Juin Acharjee

Bio: Juin Acharjee is an academic researcher from St. Thomas' College of Engineering and Technology. The author has contributed to research in topics: Antenna (radio) & Patch antenna. The author has an hindex of 5, co-authored 14 publications receiving 75 citations. Previous affiliations of Juin Acharjee include National Institute of Technology, Durgapur.

Reduction of mutual coupling and cross-polarization of a MIMO/diversity antenna using a string of H-shaped DGS

Abstract: In this article, a simple string of H-shaped defected ground structure (DGS) is used to reduce the mutual coupling and cross-polarization of a MIMO antenna. A MIMO antenna has been designed using two identical square patches to operate at the frequency of 2.4 GHz. The proposed DGS decreases the direct coupling path among the closely spaced (edge to edge gap 0.038 λ0) patches and thereby reduces the mutual coupling and cross-polarization by 46 dB and 11 dB respectively. To study the amount of mutual coupling is decoupled; a new term namely, coupling to decoupling ratio (CDR) has been defined. A mathematical model is developed using multiple polynomial regression analysis techniques to observe the dependency of CDR as a function of frequency and inter-element spacing. Also, an equivalent circuit of the DGS is constructed and validated. Diversity performance of this MIMO antenna is presented through Envelope Correlation Coefficient (ECC) and Mean Effective Gain (MEG) ratio and well acceptable values of 0.0002 and 0.03 dB are obtained respectively. A prototype is fabricated and measured. The experimental results show good agreement with that of the simulated results. Maximum peak gain of 2dBi and radiation efficiency of 74% also proves the practicality of this design.

Design of an Efficient Rectifier Circuit for RF Energy Harvesting System

Abstract: An efficient rectifier system along with an impedance matching network is proposed in this article. Impedance matching network is designed using two microstrip lines. Rectifier system for better RF to DC conversion is designed using a bridge rectifier. The proposed rectifier system provides a maximum efficiency of 50%. The impedance matching network improves the overall system performances significantly. The circuit simulator ADS 2015 is used for this system design. Performances of the proposed system are analysed using simulation results only. This proposed rectifier system along with the impedance matching network can be useful for the design of an efficient RF energy harvesting system.

Mutual coupling reduction between microstrip patch antennas by using a string of H-shaped DGS

Abstract: In this paper a novel structure is proposed to reduce the mutual coupling between two coplanar microstrip antennas which resonates at the same frequency band. A simple string of H-shaped DGS is placed in between two antennas to reduce the mutual coupling. Simulated result shows that the reduction of mutual coupling up to 50dB is achieved without affecting the radiation behavior of the antennas.

A compact printed monopole antenna with enhanced bandwidth and variable dual band notch for UWB applications

Abstract: This article presents a compact, enhanced bandwidth, and variable dual band notched printed monopole antenna for ultra wideband (UWB) applications. By inserting a simple inverted L-shaped slot in the ground plane and modifying the lower edge of the patch, wider bandwidth with usable fractional bandwidth of 139.2% (3.1–17.3 GHz) is achieved whereas two inverted U-shaped slots in the corner modified patch are embedded to realize two notch bands exactly at WiMAX (3.25–3.75 GHz) and WLAN (5.1–5.9 GHz). A precise design formula is also proposed to calculate the length of the slots. The proposed simple antenna structure with a 50 Ω feed line has been obtained within a small size of 0.11λ × 0.19λ. The simulated results are validated using measured results to show potentiality of the proposed antenna structure in UWB applications.

Wideband Four-Port MIMO antenna array with high isolation for future wireless systems

Abstract: A four-port MIMO antenna array with wideband and high isolation characteristics for imminent wireless systems functioning in 5G New Radio (NR) sub-6 GHz n77/n78/n79 and 5 GHz WLAN bands is proposed. Each array antenna element is a microstrip-line fed monopole type. The novelty of the antenna lies in loading an “EL” slot into the radiating element along with two identical stubs coupled to the partial ground in order to improve the impedance matching and radiation characteristics across the bands of interest. To further attain high port isolation without affecting the compactness and radiation performance of each antenna element, the technique of introducing an innovative un-protruded multi-slot (UPMS) isolating element (of low-profile 2 × 19 mm2) between two closely spaced antenna elements (with an edge-to-edge distance of approx. 0.03λ at 4.6 GHz) is also presented. Besides demonstrating a small footprint of 30 × 40 × 1.6 mm3, the proposed four-port MIMO antenna array has also shown wide 10-dB impedance bandwidth of 58.56% (3.20–5.85 GHz), high isolation of more than 17.5 dB, and good gain and efficiency of around 3.5 dBi and 85%, respectively, across the bands of interest. Finally, the MIMO performance metrics of the proposed antenna are also analyzed.

Decoupling of Microstrip Antennas With Defected Ground Structure Using the Common/Differential Mode Theory

Abstract: A compact structure with slot splitting meandered lines defected ground is proposed to reduce the mutual coupling between two microstrip antennas with a center-to-center distance of 0.38λ. The meandered line defected ground structure is symmetrically etched on the ground between the microstrip antennas. The proposed structure is optimized and explained by the common/differential mode theory. For experimental verification, the structure is fabricated and measured. Simulation and measurement results with excellent agreement show that the mutual coupling can be reduced significantly using the proposed structure. In addition, significant improvement is achieved in radiation efficiency, realized gain, and the decoupled array's envelope correlation coefficient.

Reduction of mutual coupling and cross-polarization of a MIMO/diversity antenna using a string of H-shaped DGS

Abstract: In this article, a simple string of H-shaped defected ground structure (DGS) is used to reduce the mutual coupling and cross-polarization of a MIMO antenna. A MIMO antenna has been designed using two identical square patches to operate at the frequency of 2.4 GHz. The proposed DGS decreases the direct coupling path among the closely spaced (edge to edge gap 0.038 λ0) patches and thereby reduces the mutual coupling and cross-polarization by 46 dB and 11 dB respectively. To study the amount of mutual coupling is decoupled; a new term namely, coupling to decoupling ratio (CDR) has been defined. A mathematical model is developed using multiple polynomial regression analysis techniques to observe the dependency of CDR as a function of frequency and inter-element spacing. Also, an equivalent circuit of the DGS is constructed and validated. Diversity performance of this MIMO antenna is presented through Envelope Correlation Coefficient (ECC) and Mean Effective Gain (MEG) ratio and well acceptable values of 0.0002 and 0.03 dB are obtained respectively. A prototype is fabricated and measured. The experimental results show good agreement with that of the simulated results. Maximum peak gain of 2dBi and radiation efficiency of 74% also proves the practicality of this design.