Agriculture Credit and Economic Growth in Bangladesh: A Time Series Analysis

The paper examined the impact of agricultural credit on economic growth in Bangladesh. The annual data of agriculture credit were collected from annual reports of the Bangladesh Bank and other data were collected from the world development indicator (WDI) of the World Bank. By employing Johansen cointegration test and vector error correction model (VECM), the study revealed that there exists a long run relationship between the variables. The results of the study showed that agriculture credit had a positive impact on GDP growth in Bangladesh. The study also found that gross capital formation had a positive, while inflation had a negative association with economic growth in Bangladesh. Therefore, the government and policymakers should continue their effort to increase the volume of agriculture credit to achieve sustainable economic growth

Investigation of highly birefringent and highly nonlinear Hexa Sectored PCF with low confinement loss

A novel design of Hexa Sectored Photonic Crystal Fiber (HS-PCF) with high nonlinearity and high birefringence has been revealed in this paper where core is slotted and filled with Gallium Phosphide (GaP). Finite Element Method has been used for numerical investigation of the proposed PCF along with finer mesh. Different optical parameters like nonlinearity, effective area, power fraction, birefringence, confinement loss and Numerical Aperture (NA) have been explored by proper tuning of Geometrical variables. The investigation shows that, proposed PCF exhibits high nonlinearity of 9.47 × 104 W−1Km−1 at the operating wavelength of 1.4 µm along with high birefringence of 0.259, Numerical aperture of 0.8774 and very low confinement loss of 5.78 × 10−9 dB/m at the optical wavelength of 2.0 µm. Therefore, it is expected that this proposed PCF could be a strong candidate in biomedical imaging, super continuum generation and sensing applications considering polarized light. Keywords: Photonic crystal fiber, Birefringence, Low confinement loss, Nonlinearity, GaP strips, Slotted cor

Bandwidth-enhanced metamaterial integrated antenna for wireless applications

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, miniaturization of the antenna size can be achieved. Different simulated antenna performance parameters such as reflection coefficients, radiation patterns, and gain are analyzed. The simulated gains of the proposed design at 1.5, 2.4, 5.8 and 10 GHz are 1.17 dBi, 2.18 dBi, 3.6 dBi, and 4.05 dBi, respectively. The proposed antenna could be a potential contender for different remote correspondence frameworks, for example, GPS, Wi-Fi, WLAN, and RADAR

A Design of a Metamaterial Integrated Triple Band Antenna for Wireless Applications

This paper represents a metamaterial (MTM) integrated antenna for multi-band operation. MTMs are integrated on the top and bottom sides of a slot-ring antenna. The basic slot-ring antenna operates at 2.4 GHz. A single complementary split ring resonator (CSRR) is placed on the ground plane and a circular shaped split ring resonator (SRR) is integrated on the top of the substrate. Integration of CSRR gives rise to a new resonant frequency at 1.5 GHz. After using SRR, a third band generates at 3.1 GHz. By using this structure, a single antenna can cover three operating bands. A microstrip line is used to feed the antenna. The triple band antenna is compact because MTM unit cells size is smaller than their wavelength used to produce resonance at a lower frequency. To analyze the performance of the proposed antenna reflection coefficient, radiation pattern, and gain are analyzed. The simulated gains are 0.71 dBi, 2.9 dBi, and 3.2 dBi corresponding to bands of 1.5 GHz, 2.4 GHz, and 3.1 GHz, respectively. The impedance bandwidths are 1.33%, 9.17%, 5.5% at the 1.5/2.4/3.1 GHz, respectively. Good separation between co- and cross-polarizations is achieved. The three operating bands at 1.5/2.4/3.1 GHz support the allotted bands for GPS, WLAN and RADAR applications

Design and performance studies of a MIMO antenna with circular polarization diversity for 5G applications

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

A 4-element MIMO antenna with orthogonal circular polarization for sub-6&nbsp;GHz 5G cellular applications

A multiple-input-multiple-output (MIMO) antenna with orthogonal circular polarization (CP) is proposed in this paper with an intention to use the antenna in sub-6\ua0GHz 5G applications. The single antenna consists of a radiating slot and feed\ua0line. The non-uniform width elliptical ring slot in the ground plane and unequal feed\ua0line technique are used to produce CP. The benefit of using ring slot antenna is that this type of antenna can radiate orthogonal CP at the front and back direction, simultaneously. The operating band of single antenna is (3.6–3.8\ua0GHz). The MIMO antenna has 4 single antenna elements where each antenna element is surrounded by the mirrored antenna elements. As a result, MIMO structure provides orthogonal CP. Moreover, this MIMO antenna can also radiate both LHCP and RHCP on the both directions (θ = 0° and 180°) simultaneously. Three interconnected strip lines on the ground plane are designed to connect the individual grounds of the antenna elements. The MIMO antenna provides good isolation and CP gain in the whole band (3.4–3.8\ua0GHz). The envelop correlation coefficient and channel capacity loss are evaluated to judge the MIMO performances and promising result is achieved. To analyze the impacts of user hand, various performance studies are done for the antenna in the vicinity of left hand and right hand phantom model and satisfactory results are achieved. These performances prepare the antenna more attractive to use in 5G cellular applications