Md. Moinul Islam

A Miniaturized Antenna with Negative Index Metamaterial Based on Modified SRR and CLS Unit Cell for UWB Microwave Imaging Applications

A miniaturized antenna employing a negative index metamaterial with modified split-ring resonator (SRR) and capacitance-loaded strip (CLS) unit cells is presented for Ultra wideband (UWB) microwave imaging applications. Four left-handed (LH) metamaterial (MTM) unit cells are located along one axis of the antenna as the radiating element. Each left-handed metamaterial unit cell combines a modified split-ring resonator (SRR) with a capacitance-loaded strip (CLS) to obtain a design architecture that simultaneously exhibits both negative permittivity and negative permeability, which ensures a stable negative refractive index to improve the antenna performance for microwave imaging. The antenna structure, with dimension of 16 × 21 × 1.6 mm3, is printed on a low dielectric FR4 material with a slotted ground plane and a microstrip feed. The measured reflection coefficient demonstrates that this antenna attains 114.5% bandwidth covering the frequency band of 3.4–12.5 GHz for a voltage standing wave ratio of less than 2 with a maximum gain of 5.16 dBi at 10.15 GHz. There is a stable harmony between the simulated and measured results that indicate improved nearly omni-directional radiation characteristics within the operational frequency band. The stable surface current distribution, negative refractive index characteristic, considerable gain and radiation properties make this proposed negative index metamaterial antenna optimal for UWB microwave imaging applications.

A Negative Index Metamaterial-Inspired UWB Antenna with an Integration of Complementary SRR and CLS Unit Cells for Microwave Imaging Sensor Applications.

This paper presents a negative index metamaterial incorporated UWB antenna with an integration of complementary SRR (split-ring resonator) and CLS (capacitive loaded strip) unit cells for microwave imaging sensor applications. This metamaterial UWB antenna sensor consists of four unit cells along one axis, where each unit cell incorporates a complementary SRR and CLS pair. This integration enables a design layout that allows both a negative value of permittivity and a negative value of permeability simultaneous, resulting in a durable negative index to enhance the antenna sensor performance for microwave imaging sensor applications. The proposed MTM antenna sensor was designed and fabricated on an FR4 substrate having a thickness of 1.6 mm and a dielectric constant of 4.6. The electrical dimensions of this antenna sensor are 0.20 λ × 0.29 λ at a lower frequency of 3.1 GHz. This antenna sensor achieves a 131.5% bandwidth (VSWR < 2) covering the frequency bands from 3.1 GHz to more than 15 GHz with a maximum gain of 6.57 dBi. High fidelity factor and gain, smooth surface-current distribution and nearly omni-directional radiation patterns with low cross-polarization confirm that the proposed negative index UWB antenna is a promising entrant in the field of microwave imaging sensors.

Microwave Imaging Sensor Using Compact Metamaterial UWB Antenna with a High Correlation Factor

The design of a compact metamaterial ultra-wideband (UWB) antenna with a goal towards application in microwave imaging systems for detecting unwanted cells in human tissue, such as in cases of breast cancer, heart failure and brain stroke detection is proposed. This proposed UWB antenna is made of four metamaterial unit cells, where each cell is an integration of a modified split ring resonator (SRR), capacitive loaded strip (CLS) and wire, to attain a design layout that simultaneously exhibits both a negative magnetic permeability and a negative electrical permittivity. This design results in an astonishing negative refractive index that enables amplification of the radiated power of this reported antenna, and therefore, high antenna performance. A low-cost FR4 substrate material is used to design and print this reported antenna, and has the following characteristics: thickness of 1.6 mm, relative permeability of one, relative permittivity of 4.60 and loss tangent of 0.02. The overall antenna size is 19.36 mm × 27.72 mm × 1.6 mm where the electrical dimension is 0.20 λ × 0.28 λ × 0.016 λ at the 3.05 GHz lower frequency band. Voltage Standing Wave Ratio (VSWR) measurements have illustrated that this antenna exhibits an impedance bandwidth from 3.05 GHz to more than 15 GHz for VSWR < 2 with an average gain of 4.38 dBi throughout the operating frequency band. The simulations (both HFSS and computer simulation technology (CST)) and the measurements are in high agreement. A high correlation factor and the capability of detecting tumour simulants confirm that this reported UWB antenna can be used as an imaging sensor.

Design of a split P-shaped multiband microstrip patch antenna for modern communication system

A fictional design of a compact microstrip patch antenna for multiband frequency has been depicted in this paper. The proposed design presents a slit P-shaped antenna that operates at 3.5 GHz, 5.9 GHz, 9.2 GHz and 13.1 GHz. FR-4 (lossy) is used as substrate to design the recommended antenna which has a firm dimension of 18 × 20 mm2. This antenna operates at S, C, X and Ku band with moderate bandwidth because of its design and feedline. This P-shaped multiband antenna has directive gain of 3.3dBi, 4.9 dBi, 6.5 dBi and 7.1 dBi at resonating frequencies and is suitable for a modern communication system. Regarding this antenna, the results are obtained in terms of Return Loss, Voltage Standing Wave ratio, Gain and Radiation Pattern which have admissible values of return loss less than −10 dB, VSWR less than 2 at each resonant frequencies and Gain more than 3 dB.

Microstrip line-fed monopole antenna on an epoxy-resin-reinforced woven-glass material for super wideband applications

Abstract A microstrip line-fed monopole antenna is proposed for super wideband (SWB) applications printed on an epoxy-resin-reinforced woven-glass material. The reported SWB antenna has been made of a rectangular partial ground plane with an L-type slit and a heart-shaped radiating patch. This antenna is connected precisely by a tapered feed line that provides SWB greater than ultra-wideband. The heart-shaped radiating patch and the partial ground plane containing a gap and an L-type slit on ground plane also play paramount roles to procure wide impedance bandwidth. It is determined from measurements that this antenna contains SWB characteristic [voltage standing wave ratio (VSWR) ≤2] spanning from 1.30 to 40 GHz (187.41%), with a bandwidth dimension ratio (BDR) of 5544.66 and a ratio bandwidth of 30.77:1. Simple construction, sharp surface current flow, much impedance bandwidth, nearly omnidirectional radiation patterns, stable peak gain (2.20–6.06 dBi), time domain performance, and considerable BDR (5544.66) make it a promising candidate for SWB applications.

Design of a compact UWB antenna with a partial ground plane on epoxy woven glass material

Abstract A compact ultra-wideband (UWB) antenna is presented in this paper with a partial ground plane on epoxy woven glass material. The study is discussed to comprehend the effects of various design parameters with explicit parametric analyses. The overall antenna dimension is 0.22×0.26×0.016 λ. A prototype is made on epoxide woven glass fabric dielectric material of 1.6 mm thickness. The measured results point out that the reported antenna belongs to a wide bandwidth comprehending from 3 GHz to more than 11 GHz with VSWR<2. It has a peak gain of 5.52 dBi, where 3.98 dBi is the average gain. Nearly omnidirectional radiation patterns are observed within the operating frequency bands. A good term exists between simulation and measurement results, which lead the reported antenna to be an appropriate candidate for UWB applications.

A Parametric Study of Compact UWB Antenna with Multiple Notched-Band Functions

In the paper, a parametric study of compact UWB antenna is conducted with multiple notched-band functions. Three notch bands at 3.6, 7.5, and 8.3 GHz frequencies have been attained with three slots on the radiating patch whereas two notch bands at 5.2 and 5.8 GHz frequencies have been acquired with two slots on the partial ground plane. This proposed antenna covers impedance bandwidth (VSWR ˂ 2) from 3.06 to 10.67 GHz with notch band 3.4–3.8 GHz (WiMAX), 5.1–5.35 GHz (WLAN), 5.6–6 GHz (WLAN), 7.15–7.65 GHz (X-band satellite communication) and 8.05–8.65 GHz (ITU 8-GHz band) whereas the overall antenna size is 25 mm × 31 mm. The parametric studies are executed depending on the surface current flow and design parameters of slots.