Normally, the reported gain of the microstrip patch antenna is within 8 dBi. Using properly located three shorting pins on three bisectors, the present work reports a method to convert the non-radiating TM11 mode of equilateral triangular patch antennas (ETPAs) to a deformed TM11 radiating mode. The boresight gain of ETPA operating in TM11 mode is enhanced from −10.75 to 12.1 dBi at 5.43 GHz. The boresight measured gain is further enhanced to 14.2 dBi at 5.52 GHz by using a triangular surface-mounted short horn (SMSH) of about ${{\lambda }}/5$ height. The aperture efficiency of the ETPA with the shorting pins is 84.2%. The aperture efficiency is further improved to 94.2% using the SMSH. The measured boresight cross-polarization and side-lobe level are −40 and −29 dB, respectively. The nature of the electricfield and surface current distribution is analyzed, using both the characteristic mode analysis method and high-frequency structure simulator, to understand the role of shorting pin and coaxial feed in converting the non-radiating TM11 mode to the radiating mode. A systematic design process also is presented for a fast design of shorting pin-loaded ETPA on the suitable substrate at a specified frequency.

The study evaluated forage and livestock performance in different grazing systems over two years. Treatments were three contrasting grazing systems: (I) N-fertilized bahiagrass (Paspalum notatum Flüggé) in the summer overseeded during the winter by N-fertilized ryegrass (Lolium multiflorum) and oat (Avena sativa L.) (Grass + N); (II) unfertilized bahiagrass during the summer overseeded with ryegrass + oat and a blend of clovers (Trifolium spp.) in the winter (Grass + Clover); (III) unfertilized bahiagrass and rhizoma peanut (RP; Arachis glabrata Benth.) mixture during summer, overseeded during winter by ryegrass + oat + clovers mixture (Grass + Clover + RP). Average daily gain (ADG), gain per area (GPA), and stocking rate (SR) in the winter did not differ across treatments and averaged 0.87 kg/d (P = 0.940), 303 kg/ha, and 2.72 AU/ha. In the summer, Grass + Clover + RP had greater ADG than Grass + N (0.34 vs. 0.17 kg/d, respectively). During the summer, the GPA of Grass + Clover + RP was superior to Grass + N (257 vs. 129 kg/ha, respectively), with no difference in SR among treatments at 3.19 AU/ha. Over the entire year, ADG and GPA tended to be greater for Grass + Clover + RP. Annual SR differed between treatments, where Grass + N was greater (3.37 AU/ha) than the other treatments, which averaged 2.76 AU/ha. Integration of legumes into pasture systems in the summer and winter contributes to developing a sustainable grazing system, reducing N fertilizer use by 85% while tending to increase livestock productivity even though SR was decreased by 18%.

This research article represents the design of a simple, smaller, and novel frequency reconfigurable patch antenna for 5G communication using PIN diodes. This antenna operates in both mid-5G and high-5G bands. The antenna is intended to operate in eight distinct modes with three PIN diodes in 5G wireless communication covering 27.46–50 GHz of high-5G band (range n257/n258/n260/n261/n262) and frequencies of the 3–6 GHz of mid-5G band (range n77/n78/n79/n46). The antenna has an overall size of 20 mm × 25 mm × 1.6 mm and is placed upon a low-cost FR4 substrate. A higher radiation efficiency from 75% to 98% is achieved in all the different modes. The resonant frequencies are around 3.46, 4.43, 5.83, 31.8, 35.5, and 46 GHz in different modes of operation. Different switching statuses have been carried out in this research work and their performances have also been illustrated in the form of surface current distribution in different resonant frequencies. The simulated and measured results are compared to highlight its proposed design operation.

The novel compact size orthogonally fed 2 x 2 Multiple Input and Multiple Output (MIMO) array antenna for mid-band Fifth Generation (5G) wireless application is presented. The antenna configuration consists of diamond-shaped patches employed at the top of substrate. The V-shaped common ground slot structure is employed at the bottom of substrate. A broadband circular polarization is achieved by simply combining two circular polarization modes obtained from ground V slot and top patch feed structure. Mainly, the impedance bandwidth (IBW) and gain are enhanced by protruding slots on ground and cutting edges of patches. The measured result shows that 1.70 – 8.00 GHz (6.30 GHz) of IBW, 8.8 dBic of peak gain, and 3 dB axial ratio bandwidth from 1.81 – 3.87 GHz (2.06 GHz) are obtained. The proposed antenna performances are experimentally validated by fabricating and testing it for measured result analysis without using power divider.

As the demand for high data rates is increasing day by day, fifth-generation (5G) becomes the leading-edge technology in wireless communications. The main objectives of the 5G communication system are to enhance the data rates (up to 20 Gbps) and capacity, ultra-low latency (1 ms), high reliability, great flexibility, and enhance device to device communication. The mentioned objectives lead to the hunting of the millimeter-wave frequency range which lies from 30 to 300 GHz for 5G wireless communications. To design such high capacity, low latency, and flexible systems, antenna design is one of the crucial parts. In this paper, a survey is presented on various antenna designs with their fabrication on different types of substrates such as Rogers RT/duroid 5880, Rogers RO4003C, Taconic TLY-5, etc., at different 5G frequency bands. The different configurations of antennas that covered antenna arrays, multiple-input multiple-output (MIMO) antennas, phased antennas, and beamforming antennas are discussed in detail with their applications. The design of MIMO antennas in the 5G frequency band occupied less space so mutual coupling reduction techniques are required for maintaining the required gain, efficiency, and isolation. This paper is also focused on the mutual coupling reduction techniques and diversity in MIMO antennas.

A triple-frequency operated concentric annular ring microstrip antenna which is single fed is presented. The proposed antenna with three concentric annular rings and two symmetrical notches on its outer ring and having a cross slot in its ground surface shows triple band at resonance frequency 1.22760, 1.57542, and 2.18 GHz, respectively. At the first two bands (GPS L2 and GPS L1), circular polarization characteristic is observed and the third band observes linear polarization finding its application in Universal Mobile Telecommunication System (UMTS). The complete dimension of the antenna designed and fabricated is only 51.6 × 51.6 × 1.6 mm3. Experimental results depict the proposed antenna gain of 3.31, 3.55, and 3.50 dBi in three bands, respectively, and closely matches with the theoretical results.

The energy content of finishing diets offered to feedlot cattle may vary across countries. We assumed that the lower is the energy content of the finishing diet, the shorter can be the adaptation period to high-concentrate diets without negatively impacting rumen health while still improving feedlot performance. This study was designed to determine the effects of adaptation periods of 6, 9, 14 and 21 days on feedlot performance, feeding behaviour, blood gas profile, carcass characteristics and rumen morphometrics of Nellore cattle. The experiment was designed as a completely randomised block, replicated 6 times, in which 96 20-month-old yearling Nellore bulls (391.1 ± 30.9 kg) were fed in 24 pens (4 animals/pen) according to the adaptation period adopted: 6, 9, 14 or 21 days. The adaptation diets contained 70%, 75% and 80.5% concentrate, and the finishing diet contained 86% concentrate. After adaptation, one animal per pen was slaughtered (n = 24) for rumen morphometric evaluations and the remaining 72 animals were harvested after 88 days on feed. Orthogonal contrasts were used to assess linear, quadratic and cubic relationships between days of adaptation and the dependent variable. Overall, as days of adaptation increased, final BW (P = 0.06), average daily gain (ADG) (P = 0.07), hot carcass weight (P = 0.04) and gain to feed ratio (G : F) (P = 0.07) were affected quadratically, in which yearling bulls adapted by 14 days presented greater final BW, ADG, hot carcass weight and improved G : F. No significant (P > 0.10) days of adaptation effect was observed for any of feeding behaviour variables. As days of adaptation increased, the absorptive surface area of the rumen was affected cubically, where yearling bulls adapted by 14 days presented greater absorptive surface area (P = 0.03). Thus, Nellore yearling bulls should be adapted by 14 days because it led to improved feedlot performance and greater development of rumen epithelium without increasing rumenitis scores.

Fifth generation (5G) is the current hot topic of the world's leading telecommunication companies. The compact designs of antennas made it possible for them to resonate at higher frequencies, thus to enable the devices to attain higher data rate as compared to 4G technology. Data rate of 5G technology for low mobility users is expected to be 50.0 Gbps and for high mobility users it is 5.0 Gbps. On the other hand, International telecommunication union's objective for 5G is 3 times more spectrally efficient thanlong-term evolution (LTE). The paper has carried out meticulous study over the impact of 5G antennas on the size of antenna, size/type of substrate, gain, efficiency, and isolation, etc. Also, different arrays andmultiple input multiple outputs (MIMOs) with patch antenna, magneto electric-dipole, microstrip grid array antenna, folded dipole, series-fed array, connected antenna array, MIMO are studied. The paper also includes the existing technology i.e 4G LTE and their isolation enhancement approaches. Many of the designs used the reflector plates to reduce the back lobe radiation problem in MIMO/array antennas to increase front-to-back ratio. The gain in 5G antennas can be increased by using balun, parasitic element as directors, multiple notch structures, three identical slot sub-arrays, etc. Mathematical equations of multi-element/port antennas are included to model the designed antennas. The beam steering is also included for the 5G technology in this paper.

This paper presents the design of an elliptical shape ultra-wide band antenna for imaging of wood. The antenna is constructed comprising an elliptical shape of patch loaded by a stub to resonate at lower bands, strip loading at the back, and chamfered ground. Despite having miniaturized dimensions of 20 mm × 20 mm, the proposed antenna shows better results compared to recent studies. The simulation results depict a good ultra-wide bandwidth from 2.68 to 16 GHz, and 18.2–20 GHz. Besides, the proposed antenna has two low-frequency bands at 0.89–0.92 and 1.52–1.62 GHz, maximum gain of 5.48 dB, and maximum directivity of 6.9 dBi. The measurement outcomes are performed in air, plywood, and high-density wood and show a good agreement with the simulated results done using electromagnetic simulator CST. In addition to that, the measurement results of S-parameters, transmitted and received signals show a good agreement with the simulated results. Besides, the measured results illustrate a good isolation and uniform illumination among arrays as well as the received signals' shapes do not change in different environments, but only the amplitude. Hence, the proposed antenna seems to be adequate for microwave imaging of wood.

The proposed research paper presents the design, development, and experimental testing of a broadband stacked complementary microstrip antenna for ultra-wideband (UWB) (5.28–5.85 GHz), Unlicensed National Information Infrastructure band (UNII) (5.25–5.825 GHz), wireless local area networks (WLAN, IEEE802.11a, 5.15–5.35 GHz), and IEEE 802.11b (5.75–5.85 GHz), Worldwide Interoperability for Microwave Access band (5.25–5.85 GHz), and Radio Astronomy band (6.6–6.75 GHz) wireless applications. The main aim of this paper is to obtain an UWB behavior from the combined effect of two resonances exhibited by the driven and parasitic patches of a stacked complementary antenna geometry. Circularly polarized radiations are also emitted by the antenna by the addition of an orthogonal stub to its feed line. The proposed three-layered antenna structure (without air gap) is fabricated on commercially available glass-reinforced epoxy laminate, FR4 substrate. The topmost layer of FR4 has a square-shaped patch parasitic patch printed over it; this patch has a square slot etched out from it. The middle layer of the antenna has a square-shaped driven patch of approximately the same dimensions as that of the slot in parasitic patch. The antenna is fed using aperture-coupled feeding mechanism. Therefore the lowermost layer of FR4 has a ground plane on its top with a “π”-shaped slot etched from it and a feed line with an orthogonal stub at its bottom forming a “T”-shaped geometry. The antenna is fed by the electromagnetic coupling between the antenna layers .The proposed antenna has a compact structure with overall volumetric dimensions of 4.7 × 3.82 × 0.483 cm3. The antenna design and simulations are carried out using CSTMWSV'10 with perfect boundary (electric and magnetic) estimations. This designed antenna shows an UWB behavior from 5.14 to 5.85 GHz with an impedance bandwidth of 710 MHZ and a fractional bandwidth of 12.62% at the center frequency of band at 5.5 GHz. The radiating antenna also possesses a good gain of 4.59 dBi at the central frequency of 5.50 GHz and a 1 dB axial ratio bandwidth of 820 MHz from 5.16 to 5.98 GHz. The validation of results is done by fabrication and experimental testing of the antenna using a vector network analyzer and placing the antenna in an anechoic chamber for gain measurements. The measured results show close matching with the simulated ones and this makes the antenna well suited for the proposed wireless applications of interest, specifically in small handheld wireless communication devices.

The gas dynamic laser is numerically studied using quasi-1D and 2D simulations to investigate the effect of diamond pattern of the supersonic flow field (inhomogeneities in density field) on the laser's performance. The system of governing equations is solved with a finite volume approach using a structured grid in which the AUSM+ scheme is used to calculate the convective fluxes. Vibrational temperature of different modes, population inversion and the small signal gain are studied, and the effect of the divergent nozzle's geometry at the maximum gain is analysed.

A novel tri-band asymmetric slot with defective ground structure (DGS) microstrip antenna for dual circular polarization (CP) is proposed. By placing a slot with 45° across diagonally at the center of the patch, excites resonant bands with narrow bandwidth and dual CP operation. The main design challenge is to introduce optimized defected element of circular dumbbell shape to enhance the impedance bandwidth with frequency shift operation at all bands. DGS enabled antenna is practically fabricated and simulated. Antenna is compact in size and shows a good quality of CP at two resonant bands and linearly polarized at one band. Structure displays the impedance bandwidth of 8% (2.26–2.45 GHz), 5.45% (3.41–3.6 GHz) and 3.07% (5.12–5.28 GHz). The design also shows 40 and 11 MHz, 3-dB axial ratio bandwidth at lower and middle bands, respectively. Simulated gain for each band is 4.72, 6.2 and 4 dB. Performance of antenna with and without DGS is also studied and compared. This single probe feed proposed antenna remains consistent with good radiation patterns and sufficient antenna gain over the operating bands. Excellent agreement was obtained between measurements and simulations.

In this paper, a dual wideband microstrip antenna (MSA) has been presented for wireless local area networks (WLAN), worldwide interoperability for microwave access (Wi MaX) and U-NII band applications. The antenna is designed and simulated using CSTMWS V'10. The main goal of this paper is to get multi-frequency behavior by cutting resonant slots into the patch of the antenna and a wideband antenna behavior using an aperture coupled feeding method. The designed antenna has a semi-spiral G-shaped compact structure and an electromagnetically coupled feeding mechanism (aperture-coupled feeding). It is fabricated on an FR4 substrate with a dielectric constant of 4.4 and a dielectric loss tangent of 0.009. The testing of prototype antenna (to measure S11) is done using a vector network analyzer. The measured results are 80% matching to the simulated ones. The parametric study, simulation results, measured results, and applications of the MSA for WLAN, WiMAX, and the FCC unlicensed 5.2 GHz National Information Infrastructure (U-NII) bands are presented in the paper. The antenna shows a simulated gain of about 4.5 dB at the three wireless application bands.