Browsing by Author "Rahman, Muhammad Asad"

Now showing 1 - 7 of 7

A Design of a Metamaterial Integrated Triple Band Antenna for Wireless Applications
(IEEE Kerala, India, 20-Oct-2019) Dhar, Nipa; Dutta, Proma; Rahman, Muhammad Asad; Mobashsher, Ahmed Toaha; Hossain, Md. Azad
This paper represents a metamaterial (MTM)
Bandwidth-Enhanced Metamaterial Integrated Antenna for Wireless Applications
(Department of Electrical and Electronics Engineering, IUB, 26-Sep-2019) Dhar, Nipa; Rahman, Muhammad Asad; Hossain, Md. Azad; Mobashsher, Ahmed Toaha
This paper represents a metamaterial (MTM) integrated bandwidth-enhanced antenna for modern wireless communication systems. The MTM ultra wide-band (UWB) antenna comprises of two unit cells on the top of the substrate, a circular disc monopole, and a partial ground plane. The unit cell consists of a split ring resonator. Without unit cells, the monopole antenna can operate in a wide band of impedance bandwidth of 7.5 GHz, corresponding to a percentage bandwidth of 120% (2.5-10 GHz). After the integration of MTMs, the proposed antenna can operate from 1.5-10 GHz range with a percentage bandwidth of 147.8%. So, MTMs integration can provide additional operation at 1.5-2.5 GHz, thus the bandwidth is broadened. As the dimensions of the unit cells are much smaller than the resonant frequency,
Design and Performance Studies of a MIMO Antenna With Circular Polarization Diversity for 5G Applications
(Department of Electrical and Electronics Engineering, IUB, 26-Sep-2019) Chakraborty, Swarup; Mobashsher, Ahmed Toaha; Nishiyama, Ichihiko Eisuke Toyoda; Rahman, Muhammad Asad; Hossain, Md. Azad
An innovative 2-element multiple input multiple output (MIMO) antenna with the circular polarization (CP) diversity is proposed in this paper with an intention to use in the sub−6 GHz spectrum (3.6–3.8 GHz) for 5G wireless applications. A microstrip line fed slot antenna is working as a single element for the MIMO arrangement. An elliptical shaped slot and the unequal feed lines mechanism are used to sense CP for every element. For CP diversity, mirror operation between the antenna elements is performed. A rectangular slot line in the ground plane is inserted to realize better isolation between the antenna elements. The MIMO antenna provides good isolation < −25 dB between the antenna elements in 5G operating frequency band of 3.6−3.8 GHz. Considering 5 dBic gain as well as axial ratio (AR) less than 0.5 dB, this antenna shows promising CP radiation pattern. Moreover, result of envelope correlation coefficient (ECC) (< 0.002) and channel capacity loss (CCL) less than 0.3 b/sec/Hz make it suitable for fifth generation wireless applications.
Design and Performance Studies of an Elliptical Slot Circular Polarization Antenna for C-Band Wireless Applications
(Faculty of Electrical and Computer Engineering, CUET, 7-Feb-2019) Chakraborty, Swarup; Hossain, Md. Azad; Rahman, Muhammad Asad
A novel and subtle design of a circularly polarized
Design of an ITO Based CNT Coated Transparent Nano Patch Antenna Assisted by Characteristic Mode Analysis
(Department of Electrical and Electronics Engineering, IUB, 26-Sep-2019) Chowdhury, Md. Sarwar Uddin; Rahman, Muhammad Asad; Hossain, Md. Azad; Mobashsher, Ahmed Toaha
An Indium-doped Tin Oxide (ITO) based optically transparent nano-antenna is presented in this paper. E-shaped patch is used to resonate at 0.76 THz. Despite of high fractional bandwidth, the radiation efficiency as well as gain of the ITO based antennas are low due to high resistivity and low conductivity of ITO thin films. To overcome this limitation, carbon nano tube (CNT) is used as cover over radiating patch of the proposed antenna. As a result, due to high conductivity of CNT, along with gain and efficiency, the fractional bandwidth of the proposed antenna is also increased. Characteristic mode analysis (CMA) is carried out to provide more insightful physical characteristics of the proposed antenna. It helps to understand the structural optimization and to determine the operating frequency. Moreover, a copper based non-transparent E-shaped patch antenna, resonated at 0.76 THz is also designed to compare with the proposed antenna. The proposed antenna has fractional bandwidth of 21% which is much better than conventional patch antenna and some previous transparent antennas. A peak gain of 4.9 dBi is obtained at 0.76 THz with good radiation performance. The designed antenna is suitable for satellite communication because of its broad bandwidth, reasonable radiation efficiency, sufficient gain, light weight and compactness.
Design of an Orthogonal Feed Circularly Polarized Microstrip Array Antenna Suitable for Large Scale Extensible Arrays
(IEEE, 13-May-2016) Rahman, Muhammad Asad; Nishiyama, Eisuke; Toyoda, Ichihiko; Hossain, Md. Azad; Hossain, Quazi Delwar
This paper presents a circularly polarized 1×2 array antenna for X-band applications. Both-sided MIC technology is effectively used to design this array antenna as the array antenna consists of both microstrip lines and slot lines to realize the feed network. Patch elements and microstrip lines are placed on the top surface of the substrate and slot lines on the reverse surface (ground plan) of the substrate. Each of the patches is excited by two orthogonal feed lines. One of the feed lines is ahead by an odd multiple of quarter wavelength than the other feed line. This strategy makes the each patch circularly polarized. The impedance bandwidth is about 630 MHz and the 3-dB axial ratio bandwidth is more than 1%. This array antenna is very suitable to make large scale extensible array antennas by using it as a unit array.
Linear Polarization Switchable Patch Array Antenna using Magic-T Bias Circuit and Orthogonal Feed
(Department of Computer Science and Engineering, CUET, 21-Nov-2013) Hossain, Md. Azad; Chowdhury, Piyas; Hossain, Quazi Delwar; Goopta, Rubell Sen; Rahman, Muhammad Asad
In this paper, a linear polarization switchable patch array antenna is proposed. The orthogonal feed circuit and magic-T circuit is introduced to realize the proposed array antenna. The advantage of the magic-T circuit is the excellent isolation between the RF signal and the switching bias signal. The microwave integration technology is effectively employed to realize proposed linear polarization switchable array antenna. The proposed array antenna consists of four patch elements and 16 PIN diodes. In order to realize the ±45º polarization switching, four switching diodes are integrated with each patch elements. Using the ON/OFF condition of the diodes, the polarization axis can be easily switched to ±45º. The array antenna is realized in very simple and compact structure as all the antenna elements, feeding circuit and bias circuit are arranged on both sides of a dielectric substrate. The ability of the proposed array antenna to switch the polarization axis at ±45º at 10 GHz (X band) is confirmed by the experimental investigation.