PIER C | PIER Journals

2023-03-20

PIER C

Vol. 131, 103-117, 2023

download: 0

Analyses of Absorbing Boundary Conditions in 2D FDTD Simulations for Electromagnetic Wave Propagation in Anisotropic Ionosphere

Md Yusoff Siti Harwani Tiem Leong Yoon

Implementing appropriate absorbing boundary conditions (ABCs) in finite-difference time-domain (FDTD) simulations is essential. Optimal ABCs can help minimize or even eliminate spurious reflections in simulations involving waves impinging on the edges of simulation grid boundaries. In this work, 2D FDTD code facilitating ABCs were implemented and incorporated under plug-and-play conditions. Using this FDTD code, two different types of ABCs were evaluated: a differential ABC and a perfectly matched layer (PML) for the anisotropic medium of the ionosphere. Furthermore, numerical experiments were conducted to examine the efficiencies of both these ABCs; a total of n = 2000 iterations were adopted, under grid conditions of 120 in the y-direction, 600 in the x-direction of spatial step, and Δx = 1000 km. Additionally, n was set as a time-equivalent variable in these simulations. For the interval Δx=1 km between any two adjacent grid points, active conditions for the grid simulation were determined within 120 km in the y-direction (vertical) and 600 km in the x-direction (horizontal). Furthermore, numerical experiments revealed that the PML platform yielded excellent efficiency, as compared with the differential ABC.

ANALYSES OF ABSORBING BOUNDARY CONDITIONS IN 2D FDTD SIMULATIONS FOR ELECTROMAGNETIC WAVE PROPAGATION IN ANISOTROPIC IONOSPHERE

2023-03-20

PIER C

Vol. 131, 89-101, 2023

doi:10.2528/PIERC23020101

download: 1

Yttria-Stabilized Zirconia Based Patch Antenna for Harsh Environment Applications

Aleks Mertvyy Md. Samiul Islam Sagar Noah Renk Praveen Kumar Sekhar Tutku Karacolak

Wireless devices that can operate under harsh environments are of great interest for military, space, and commercial applications such as antennas and radomes for fighter jets, wireless sensor networks for oil drilling and aircraft propulsion, and safety devices for first responders. Since antennas are key components of Radio Frequency (RF) Systems, it is crucial to have the antenna be able to withstand the same environmental hardships for a reliable and efficient communication. Various substrates have been utilized to implement antennas to withstand harsh environments and particularly high temperatures. Existing solutions such as silicon carbide (SiC), alumina, and polymer derived ceramics require complex deposition and patterning techniques, which make them unsuitable for low-cost RF and microwave applications. The main objective of this study is to explore microstrip patch antenna fabrication technology utilizing Zirconia Ribbon Ceramic (ZRC) materials and assess ZRC as a potential dielectric substrate for harsh environment applications. To do so, first, a wideband coplanar waveguide (CPW) fed monopole antenna is presented on ZRC substrate operating within the S band. The proposed design has been manufactured using two separate methods including a clean room sputtering process and inkjet printing. A good agreement has been obtained between the measured results of the inkjet-printed prototype and simulations. Impedance matching and radiation patterns are investigated. The inkjet printing process has been shown to be a viable and cost-effective solution for fabricating ZRC-based patch antennas.

Yttria-stabilized Zirconia Based Patch Antenna for Harsh Environment Applications

2023-03-18

PIER C

Vol. 131, 73-87, 2023

doi:10.2528/PIERC22120507

download: 2

Four Element UWB MIMO Antenna with Improved Isolation Using Resistance Loaded Stub for s , C and X Band Applications

Sumit Kumar Gupta Robert Mark Kaushik Mandal Soma Das

This article proposes a four-port multiple input multiple output (MIMO) ultra-wideband (UWB) antenna that operates across 3 to 13 GHz. Four identical fractal patches are placed orthogonally to each other. The uniqueness of the proposed design is that it does not need to incorporate any dedicated/specific design/component to realize notches within the UWB range. The elimination of notches, enhancement of bandwidth, and improvement of isolation have been achieved by integrating a resistance-loaded stub with the ground plane. The isolation between the elements was measured to be below -20 dB across the entire operating band. The fabricated prototype exhibits better diversity parameters like envelop correlation coefficient (ECC) < 0.003, diversity gain (DG) > 9.99, channel capacity loss (CCL) < 0.4 bps/Hz, and mean effective gain (MEG) < 2 dB. The proposed MIMO antenna shows omnidirectional radiation patterns with a peak gain of 5.4 dBi and radiation efficiency > 66% with required compactness having interelement (edge to edge) distance of 5.4 mm. After application of decoupling method radiation efficiency varies from 66% to 82% with gain ranging between 1.8 and 5.54 dBi. The diverse performance of the fabricated MIMO proves it to be a good candidate for UBW imaging, LTE applications, and S, C, and X band applications.

Four Element UWB MIMO Antenna with Improved Isolation Using Resistance Loaded Stub for S, C and X Band Applications

2023-03-17

PIER C

Vol. 131, 59-72, 2023

doi:10.2528/PIERC22123101

download: 2

Affordable Satellite on the Move Antenna Based on Delay-Line-PLL Phase Shifting

Ali Mohammadian Kalkhoran Seyed Hassan Sedighy

This paper presents the design methodology, simulation, and affordable implementation of a mobile digital satellite broadcasting receiver with 64 elements. The speed and range of electronic beamforming are also obtained. The proposed methodology including techniques and architecture are defined by concerning cost, commercial off-the-shelf and components, and avoidance of high-frequency circuit designs by Delay-line-PLL for phase shifting, instead of expensive RF phase shifters with complicated control buses. Choosing this architecture results in using available elements and home receivers for antenna implementation. The design results in 6-bit resolution phase shifters and ±16 degrees 2D half power electronic beam scanning range. For practical implementation feasibility, a prototype of the array is fabricated and tested, successfully. Obtaining the phase shifters' resolution and sampling of the array output power are also described. A simple and effective algorithm is proposed for grating lobes elimination, and SNR maximizing which performs the tracking task under the platform movement conditions.

Affordable Satellite on the Move Antenna Based on Delay-Line-PLL Phase Shifting

2023-03-15

PIER C

Vol. 131, 49-58, 2023

doi:10.2528/PIERC22113003

download: 10

Design and Optimization of Substrate Integrated Waveguide Bandpass Filter with T-Shape Slots Using Artificial Neural Networks

Ranjit Kumar Rayala Ramasamy Pandeeswari Singaravelu Raghavan

The present paper describes a substrate integrated waveguide (SIW) band pass filter with a T-shape slot on the upper layer, which exhibits a wide-band frequency response. The parameters of the filter are optimized by using Multi-Layer Perceptron artificial neural network (MLP-ANN) that uses Levenberg-Marquardt (LM) algorithm. A comparison is made between ANN optimized results and simulated results, and they result in minimum mean square error (MSE). A physical prototype is fabricated using printed circuit board (PCB) process, and measurements are conducted using the network analyzer. The measured results obtained agree well with the estimated ones. The filter shows a wide-band response with a transmission bandwidth of 8.96 GHz, ranging from 6.10 to 15.06 GHz with a fractional bandwidth of 81.4%. Furthermore, the insertion loss of the filter in the entire passband is varied from -0.4 dB to -0.2 dB, and the return loss is more than -10 dB.

Design and Optimization of Substrate Integrated Waveguide Bandpass Filter with T-shape Slots Using Artificial Neural Networks

2023-03-15

PIER C

Vol. 131, 35-48, 2023

doi:10.2528/PIERC23020702

download: 8

A Compact 3D Printed Mirror Folded Lens Antenna for 5G Applications

Bin Xu Bing Zhang

A concept to minimize the volume of the classic bifocal elliptical lens antenna is proposed. By applying the image theory, a reflective ground plane is placed along the short axis of a bifocal elliptical lens. An antenna-on-chip (AoC), as the lens's feed source, is placed at the upper focus and packaged by the lens body. The AoC radiates toward the ground plane instead of the free space. The geometric optics (GO) ray tracing analysis shows that the optical path of the miniaturized monofocal integrated lens antenna (ILA) is equal to that of the classic bifocal ILAs, so the gain is almost unaffected on the basis of the lens' volume reduction. For the quantitative evaluation of the gain loss caused by feed occlusion, a set of analytical equations is given. To verify the design concept, a 26 GHz miniaturized self-packaged monofocal elliptical ILA is designed and fabricated by 3D printing technology. The ILA achieves a 26.5 dBi gain and a size reduction rate of 38% compared with the classic bifocal elliptical lens. Moreover, the ILA also functions as the package for the AoC's die. The proposed design concept can not only reduce the volume of the classic bifocal elliptical lens dramatically but can also save the effort and cost to package the AoC's die in a highly integrated system, which is believed to have great potential to create large profit margins for the fifth-generation (5G) mobile network applications.

A Compact 3D Printed Mirror Folded Lens Antenna for 5G Applications

2023-03-14

PIER C

Vol. 131, 25-33, 2023

doi:10.2528/PIERC22122106

download: 8

A Wideband Circularly Polarized CPW-Fed Diamond Shape Microstrip Antenna for WLAN/WiMAX Applications

Sonu Rana Jyoti Verma Anil Kumar Gautam

This paper presents the design and fabrication of a wideband circularly polarized CPW-fed compact diamond-shaped antenna. To enhance the wideband response and axial ratio in the desired frequency band, the geometry of the proposed antenna is modified. The modified antenna consists of one radiating element that includes two slits and one horizontal rectangular stub and an improved ground plane. The suggested wide-band antenna has overall measurements of 25 mm x 28 mm x 1.6 mm. The V-shaped slit generates two orthogonal modes in the proposed antenna to excite circular polarization. The rectangular stub improves the wideband response in 2.35-4.62 GHz. The fabricated prototype antenna demonstrates good consistency between simulation and measured results. The suggested antenna resonates over a 2700 MHz transmission bandwidth between 2.35 and 4.62 GHz, making it a good choice for WLAN and WiMAX applications. The average gain in the wideband is 3.1 dBi. It is shown that our suggested approach is a great choice for developing any wideband microstrip antenna for usage in a variety of wireless communication systems.

A Wideband Circularly Polarized CPW-fed Diamond Shape Microstrip Antenna for WLAN/WiMAX Applications

2023-03-11

PIER C

Vol. 131, 13-24, 2023

doi:10.2528/PIERC23012806

download: 7

Compact 4-Port Vivaldi MIMO Antenna for 5G Wireless Devices

Golla Ramyasree Nelaturi Suman

In this paper, a novel compact 4-port Vivaldi Multiple Input Multiple Output (MIMO) antenna is proposed for 5G wireless devices. The presented antenna has dimensions 40x40x1.6 mm³. The suggested antenna is fabricated on RT/Duroid dielectric material with dielectric constant of 2.2. The orthogonal arrangement of antenna elements and embedding slits between them result in enhanced isolation. The gain observed for the proposed antenna is 2.405 dB. The diversity performance of MIMO structure in terms of Envelop Correlation Coefficient (ECC < 0.02), Total Active Reflection Coefficient (TARC < -10 dB), Diversity Gain (DG > 9.998), Channel capacity Loss (CCL < 0.4) and Mean Effective Gain (MEG < 1 dB) is studied and analyzed. The simulated and measured results are in good agreement.

Compact 4-port Vivaldi MIMO Antenna for 5G Wireless Devices

2023-03-06

PIER C

Vol. 131, 1-12, 2023

doi:10.2528/PIERC23011902

download: 4

Investigation on a Small 4T4R MIMO Microstrip Antenna for Sub-6 GHz New Radio Wireless Network

Satya Singh Milind Thomas Themalil

The next generation 4T4R Multiple Input Multiple Output (MIMO) antenna solution is gradually accepted by operators in many countries as a mainstream expansion to long term evolution (LTE) networks. Using limited spectrum and high capacity, operators have successfully adopted multi-sector 4T4R MIMO deployment and achieved a 70% increase in capacity without increasing spectrum, thus paving way for state of art next generation wireless networking environment requiring antennae that are robust, small size, lighter, preferably with circular polarization. MIMO antennae provide optimality by arresting multipath fade effect and ensuring data link that is reliable. MIMO realizes efficiency in mobility with increase in capacity of links and several sub-bandwidths using polarization diversity providing better cybersecurity. This work therefore is an investigation on a small size 4T4R MIMO antenna for the use in a sub-6 GHz new radio (NR) band in a fading environment with good inter element as well as radiation isolation compared with earlier research. A rectangular patch with loaded slots is designed to obtain small size. Stubs and parasitic elements are introduced between the elements for better mutual coupling performance. Performance of the antenna is stable, with the test results agreeing. The parametrics follow the coefficient of transmission isolation technique to obtain an optimal envelope correlation coefficient.