This paper presents the design and development of a planar Aligned-Gap and Centered-Gap Rectangular Multiple Split Ring Resonator (SRR) for microwave sensors that operates at a resonance frequency around 5 GHz. The sensor consists of a microstrip transmission line loaded with two elements of rectangular SRR on both sides. The proposed metamaterial sensors were designed and fabricated on Rogers RT5880 substrate having dielectric constant of 2.2 and thickness of 0.787 mm. The final dimension of the proposed sensor was measured at 35 × 14 mm2. Measured results show good agreement with simulated ones as well as exhibiting high Q-factor for use in sensing application. A remarkably shift of resonance frequency is observed upon introduction of several sample with different dielectric value.

Convolution Neural Network (CNN) is one of the techniques under Artificial Neural Network (ANN) used to develop a Deep Learning Neural Network (DLNN) algorithm for detection of Proliferative Diabetic Retinopathy (PDR) on the fundus images. About 116 PDR and 150 Non-Proliferative Diabetic Retinopathy (NPDR) of fundus images retrieved from the publicly available MESSIDOR database applied in this research. This study consisted three objectives that included the execution of two pre-processing techniques on the data-set which were resizing and normalizing the fundus images, developed deep learning operational Artificial Intelligence (AI) network of feature extraction algorithm for detection of PDR on the fundus images and determined the output classification of the network encompassing the accuracy, sensitivity and specificity. There were five different parameters carried out along this research. Here, Parameter 5 showed the best performance among the five parameters based on the value of accuracy, sensitivity, and specificity that was 73.81%, 76%, and 69% respectively.

In general, a classical Split Ring Resonator (SRR) structure exhibits high Q-factor based on deeper and sharper transmission dips at resonance as well as produce high electric field density at the gaps. It is believed, by introducing more gaps, a strong and localized E-field will be obtained in the area between the split gaps. Based on these features, three types of rectangular multiple Split Ring Resonators (SRRs) were proposed to resonate in the frequency range of 3-7 GHz and simulated using Computer Simulation Technology (CST) Microwave Studio to determine the transmission characteristics and the resonance frequency. A Nicolson-Ross-Weir (NRW) technique is used to retrieve the effective parameters from the resultant S-parameter. It is shown that the resonance frequency of investigated structures falls in a frequency region in which the real part of permeability is negative. Later, the simulated results were investigated and the performances as well as the size of each unit cell itself were compared. Simulation for three different type of dielectric samples were also presented to demonstrate that the proposed structure may be well suited for bio-sensing.

In this paper, the interest of microwave signals for biological detection applications using metamaterial structure as a biosensor element has been demonstrated. Microwave sensing is highly challenging for biological detection as it presents the attractive advantages of being contactless, non-invasive at low power level and yet its label free. The resonant frequency of the sensor is measured as 4.96 GHz. The shift in resonant frequency is employed as the sensor output for deoxyribonucleic acid (DNA) detection. The resonance frequency is shifted to the left when single stranded deoxyribonucleic acid (ssDNA) is immobilized onto gold surface and further shifted when hybridization or the binding event between the molecule of ssDNA and cDNA occurred. The sensitivity of this biosensor is up to 10 MHz/Molar with the detection limit of Molar is conducted during this experiment.

This paper presents the design and development of planar Aligned-Gap Multiple Split Ring Resonator (SRR) for microwave sensor that operates at resonance frequency around 5 GHz. The sensor consists of a microstrip transmission line loaded with two elements of Aligned-Gap Multiple Split Ring Resonator (SRR) on both sides. The proposed sensor was designed and fabricated on Rogers RT5880 substrate having dielectric constant of 2.2 and thickness of 0.254 mm. The final dimension of the proposed sensor was measured at 30 × 15 mm2. Measured result show good agreement with simulated ones as well as exhibiting high Qfactor for use in sensing application. An obvious shift of resonance frequency is observed upon introduction of several samples with different dielectric value.