Terahertz Microstrip Patch Antenna for Breast Tumour Detection

Breast cancer is one of the most common cancers among Malaysian women. It is critical to discover strategies to detect the tumour early on. Terahertz (THz) frequency provides excellent qualities for detecting tumours such as low photon energy and non-ionising radiation as compared to prior methods such as mammography, ultrasound, and magnetic resonance imaging (MRI) that use optical to X-ray frequencies. The purpose of this work is to analyse and locate a breast tumour as well as to compute the maximum specific absorption rate (SAR) value. It was designed a THz rectangular microstrip patch antenna with an inset feed. To improve the antenna's performance, graphene was used for the patch and polyimide for the substrate. This antenna covered a bandwidth of 31.6 GHz and worked in the frequency range of 0.283-0.599 THz. To identify the location of a tumour, compute the SAR value, and localise the tumour, SAR simulation was used. The maximum SAR shifted to the tumor's position due to greater absorption rate around its tissue due to higher dielectric constant features. It was calculated that 1e-05g of average mass is required to be less than total tissue mass, which is 2.0063e-05g. SAR study revealed a maximum SAR value of 2.49391e+06 W/kg, which was not more than the overall absorption rate for human body safety. The SAR calculation result revealed that the tumour is within the range of the tumor's initial location

BANDWIDTH ENHANCEMENT ON MICROSTRIP RECTANGULAR PATCH ANTENNA WITH ELECTROMAGNETIC BAND GAP STRUCTURE FOR WI-FI APPLICATION

Use of microstrip patch antenna is very popular, but microstrip patch antenna suffer from a number of disadvantages such as narrow bandwidth. In this paper, a planar Electromagnetic Band-Gap (EBG) structures are used for further enhances the antenna bandwidth. An inset rectangular patch antenna was designed to work with a design frequency of 2.4 GHz. To analyze the EBG properties, the suspended transmission line method is used. In order to bandwidth enhancement, 1x3 EBG array arrange on the same layer of antenna’s patch but the distance between patch and EBG were optimized. Simulation and measurement result are compared. In the end, it resulted the bandwidth of the rectangular microstrip antenna has increased 1.79 % noticeably by using the EBG structures for simulation result and increased 4.8 % for measurement result, and inclusion of EBG structure also improve gain as much as 0.345 dB and increase directivity of antenna 0,309 dBi. Application of EBG structure succeeds to increase the performance of antenna in simulation and measurement result respectively.Index term- microstrip patch antenna, planar Electromagnetic Band-Gap (EBG)

Bandwidth Enhancement on Microstrip Rectangular Patch Antenna with Electromagnetic Band Gap Structure for Wi-fi Application

Use of microstrip patch antenna is very popular, but microstrip patch antenna suffer from a number of disadvantages such as narrow bandwidth. In this paper, a planar Electromagnetic Band-Gap (EBG) structures are used for further enhances the antenna bandwidth. An inset rectangular patch antenna was designed to work with a design frequency of 2.4 GHz. To analyze the EBG properties, the suspended transmission line method is used. In order to bandwidth enhancement, 1x3 EBG array arrange on the same layer of antenna's patch but the distance between patch and EBG were optimized. Simulation and measurement result are compared. In the end, it resulted the bandwidth of the rectangular microstrip antenna has increased 1.79 % noticeably by using the EBG structures for simulation result and increased 4.8 % for measurement result, and inclusion of EBG structure also improve gain as much as 0.345 dB and increase directivity of antenna 0,309 dBi. Application of EBG structure succeeds to increase the performance of antenna in simulation and measurement result respectively.Index term- microstrip patch antenna, planar Electromagnetic Band-Gap (EBG)

Beam Steering using the Active Element Pattern of Antenna Array

An antenna array is a set of a combination of two or more antennas in order to achieve improved performance over a single antenna. This paper investigates the beam steering technique using the active element pattern of dipole antenna array. The radiation pattern of the array can be obtain by using the active element pattern method multiplies with the array factor. The active element pattern is crucial as the mutual coupling effect is considered, and it will lead to an accurate radiation pattern, especially in determining direction of arrival (DoA) of a signal. A conventional method such as the pattern multiplication method ignores the coupling effect which is essential especially for closely spaced antenna arrays. The comparison between both techniques has been performed for better performance. It is observed that the active element pattern influenced the radiation pattern of antenna arrays, especially at the side lobe level. Then, the beam of the 3x3 dipole antenna array has been steered to an angle of 60° using three techniques; Uniform, Chebyshev and Binomial distribution. All of these are accomplished using CST and Matlab software

Analysis, Optimization, and Hardware Implementation of Dipole Antenna Array for Wireless Applications

The antenna pattern synthesis is one of the signifiant problems in the phased array antenna. Pattern synthesis refers to the optimized weight excitation of each antenna element in order to steer the beam electronically without mechanically rotating the antenna. It can be achieved by using a combination of phase shifters and attenuator circuits. In this paper, a 2 by 2 dipole antennas with an RF beamforming circuit has been designed to steer the main beam along the The azimuth plane main beam coverage from 100° to 140° with a step size of 10° has been successfully optimized using a hybrid of the induced EMF method and a genetic algorithm. The optimization results were compared to the full-wave simulation technique implemented in Empire XCCel. The design is realistically implemented at 2.45GHz, with both simulation and measurement results shown. The measured reflection coefficient of the phased array antenna is −48dB at 2.56GHz. The feasibility of the beam synthesis has been validated successfully with the main beam being steered at 110°. The possibility of a fabrication discrepancy resulting in minor radiation degradation is also discussed in this research. The dipole antenna system with RF beamformer circuit can be applied to indoor positioning systems such as Wi-Fi, wireless local area network (WLAN), and fifth-generation

Beam steering using the active element pattern of antenna array

An antenna array is a set of a combination of two or more antennas in order to achieve improved performance over a single antenna. This paper investigates the beam steering technique using the active element pattern of dipole antenna array. The radiation pattern of the array can be obtain by using the active element pattern method multiplies with the array factor. The active element pattern is crucial as the mutual coupling effect is considered, and it will lead to an accurate radiation pattern, especially in determining direction of arrival (DoA) of a signal. A conventional method such as the pattern multiplication method ignores the coupling effect which is essential especially for closely spaced antenna arrays. The comparison between both techniques has been performed for better performance. It is observed that the active element pattern influenced the radiation pattern of antenna arrays, especially at the side lobe level. Then, the beam of the 3x3 dipole antenna array has been steered to an angle of 60° using three techniques; Uniform, Chebyshev and Binomial distribution. All of these are accomplished using CST and Matlab softwar

Design and optimize microstrip patch antenna array using the active element pattern technique

Microstrip patch antennas are widely used in modern day communication devices due to their light weight, low cost and ease of fabrication. In this paper, we have designed and fabricated two Microstrip Patch Antennas (slotted-ring and truncated-slotted ring) and array at 2.4 GHz for Wireless Local Area Network (WLAN) applications using Computer Simulation Technology, CST. The antenna design consists of rectangular radiating patch on Rogers RT5880 substrate and is excited by using coaxial probe feeding technique. The truncated-slotted ring has been designed on top of the radiating patch to improve bandwidth. The simulation and measurement results of the both antennas are in close agreement with each other. Due to the good agreement of simulation and measurement results of truncatedslotted ring antenna in comparison with slotted-ring antenna, it has been selected for antenna array design. The simulated and measured S11 of truncated-slotted ring antenna shows -21dB and -15.6 dB at 2.4 GHz respectively. Then, the antenna has been formed into 1x4 array in order to observe its beamforming capability. The proposed antenna array is suitable for 802.11b/g/n Wi-Fi standard which is proposed to be used for IoT

Novel Spiral With and Without Patch EBG Structures for EMI Reduction

Electromagnetic bandgap structures (EBGs) have the ability to provide excellent reduction of electromagnetic interference (EMI). In this work, a 3 by 3 spiral with and without patch electromagnetic bandgap planar was fabricated on low cost FR4 substrate with permittivity of 4.3 and thickness of 1.6mm. Both designs have dimensions of 36 mm x 36 mm covering 9 unit cells planar design. The simulation and experimental characteristics are illustrated in this paper. An acceptable agreement between the simulated and measured results was obtained. It was found that the spiral without patch EBG experienced better bandgap than the spiral with patch design, which covered bandgap of (5.8 – 7.4 GHz) with relative bandwidth of 22.56%. Meanwhile, for the spiral with patch structure, it covered C band (4.5 – 7 GHz) with extended relative bandwidth of 43%. The results of the characteristics demonstrate that the proposed EBGs are attractive candidates for the integration into the high speed circuitry designs where spiral with patch can be involved in C band applications to suppress the EMI emitted by their circuitry

Electrical characterization of material thickness based on free space method using patch antennas

This paper investigates electrical characterization (such as permittivity and permeability) of materials using the free space method. The technique employs a simulation design using full wave software CST consisted of two slotted patch antennas at 2.4 GHz and a slab of FR4 that has been placed in between of the antennas. The S parameters (S 11 and S 21 ) were extracted from simulation and the electrical characteristics of FR4 were calculated using Nicolson-Ross-Weir (NRW) and Smith methods. It comes to the knowledge that the NRW technique has limitation in terms of material thickness which affects the value of permittivity and permeability of materials. Thus, a comparison has been made between these two methods by varying the material thickness of FR4 versus its permittivity and permeability. The thickness was varied from 5mm to 60mm. It was observed that these two techniques produce similar values of permittivity and permeability when the thickness has been varied up to 50 mm but differs when it was greater than 50 mm. On top of that, this paper also investigates the slotted patch antenna as a potential of RF sensor to investigate the unknown materials at 2.4 GHz

Compact Digital Television (DTV) Antenna for Indoor Usage

A compact indoor digital antenna for digital terrestrial television is proposed. The design of the antenna begins with the material selection to construct the antenna by using CST software with a standard monopole antenna design. The antenna is then simulated and optimized. A bandwidth of 290 MHz (46.14%) between 500 MHz and 790 MHz is achieved with the antenna gain more than 3 dBi. Simulated results is used to demonstrate the performance of the antenna. The simulated return losses, together with the radiation patterns and gain are presented and discussed