29 research outputs found
H-shaped terahertz patch antenna with metamaterials for biomedical applications
Get PDFThis paper presents the design and simulation of an H-shaped terahertz microstrip patch antenna integrated with a metamaterial (MTM) layer to enhance performance for biomedical sensing applications. The antenna modeled using high frequency structure simulator (HFSS), is optimized for 4.37 THz operation. While FR4 is used in simulations for baseline analysis, alternative low-loss substrates such as polyimide or quartz are recommended for practical THz applications. The antenna design uses an FR4 substrate with a dielectric constant of 4.4 and a thickness of 2 μm. Ground plane, feed line, and patch are made of copper material. The integration of the MTM enhance clearly the antenna characteristics. This integration helps to improve the antenna impedance matching; the reflection coefficients was enhanced from -25.01 to -63.10 dB. Additionally, this integration boost also the antenna radiation characteristics, increasing the gain from 2.62 to 3.86 dB and the directivity from 3.57 to 4.97 dB
SPATIAL MODELING OF THE TRANSMISSION CHANNEL FOR THZ RADIO COMMUNICATION SYSTEM
No full textDue to the growing demand for high speed wireless communication systems, it is crucial to look for new technology that can support this need. Indeed, THz technology has the potential to provide high data rate and multimedia applications for wireless communication system. In this paper, we evaluate the channel impulse response and the channel transfer function of terahertz system. The objective of this work is to propose an appropriate channel model for the THz bands. For this reason, we build a static model based on the existing Saleh-Valenzuela model. we have modified this classical model to adapt it to the THz context. The proposed model takes into account propagation losses and multipath propagation to provide designers with the impulse and frequency response of the channel, as well as their variations over time for mobile channels. Simulation results have shown that the distance between transmitter and receiver play a major role. Besides, multi-path effect introduces notches in the channel and create bands in which the channel become more selective. Moreover, the increase in the carrier frequency lied to a high path loss. These issues produce inter symbols interference which affect the performance of overall system. Therefore, to simulate an entire system including transmitters and receivers we should take into account this bands in order to get good reliability
Study and design of a patch antenna for biomedical applications
No full textThis work presents the performance of a Dual-band patch antenna with L-shaped slot for biomedical applications. The antenna works at 2.4 GHz and 3.33 GHz. A semi-flexible substrate material which is “Taconic TLX (tm)” with a relative dielectric constant, ℇr of 2.55, loss tangent, tan δ of 0.0019 and thickness, h of 0.7 mm has been proposed to be the isolant element of the antenna. The size of the antenna is 60 x 55 mm². The slots in the rectangular radiating patch were introduced to produce the resonant frequencies of 2.4GHz and 3.33GHz. The simulations of the microstrip patch antenna shows the reflection coefficient, S11 of -31.67 dB and -20.25 dB at 2.4 GHz and 3.27 GHz respectively. The proposed antenna shows a peak gain of 5.01 dB at 2.4 GHz. The results were obtained using HFSS (high frequency structured simulator) software
A comparative simulation study of different decoding schemes in LDPC coded OFDM systems for NB-PLC channel
Get PDFIn this paper, we study the performance of Low density Parity Check (LDPC) coded orthogonal frequency-division multiplexing (COFDM) systems when they are applied on the short data block of a narrowband (NB) power line communications (PLC) channel. In the modelled system simulations have been performed using different code lengths. It is assumed that the channel has a multipath propagation with two different noise scenarios: AWGN background noise with and without the presence of impulsive noise. Performances of Various soft and hard decision LDPC decoder schemes such as belief propagation (BP), weighted bit flipping (WBF), improved weighted bit flipping (IWBF) and implementation-efficient reliability ratio based weighted bit flipping (IRRWBF) decoders were investigated. It has been shown for all simulations performed in PLC channel model showed that remarkable performance improvement can be achieved by using short-length LDPC codes. Especially, the improvements are striking when the BP decoding algorithms are employed on the receiver side
Experimental Method of Ultrasonic Sensor for Ions and Solutions Discrimination and Identification
No full textPerformance enhancement of a terahertz patch antenna with metamaterials for 6G and biomedical applications
Get PDFThis paper introduces a novel approach for enhancing the performance of a terahertz (THz) patch antenna through the integration of metamaterials (MTM). The proposed design features a rectangular slotted patch antenna with a partial ground structure (DGS) that operates at 3.56 THz. The radiating element is situated on a substrate composed of silicon dioxide (SiO2) with a dielectric of 4 and a thickness of 2 µm. The proposed MTM is a 6×5 elements with a FR4 substrate characterized by a dielectric of 4.2 and a thickness of 2 µm. The MTM is integrated beneath the antenna as a strategic technique to enhance its performance. The results confirm the significant impact of this integration. The MTM improves impedance matching and makes the antenna more directional. Consequently, the reflection coefficient is improved from -18.06 dB to -52.50 dB, the gain is increased from 1.72 dB to 3.49 dB, and the directivity also is enhanced from 3.69 dB to 5.10 dB. All results were obtained using HFSS software
Analyzing the Influence of a Superstrate and Slot on a Circular Patch Antenna Operating at 2.4 GHz Resonance Frequency
No full textThe study of antenna design involved the application of a transmission line and cavity model at a 2.4 GHz frequency. The primary focus of this investigation was the impact of dielectric superstrates and a single slot on various performance metrics, encompassing aspects such as bandwidth, beamwidth, gain, resonance frequency, input impedance, return loss, and VSWR. This ongoing research builds upon the findings presented in different Article. The assessment considered factors like return loss and bandwidth to drive improvements and optimizations. Furthermore, a comprehensive examination of each antenna parameter was conducted using a parametric approach. Additionally, the study explored how the introduction of a slot affected the characteristics of circular patch antennas fed via coaxial probes, facilitating a comparative analysis based on their properties
Improving the performance of a U-shaped patch antenna using metamaterials for biomedical applications
Full text linkThis paper discusses the performance improvement of a patch antenna using metamaterials (MTM). The suggested antenna is a U-shaped patch antenna with a modified ground plane dedicated to biomedical applications. The size of the antenna is 40×20 mm2 with a FR4 substrate (εr=4.3, tanδ=0.02, H=1.6 mm) designed for operation at 2.4 GHz (ISM Band) and 6.23 GHz frequencies. The proposed MTM is 2×2 array positioned under the antenna at a distance of 2 mm. The integration of the MTM enhances clearly the antenna performance especially the return loss, voltage standing wave ratio (VSWR) and the gain. However, the reflection coefficient was enhanced from -10.71 dB to -36.63 dB at 2.45 GHz and from -13.88 dB to -36.54 dB at 6.23 GHz, the VSWR improved from 1.66 to 1.03 at 2.45 GHz and from 1.75 to 1.04 at 6.23 GHz. Additionally, the peak gain also was increased from 1.77 dB to 3.48 dB. The obtained results confirm the suitability of the suggested antenna for biomedical applications
