful in reducing the back radiation of aperture coupled microstrip antenna. © 2013 IEEE.


Kayat S.M.,Antenna Research Group ARG | Ali M.T.,Antenna Research Group ARG | Salleh M.K.M.,Antenna Research Group ARG | Rusli M.H.M.,University Technology of MARA | And 2 more authors.
RFM 2013 - 2013 IEEE International RF and Microwave Conference, Proceedings | Year: 2013

This paper presents a novel structure of frequency reconfigurable truncated rhombus-like slotted antenna (FRTRSA). The structure consists of a slotted ground plane with a thickness of ho sandwiched between two different substrates of different thicknesses, h1 and h2. The upper substrate has lower dielectric constant, erl than the bottom substrate, er2. Unlike a conventional antenna which provides only one frequency per antenna, the proposed antenna is focused to operate at two different frequencies in a single antenna by using corporate feed array configuration. A 'zig-zag' slot which is embedded at each radiating patch at two different orientations in x- and y-axis has significantly influenced the excitations of the resonant frequencies. Therefore, the uniqueness of the antenna is that it has the same patch size although two different frequencies are achieved. The antenna is integrated with the PIN diodes at its feed network to reconfigure the desired frequency. CST Microwave Studio has been used for design simulation and optimization. Simulated and measured results are presented and both results are in a good agreement. The results confirm that the antenna can be reconfigured at two frequency modes, F1=5.3GHz and F2=5.8GHz. The proposed antenna has given a great advantage on the lower frequency with patch size reduction of 37.09%. © 2013 IEEE.


Alias H.,Antenna Research Group ARG | Ali M.T.,Antenna Research Group ARG | Subahir S.,Antenna Research Group ARG | Ya'Acob N.,Antenna Research Group ARG | Sulaiman M.A.,Antenna Research Group ARG
IEEE Symposium on Wireless Technology and Applications, ISWTA | Year: 2013

This paper presents a novel design of aperture coupled microstrip antenna (ACMSA) integrated with DGS and parasitic elements. The basic design of the proposed antenna is 2 by 2 planar array with aperture coupler feeding technique. Four dumbbell-shaped DGS are etched on the ground plane, for back radiation reduction, which is sandwiched between the upper and lower substrates. Both of the substrates are Rogers Duroid 5880 of thickness 0.767mm with dielectric constant of 2.2. Twelve trapezoidal-shaped parasitic elements are placed onto the first substrate, three besides each patch, for gain enhancement. The antenna design is simulated in CST Microwave Studio 2011 software based on operating frequency of 5.8GHz. The results show that back lobe level is reduced from 4.6dB to 0.1331dB. With the parasitic element, the gain of the antenna which was dropped, from 11.8dB to 11.2dB when DGS is added, is improved to 11.5dB. Reflection coefficient for the antenna is -27.50dB. This design concept can be useful in reducing the back radiation of aperture coupled microstrip antenna. © 2013 IEEE.


Ramli N.,Antenna Research Group ARG | Ali M.T.,Antenna Research Group ARG | Yusof A.L.,Antenna Research Group ARG | Muhamud-Kayat S.,Antenna Research Group ARG | Alias H.,Antenna Research Group ARG
Progress In Electromagnetics Research C | Year: 2013

In this paper, a new Frequency-Reconfigurable Stacked Patch Microstrip Antenna (FRSPMA) with a new coupling method applied in an aperture-coupled technique controlled by the switching circuit is presented. This antenna uses a combination of aperture-coupled technique and stacked patch in order for the radiating elements to increase the bandwidth. Two shapes (I-shape and H-shape) and sizes of aperture slots are etched onto the ground with a purpose to couple the energy between feedline and stacked patch. One PIN diode switch is integrated in the feed network to control the length of the feedline. A variation of the feedline length controls the selected aperture slots to be active. The waves from the selected activated aperture slots will radiate to particular radiating patch (top or bottom patch) and achieve the frequency reconfigurability. When the switch is in ON mode, the antenna has a capability to configure its operating frequency at 2.6GHz and at 3.5 GHz during the OFF mode. Besides that, the air gap is used to improve and avoid any coupling problem between the aperture slots and both of the two patches. Improper alignment between the aperture slots and patches will interfere waves radiating from aperture slots to the particular patch. In addition, the proposed antenna produces a high gain of more than 5dB during ON or OFF modes, respectively. The simulated results are compared with measured results.

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