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Enhanced symmetrical split ring resonator for metallic surface crack detection Rammah A. Alahnomi; Z. Zakaria; Zulkalnain Mohd Yussof; Tole Sutikno; Ammar Alhegazi; Ahmed Ismail Abu-Khadrah
TELKOMNIKA (Telecommunication Computing Electronics and Control) Vol 17, No 4: August 2019
Publisher : Universitas Ahmad Dahlan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12928/telkomnika.v17i4.12939

An enhanced sensor based on symmetrical split ring resonator (SSRR) functioning at microwave frequencies has been proposed in order to detect and characterize the metal crack of the materials. This sensor is based on perturbation theory, in which the dielectric properties of the material affect the quality factor and resonance frequency of the microwave resonator. Conventionally, coaxial cavity, waveguide, dielectric resonator techniques have been used for characterizing materials. However, these techniques are often large, and expensive to build, which restricts their use in many important applications. Thus, the enhanced bio-sensing technique presents advantages such as high measurement sensitivity with the capability of suppressing undesired harmonic spurious and permits potentially metal crack material detection. Hence, using a High Frequency Structure Simulator (HFSS) software, the enhanced sensor is modeled and the reflection S11 is performed for testing the aluminum metal with crack and without crack at the frequency range of 100 MHz to 3GHz. Variation of crack width and depth has been investigated and the most obvious finding emerged from this study is that the ability of detecting a minimum of sub-millimeter crack width and depth which is a round 10 ????m width or depth where the minimum shift of reflected frequency is recorded at 6.2 MHz and 3 MHz for crack width and depth respectively. The enhanced SSRR provides high capability of detecting small crack defection by utilizing the interaction between coupled gap resonators and it is useful for various applications such as aircraft fuselages, nuclear power plant steam generator tubing, and steel bridges and for others that can be compromised by metal fatigue.

Analysis and investigation of a novel microwave sensor with high Q-factor for liquid characterization Ammar Alhegazi; Zahriladha Zakaria; Noor Azwan Shairi; Tole Sutikno; Rammah A. Alahnomi; Ahmed Ismail Abu-Khadrah
TELKOMNIKA (Telecommunication Computing Electronics and Control) Vol 17, No 2: April 2019
Publisher : Universitas Ahmad Dahlan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12928/telkomnika.v17i2.11901

In this paper, a new design of microwave sensor with high Q-factor for liquid characterization is analyzed and investigated. The new microwave sensor is based on a gap waveguide cavity resonator (GWCR). The GWCR consists of upper plate, lower plate and array of pins on the lower plate. The liquid under test (LUT) is characterized by placing it inside the GWCR where the electric field concentrates using a quartz capillary that is passing through microfluidic channels. The results show that the proposed sensor has a high Q-factor of 4832. Moreover, the proposed sensor has the ability to characterize different types of liquids such as oils, ethanol, methanol and distilled water. The polynomial fitting method is used to extract the equation of the unknown permittivity of the LUT. The results show that the evaluated permittivity using the proposed sensor has a good agreement with the reference permittivity. Therefore, the proposed sensor is a good candidate for food and pharmaceutical applications.

Enhanced Antenna Design for Rectenna Application in the 2.45 GHz ISM Band Sharif Ahmed; Zahriladha Zakaria; Mohd Nor Husain; Azahari Salleh; Ammar Alhegazi
TELKOMNIKA (Telecommunication Computing Electronics and Control) Vol 14, No 4: December 2016
Publisher : Universitas Ahmad Dahlan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12928/telkomnika.v14i4.4137

In this paper a two layers microstrip antenna design at 2.45 GHz ISM band with Harmonic rejection filter embedded on the ground plane is presented. The two roger substrates with relative permittivity of 2.2 are separated by an air gap which enhances the antenna gain. The design is simulated using Computer Simulation Technology (CST) Studio Suite 2015. Different aperture couplings slots such as rectangular and triangular aperture coupling slots are studied and compared. It is found that the antenna with triangular aperture coupling slot enhances the antenna performance by suppressing 2nd and 3rd harmonics at 5 GHz and 8 GHz, respectively, increasing the antenna gain and providing a better circular polarization behavior. The simulated antenna design achieves a gain of 9 dB, return loss of -23.6dB, axial ratio of 1.27dB and axial-ratio bandwidth of 40.8% (2 ~ 3 GHz). The proposed antenna shows an enhancement in the antenna performance which makes it a suitable candidate for rectifying antenna or rectenna application as it can increase the total conversion efficiency resulting in a high output DC voltage used to power low power electronic and electrical devices such as wireless sensor.

Determination of solid material permittivity using T-ring resonator for food industry Rammah A. Alahnomi; Z. Zakaria; Zulkalnain Mohd Yussof; Tole Sutikno; Amyrul Azuan Mohd Bahar; Ammar Alhegazi
TELKOMNIKA (Telecommunication Computing Electronics and Control) Vol 17, No 1: February 2019
Publisher : Universitas Ahmad Dahlan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12928/telkomnika.v17i1.11636

In this paper, we present a simple design of a T-ring resonator sensor for characterizing solid detection. The sensor is based on a planar microwave ring resonator and operating at 4.2 GHz frequency with a high-quality factor and sensitivity. An optimization of the T-ring geometry and materials were made to achieve high sensitivity for microwave material characterizations. This technique can determine the properties of solid materials from range of 2 GHz to 12 GHz frequencies. Techniques of current microwave resonator are usually measuring the properties of material at frequencies with a wide range; however, their accuracy is limited. Contrary to techniques that have a narrowband which is normally measuring the properties of materials to a high-accuracy with limitation to only a single frequency. This sensor has a capability of measuring the properties of materials at frequencies of wide range to a high-accuracy. A good agreement is achieved between the simulated results of the tested materials and the values of the manufacturer’s Data sheets. An empirical equation has been developed accordingly for the simulated results of the tested materials. Various standard materials have been tested for validation and verification of the sensor sensitivity. The proposed concept enables the detection and characterization of materials and it has miniaturized the size with low cost, reusable, reliable, and ease of design fabrication with using a small size of tested sample. It is inspiring a broader of interest in developing microwave planar sensors and improving their applications in food industry, quality control and biomedical materials.

Wideband power amplifier based on Wilkinson power divider for s-band satellite communications Mussa Mabrok; Zahriladha Zakaria; Tole Sutikno; Ammar Alhegazi
Bulletin of Electrical Engineering and Informatics Vol 8, No 4: December 2019
Publisher : Institute of Advanced Engineering and Science

This paper presents design and simulation of wideband power amplifier based on multi-section Wilkinson power divider. Class-A topology and ATF-511P8 transistor have been used. Advanced Design System (ADS) software used to simulate the designed power amplifier. The simulation results show an input return loss (S11)<-10dB, gain (S21)>10 dB over the entire bandwidth, and an output power around 28dBm at the Centre frequency of 3GHz. The designed amplifier is stable over the entire bandwidth (K>1). Inter-modulation distortion is -65.187dBc which is less than -50dBc. The designed amplifier can be used for the microwave applications which include weather radar, satellite communication, wireless networking, mobile, and TV.

Wideband power amplifier based on Wilkinson power divider for s-band satellite communications Mussa Mabrok; Zahriladha Zakaria; Tole Sutikno; Ammar Alhegazi
Bulletin of Electrical Engineering and Informatics Vol 8, No 4: December 2019
Publisher : Institute of Advanced Engineering and Science

This paper presents design and simulation of wideband power amplifier based on multi-section Wilkinson power divider. Class-A topology and ATF-511P8 transistor have been used. Advanced Design System (ADS) software used to simulate the designed power amplifier. The simulation results show an input return loss (S11)<-10dB, gain (S21)>10 dB over the entire bandwidth, and an output power around 28dBm at the Centre frequency of 3GHz. The designed amplifier is stable over the entire bandwidth (K>1). Inter-modulation distortion is -65.187dBc which is less than -50dBc. The designed amplifier can be used for the microwave applications which include weather radar, satellite communication, wireless networking, mobile, and TV.

UWB Filtenna with Electronically Reconfigurable Band Notch using Defected Microstrip Structure Ammar Alhegazi; Zahriladha Zakaria; Noor Azwan Shairi; Tole Sutikno; Sharif Ahmed
Indonesian Journal of Electrical Engineering and Computer Science Vol 8, No 2: November 2017
Publisher : Institute of Advanced Engineering and Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.11591/ijeecs.v8.i2.pp302-307

A new design of filtenna with electronically reconfigurable band notch for ultra-wideband (UWB) applications is presented. The filtenna is designed based on modified monopole antenna integrated with resonant structure. To produce wider bandwidth with better return loss and higher frequency skirt selectivity, the monopole antenna is modified using microstrip transition in the feedline and block with a triangular-shape slot on each side of the circular patch. The resonant structure is about U-shaped slot defected on the feedline to achieve band notch characteristic. The position of the created band notch is controlled by optimizing the length of the U-shaped slot. By using a PIN diode switch inserted in the U-shaped slot to achieve reconfigurability feature. The experimental results show that the proposed design exhibits a wide bandwidth ranging from 3.0 to 14.0 GHz with reconfigurable band notch at 5.5 GHz (WLAN), and omnidirectional radiation pattern. Therefore, the proposed design is a good candidate for modern UWB applications.

Analysis and Investigation of a Novel Microwave Sensor with High Q-Factor for Oil Sensing Ammar Alhegazi; Zahriladha Zakaria; Noor Azwan Shairi; Tole Sutikno; Rammah A. Alahnomi; Ahmed Ismail Abu-Khadrah
Indonesian Journal of Electrical Engineering and Computer Science Vol 12, No 3: December 2018
Publisher : Institute of Advanced Engineering and Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.11591/ijeecs.v12.i3.pp1407-1412

In this paper, a novel microwave sensor with high Q-factor for oil sensing is analyzed and investigated. The new design is based on a gap waveguide cavity resonator (GWCR). To characterize and evaluate the sample, the oil under tested (OUT) is injected into a Teflon tube, which is passing through the microfluidic channel that is located in the middle of the cavity where the electric field concentrates. The results show that the proposed sensor has a high Q-factor of 4832. Moreover, the proposed design has the ability to sense and detect different types of oils with a small variation of permittivities such as Fish oil, Coconut oil, Olive oil, Linseed oil and Castor oil. The permittivity equation is extracted using the polynomial fitting method to define unknown dielectric properties of the OUT. The results show that the evaluated permittivity using the proposed sensor has a good agreement with the ideal permittivity. Therefore, the proposed sensor is a good candidate for oil processing in food industries.

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