Wide Band Research Articles

Numerical Simulation and Evaluation of Y\(_2\)S\(_3\) and Y\(_2\)TeS\(_2\) on Structural, Stability, and Electronic Properties for Photocatalytic Water Splitting Applications

We attempt to establish a computational insight into the structural, mechanical, dynamic, electronic, and photocatalytic properties of orthorhombic phase Yttrium sulphide Y\(_2\)S\(_3\) and Y\(_2\)TeS\(_2\) Janus compounds by density functional calculations. The Janus Y\(_2\)TeS\(_2\) is a hypothetical compound with all properties computed forthe first time. Computed lattice parameters for Y\(_2\)S\(_3\) are in reasonable agreement with available experimental data. Mechanical properties are investigated by calculating the elastic constant to check for Born stability criteria. A finite displacement vibrational frequency study confirmed that Y\(_2\)S\(_3\) and Y\(_2\)TeS\(_2\) are stable; negative phonon frequencies were checked. Computed PBEsol and MBJ band structures found that Y\(_2\)S\(_3\) is a direct band gap semiconductor, while Y\(_2\)TeS\(_2\) is an indirect band gap semiconductor. Band gaps estimated from the HSE06 hybrid functional are 2.75 eV and 2.70 eV for Y2S2 and Y\(_2\)TeS\(_2\), respectively, suggesting that they are semiconductor materials with wide band gaps that can absorb light in the ultraviolet region. Mullikan’s electronegativity screen technique, used to calculate valence band maximum VBM and conduction band minimum CBM potentials, predicted that Y2S3 and Y\(_2\)TeS\(_2\) have suitable conduction band minimum potential of -1.05 V and -1.30 V and valence band maximum of 1.70 V and 1.40 V, respectively, versus normal hydrogen electrode (NHE) at PH = 0 to trigger the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) simultaneously.

ИСПОЛЬЗОВАНИЕ ИК- И ЭЛЕКТРОННОЙ СПЕКТРОСКОПИИ ДЛЯ АНАЛИЗА АКТИВАТОРА ПЕСТИЦИДОВ И АГРОХИМИКАТОВ

The purpose of the study is to evaluate the capabilities of IR and electron spectroscopy methods for analyzing the organosilicon activator of pesticides and agrochemicals based on polyalkylene oxide siloxane and determining its residual quantities on grape bunches during the harvest season. The objects of research are Aligote and Cabernet Sauvignon grape varieties, the organosilicon adjuvant Atomic and its model mixtures with distilled water, as well as grape rinsing water. The analysis was carried out using electron spectroscopy and Fourier transform infrared spectroscopy using an attenuated total internal reflection (ATR) attachment with a diamond element. It has been shown that in the Atomic IR spectrum there is a very strong characteristic absorption band of stretching vibrations of the Si–O and C–O bonds at 1077 cm-1, which may be a marker of the presence of this adjuvant in its mixtures with water. A wide absorption band for stretching vibrations of O–H bonds was also found at 3389 cm-1. The absorption band of stretching vibrations of the Si–O and C–O bonds of the Atomic adjuvant is observed in the IR spectra of its mixtures with water up to a ratio of 1:69 (by volume). In the Atomic electronic spectrum, absorption maxima were found at 276 and 310 nm. The absorption maximum at ≈270 nm remains with further dilution, but is practically no longer visible in the spectrum of the Atomic mixture with water in a ratio of 1:500 (by volume). Under experimental conditions, IR and electron spectroscopy methods did not reveal any residual amounts of the Atomic adjuvant in the rinsing water from Aligote and Cabernet Sauvignon grape varieties pre-treated with it. The results obtained can be used in the analysis of the Atomic activator and other products based on polyalkylene oxide siloxane in various mixtures used in agriculture for treating plants.

All-Organic Aramid Films with High Temperature Resistance and Electrical Insulation by Introducing Interfacial Hydrogen Bonds.

Although aramid nanofibers (ANFs) consist of rigid poly(terephthalic acid terephthalamide) molecular chains with good high temperature resistance for aerospace and other high-temperature applications, it has poor electrical insulation properties due to internal defects. Currently, the main method to improve the electrical insulation properties is to introduce wide band gap two-dimensional (2D) fillers, such as Boron Nitride Nanosheets (BNNS) or mica flakes, but this inevitably affects the mechanical properties and optical transparency. Cellulose acetate (CA) is originated from acetylation of natural cellulose, and the higher number of hydrogen bond donors on the molecular chain enables it to interbond with many polymers. In this study, CA was introduced into ANFs films, and the all-organic aramid films were prepared by blade coating method. A high dielectric constant of 14.4 as well as a low dielectric loss (0.062 @103 Hz) were obtained, and the dielectric loss of all films was lower than that of the ANFs films, which is attributed to the introduction of interfacial hydrogen bonds that suppressed the loss. In addition, the introduction of interfacial hydrogen bonds introduced deep traps inside the all-organic aramid films, which further improved in breakdown strength from 216.11 MV/m for ANFs film to 367.8 MV/m for the 5 CA film. The prepared all-organic aramid films also showed excellent flexibility as well as high temperature resistance, and the electrical insulation performance under different extreme environments was still higher than that of the ANFs films. This study provides a method for the preparation of high temperature resistant and electrically insulating films, which have great potential applications in fields relating to high temperature circumstance.

Interlayer Parallel Connection of Multiple Helmholtz Resonators for Optional Broadband Low Frequency Sound Absorption

The Helmholtz resonance acoustic metamaterial is an effective sound absorber in the field of noise reduction, especially in the low-frequency domain. To overcome the conflict between the number of Helmholtz resonators and the volume of the rear cavity for each chamber with a given front area of single-layer metamaterial, a novel acoustic metamaterial of interlayer parallel connection of multiple Helmholtz resonators (IPC–MHR) is proposed in this study. The developed IPC–MHR consists of several layers, and the Helmholtz resonators among different layers are connected in parallel. The sound absorption property of IPC–MHR is studied by finite element simulation and further optimized by particle swarm optimization algorithm, and it is validated by standing wave tube measurement with the sample fabricated by additive manufacturing. The average sound absorption coefficient in the discrete frequency band [200 Hz, 300 Hz] U [400 Hz, 600 Hz] U [800 Hz, 1250 Hz] is 0.7769 for the IPC–MHR with four layers. Through the optimization of the thickness of each layer, the average sound absorption coefficient in 250–750 Hz is up to 0.8068. Similarly, the optimized IPC–MHR with six layers obtains an average sound absorption coefficient of 0.8454 in 300–950 Hz, which exhibits an excellent sound absorption performance in the low-frequency range with a wide band. The IPC–MHR can be used to suppress obnoxious noise in practical applications.

Dual Horn MIMO antenna using SIW technology for mmWave high speed vehicular communication

Abstract The current research investigation proposes solutions for the high speed,
high data rate, reliability and high penetration losses using substrate-integrated waveguide
(SIW) optimized horn antenna technology. A dual horn MIMO antenna with the
cavity holes is designed using multilayer substrates Rogers/Duroid 5880 and Rogers
RO3003 of size 56.31×35.06×1.54 mm3 and it provides wide band frequency range of
26.63 - 35.30 GHz. The critical design parameters and their impact are also included
here. The gain and radiation efficiency in the band are 6.94 - 8.93 dBi and 96.1 %-98%
respectively. The proposed H-plane dual horn MIMO antenna is able to receive signals
in all directions in this research. The ECC is 0-0.002 and the TARC is 8.69 GHz in
the band. The CCL in the band is less than 0.5 as per ITU. The impact of MEG using
isotropic and Gaussian environments and multipath propagation w.r.t.NLOS are also
carried out in this research.

A comprehensive review of yttrium aluminum nitride: crystal structure, growth techniques, properties, and applications

YAlN has emerged as a wide band gap semiconductor with high potential to compete with ScAlN in industrial applications. Theoretical predictions about YAlN’s material properties have been the main motivation for conducting experimental investigations and verify simulated results. However, several challenges have been faced in experimental studies on YAlN that contradict theoretical data, especially when trying to reach higher alloy concentrations. This work presents a systematic review analyzing different material properties including structural characterization, elastic properties, and thermal features. It combines all available experimental data on the growth and reported material parameters, such as band gap, lattice parameters, and electrical properties with the aim of introducing a new motivation to further study YAlN’s potential in various fields of device applications. The review provides a comprehensive overview on the current state of knowledge on YAlN, highlighting the discrepancies between theoretical predictions and experimental results. By providing information from multiple studies, this work offers valuable insights into the challenges and opportunities associated with YAlN development, paving the way for future research directions and potential industrial applications of this promising wide band gap semiconductor.

An Analysis of Rock Bolt Dynamic Responses to Evaluate the Anchoring Degree of Fixation

Rock bolting in underground environments is used for different fundamental reasons, including suspending potentially loosened blocks, clamping small wedges together, inducing a protective pressure arch along the contour of excavated voids to improve the self-supporting capacity of the ground, and providing passive pressure in integrated support systems. In this study, we describe a testing procedure that was developed to investigate the grouted annulus of a rock bolt using a low-cost investigation method. This diagnostic technique was based on the dynamic response of the system, where mechanical vibrations were induced within the rock bolt and the response was recorded by using geophones/accelerometers on the protruding element of the bolt (the collar and head). The collected signal was then processed to estimate the spectral response, and the amplitude spectrum was analyzed to detect the resonance frequencies. A 3D finite element model of the rock bolt and grouting was established to simulate the quality of the coupling by varying the mechanical properties of the grouting. The model’s response for the studied geometry of the rock bolt suggested that a poor quality of grouting was usually associated with flexural modes of vibration with a low resonance frequency. Good-quality grouting was associated with a frequency higher than 1400 Hz, where the axial vibration was mainly excited. Our analyses referred to short rock bolts, which are usually adopted in small tunnels. The interpretation of the experimental measurements assumed that the spectral response was significantly affected by the quality of the grouting, as demonstrated by the modeling procedure. The resonant frequency was compared with the results of the model simulation. The method was used to test the quality of rock bolts in a small experimental tunnel carved from andesite rock in Chile. Low-cost shock sensors (piezoelectric geophones) with low sensitivity but a wide frequency band were used. The main research outcome was the development of a reliable method to model the dynamic response of rock bolts in mines or for experimental applications in tunnels. Albeit limited to the current specific geometries, the modeling and testing will be adapted to other anchor/bolt options.

How sea ice affects edge waves in the Sea of Okhotsk

Long-term observations, which were collected in the Sea of Okhotsk coastal zone under open-water conditions and at times when the sea was ice-covered from mid-January to mid-March 2022, are interpreted. The project augments preceding work using three synchronously-recording, seafloor-mounted, pressure transducers sampling at 1 Hz to acquire time series of inshore wave oscillations. Units are deployed nearer to the shore and closer together than was done during the previous studies. Spectral analyses of open-water sea level oscillations perpendicular to the coast reveal a wide band of energy, suggestive of a propagating edge wave at about 5-min period with an offshore-to-inshore gain up to 1.5. Similar wave characteristics occur alongshore. Intriguingly, the peak edge wave period at 5 min migrates to 6–7 min when the sea becomes covered with ice, and narrower bands at periods from 0.5 to about 3 min emerge. Other period ranges also appear to be affected by the onset, presence and eventual disintegration of sea ice. Whilst a shift of the dominant edge wave period can be attributed to changes in spectral refraction arising from the incoming swells being low-pass filtered by sea ice, because of the observed tidal signal it is speculated in this case that the observed period adjustment and attendant expansion of bandwidth may also be associated with instability around the fundamental frequency. The potential for edge wave solitons to exist is explored.

Exploring the potential of Wide Band Gap semiconductors in renewable energy system applications: A critical review

Exploring the potential of Wide Band Gap semiconductors in renewable energy system applications: A critical review

Highly Selective Ultra-wideband Filtenna with Triple Band Notch and Wide Stop Band Rejection for UWB Communication and Sensing Applications

A compact and highly selective monopole ultra-wideband (UWB) filtenna (UFA) having triple band notch is presented in this paper. The proposed UFA covers the UWB frequency range with good matching characteristics. Defected ground structure provides good impedance matching with return loss above 10 dB. A low pass filter with wide stop band rejection is integrated in the feed line to provide high selectivity and wide rejection band at upper edge of UWB. Three folded uniform impedance resonators are integrated with the UWB radiator to suppress the effect of interference experienced in the UWB spectrum from WiMAX, WLAN, and X-bands. The proposed UFA covers the frequency bandwidth from 2.5 to 11.1 GHz with above 3 dBi gain in all the pass bands and radiation nulls at notch bands. The proposed design has been simulated and analyzed using commercially available software CST Microwave Studio and the obtained results show good agreement between simulation and measurement. The performance of this UFA makes this a suitable candidate for UWB communication and sensing applications.

Compact wide band quad element MIMO antenna with inbuilt isolator for 5G applications

Abstract A compact quad-element multiple-input multiple-output (MIMO) antenna with self-isolation and pattern diversity features for 5G applications has designed in this article. In the proposed MIMO antenna design, drop-shaped slots have been cut from the ground plane to attain wide bandwidth of 1 GHz in the operating band 3.3-4.3 GHz of near radio (NR-77) band for 5G applications. Further, a criss-cross shaped isolator is formed after integrating four single wideband antenna elements with different orientations in the ground plane. This shape is responsible for high self-isolation of 25 dB in the desired band of 5G. Further, the 2-D radiation pattern of the MIMO antenna has pattern diversity characteristics with a high peak gain of 6 dB in the working band, which validates the proposed work for the 5G MIMO application. The diversity performance of the proposed MIMO antenna has been validated with measured envelope correlation coefficient of 0.0002, diversity gain of 10 and channel capacity loss is below 0.5 bits/sec/Hz across the entire frequency band. Furthermore, simulation studies have been demonstrated for different practical applications such as housing, automotive and on body for practical utility of proposed prototype.

A Broadband Mode Converter Antenna for Terahertz Communications

The rise of artificial intelligence (AI) necessitates ultra-fast computing, with on-chip terahertz (THz) communication emerging as a key enabler. It offers high bandwidth, low power consumption, dense interconnects, support for multi-core architectures, and 3D circuit integration. However, transitioning between different waveguides remains a major challenge in THz systems. In this paper, we propose a THz band mode converter that converts from a rectangular waveguide (RWG) (WR-0.43) in TE10 mode to a substrate-integrated waveguide (SIW) in TE20 mode. The converter comprises a tapered waveguide, a widened waveguide, a zigzag antenna, and an aperture coupling slot. The zigzag antenna effectively captures the electromagnetic (EM) energy from the RWG, which is then coupled to the aperture slot. This coupling generates a quasi-slotline mode for the electric field (E-field) along the longitudinal side of the aperture, exhibiting odd symmetry akin to the SIW’s TE20 mode. Consequently, the TE20 mode is excited in the symmetrical plane of the SIW and propagates transversely. Our work details the mode transition principle through simulations of the EM field distribution and model optimization. A back-to-back RWG TE10-to-TE10 mode converter is designed, demonstrating an insertion loss of approximately 5 dB over the wide frequency range band of 2.15–2.36 THz, showing a return loss of 10 dB. An on-chip antenna is proposed which is fed by a single higher-order mode of the SIW, achieving a maximum gain of 4.49 dB. Furthermore, a balun based on the proposed converter is designed, confirming the presence of the TE20 mode in the SIW. The proposed mode converter demonstrates its feasibility for integration into a THz-band high-speed circuit due to its efficient mode conversion and compact planar design.

Predicting Perovskite Photovoltaics Performance.

Wide band gap FA0.8Cs0.2Pb(I0.6Br0.4)3 perovskite photovoltaic (PV) devices are measured by spectroscopic ellipsometry in the through-the-glass configuration and analyzed to determine the complex optical property spectra of the perovskite absorber as well as the structural properties of all constituent layers. This information is used to simulate external quantum efficiency (EQE) spectra, to calculate PV device performance parameters such as short circuit current density, open circuit voltage, fill factor, and power conversion efficiency, and to develop strategies for increasing the accuracy of predictions. Simulations and calculations tend to overestimate PV device performance parameters, undermining the accuracy and usefulness of those simulations. Mapping spectroscopic ellipsometry measurements of an incomplete device are also collected from the perovskite film side to obtain layer thicknesses, perovskite band gap energies, and Urbach energies at each mapping point. The incomplete device stacks feature the perovskite absorber as the final deposited layer, while the complete devices add electron transport layers and silverback electrical contacts. When simulations are based on structural and optical properties obtained from spectroscopic ellipsometry measurements of incomplete PV device stacks, further inaccuracies arise as characteristics of the exposed perovskite film are not necessarily the same as those of an absorber in a complete, protected PV device. Predictions for PV performance parameters fall within 5% of the experiment for three of four baseline devices. The usefulness of this is apparent in situations where experimentally measuring PV device performance is unfeasible or overly tedious, as well as during intermediate steps during production.

Periodic gradient duplexcavity meta-lens for wide-band directional acoustic beaming

Abstract Selective multi-directional sound projection across a wide-band low mid-frequency range remains a significant challenge in acoustic applications, primarily due to the manipulation of long wavelengths within compact acoustic meta-lens. This study introduces a novel directional acoustic beaming theoretical method, specifically a duplexcavity four-lobe valve-shaped acoustic meta-lens (DFVAM). By manipulating geometric parameters, the DFVAM effectively controls downstream acoustic in a directional sound projection fashion that enhances sound wave propagation across multiple wide frequency bands. Experimental results validate substantial sound focusing at frequencies of 4500–4800 Hz, 7200–7600 Hz, 9700–10 300 Hz, and 11 400–11 600 Hz, achieving sound beam lengths between 12 and 21 λ, cross-sectional areas ranging from 0.7 to 2 λ, and FWHM values of 0.140–0.218 m. This meta-lens offers efficient acoustic modulation and focusing across various frequency ranges, presenting promising applications in acoustic directional transmission, sound energy collecting and acoustic levitation.

Topologically Streamlined Single Feed Wide Band Circular Polarized Antenna

A single feed circularly polarized (CP) microstrip hexagonal open loop monopole antenna with defective ground plane is introduced in this article. The antenna is made up of an open hexagonal loop excited by a 50Ω microstrip feed line, ground defected by a curved structure with two slots and a “U” shaped slit etched below the microstrip feed line. The optimized designs are verified experimentally for reflection coefficient, axial ratio bandwidth, realized gain and radiation patterns. Results of the measurement indicate that the proposed antenna attains a wide impedance bandwidth of 103% (2.5–7.8 GHz), axial ratio bandwidth of 83% (2.9–7 GHz) and peak gain of 3.5 dBi. The proposed radiator’s novelty stems from the blend of uncomplicated geometry and single-point-fed excitation with broadband CP characteristics having a compact size of only 0.149λ0 at the lowest CP frequency. The suggested antenna is an appropriate one for various wireless communication applications like WLAN, Wi-MAX, Aeronautical Radio Navigation band and C band applications. Exhaustive studies indicate superior performance of the suggested antenna as compared with the state-of-the art designs.

A wide band circularly polarized antenna using meta surface for Wi-Fi applications

Abstract A circularly polarized, single-feed, low-profile patch antenna with enhanced gain and bandwidth for WI –FI applications is presented in this paper. The proposed antenna has a slot-loaded square patch (SLSP) is placed between reactive impedance structure (RIS)-based metasurface (MS) and the ground plane. A 6x6 circular RIS metasurface is used to improve the gain, impedance and axial ratio bandwidth. The antenna prototype’s overall dimensions are 60mm x 60mm x 3.6mm.The measured impedance bandwidth (IBW) of the proposed antenna is 26% (4.98GHz–6.48GHz) which covers the 5GHz (5.150-5.850 GHz) and 6GHz (5.950 – 7.125 GHz) frequency bands of wireless spectrum. The antenna exhibits right hand circular polarization with maximum measured gain of 6.5 dBic and the 3-dB ARBW is 5.23% (5.47GHz–5.77GHz).

Structural, elastic, electronic, magnetic and thermal properties of X3FeO4 (X = mg, ca and Sr) materials

This prediction evaluates the different physical characteristics of magnetic materials X3FeO4 (X = Mg, Ca and Sr) by using density functional theory (DFT). The generalized gradient approximation (GGA) approach is chosen to define the exchange and correlation potential. The structural study of the compounds X3FeO4 (X = Mg, Ca and Sr) shows that the ferromagnetic phase is the more stable ground state, where all the parameters of the network are given at equilibrium. The calculated elastic constants confirm their stability in the cubic structure. The electronic characteristics calculated using the GGA and GGA + U approaches prove that all these compounds are semi-metallic with a wide band gap (EHM) and a high Curie temperature (TC). Furthermore, the magnetic moments of the studied compounds are calculated in order to claim their half-metallicity behavior. The p-d hybridization between the 3d-Fe and 2p-O states generates weak magnetic moments in the non-magnetic X and O sites, and decreases the Fe atomic moment relative to its free space charge of 4 µB. The thermal parameters including the thermal expansion coefficient, the heat capacity at constant volume and the Debye temperature were calculated for these compounds.

Periodically poled aluminum scandium nitride bulk acoustic wave resonators and filters for communications in the 6G era

Bulk Acoustic Wave (BAW) filters find applications in radio frequency (RF) communication systems for Wi-Fi, 3G, 4G, and 5G networks. In the beyond-5G (potential 6G) era, high-frequency bands (>8 GHz) are expected to require resonators with high-quality factor (Q) and electromechanical coupling (kt2) to form filters with low insertion loss and high selectivity. However, both the Q and kt2 of resonator devices formed in traditional uniform polarization piezoelectric films of aluminum nitride (AlN) and aluminum scandium nitride (AlScN) decrease when scaled beyond 8 GHz. In this work, we utilized 4-layer AlScN periodically poled piezoelectric films (P3F) to construct high-frequency (~17–18 GHz) resonators and filters. The resonator performance is studied over a range of device geometries, with the best resonator achieving a kt2 of 11.8% and a Qp of 236.6 at the parallel resonance frequency (fp) of 17.9 GHz. These resulting figures-of-merit are (FoM1=kt2Qp and FoM2=fpFoM1×10−9) 27.9 and 500, respectively. These and the kt2 are significantly higher than previously reported AlN/AlScN-based resonators operating at similar frequencies. Fabricated 3-element and 6-element filters formed from these resonators demonstrated low insertion losses (IL) of 1.86 and 3.25 dB, and −3 dB bandwidths (BW) of 680 MHz (fractional BW of 3.9%) and 590 MHz (fractional BW of 3.3%) at a ~17.4 GHz center frequency. The 3-element and 6-element filters achieved excellent linearity with in-band input third-order intercept point (IIP3) values of +36 and +40 dBm, respectively, which are significantly higher than previously reported acoustic filters operating at similar frequencies.

Thin profile UWB antenna with improved bandwidth for wearable applications

Abstract This work investigates a compact tapered Coplanar Waveguide (CPW) fed wearable antenna. The wide band antenna incorporates a modified patch inspired by a flower shape and a semi-elliptical ground plane to realize a wide bandwidth. The flower-shaped geometry is implemented to increase the electrical perimeter of the radiating element to improve impedance bandwidth. The antenna design is also elaborated by mathematical and analytical modeling. The antenna prototype is printed on a thin FR-4 (0.0026 λ thick) substrate with an overall footprint of 0.21 λ x 0.28 λ (where λ is the lower operating wavelength of the proposed structure, i.e., f = 3.95 GHz). The measured results, like reflection coefficient, far-field plots, and gain, are compared with the simulated results. The measured bandwidth is 19.92 GHz with a gain of 3.9 dBi. An investigation is carried out underwater to analyze the performance of the antenna in wet conditions. Specific Absorption Rate (SAR) is calculated to ensure the safety of human tissue with antenna proximity. The maximum SAR observed is 0.844 W/kg, within the acceptable limit. Thus, the reported results validate the application of the proposed antenna for wearable devices and sensors.

Wide band circularly polarized antenna for GNSS signals detection

Abstract In this paper, the design and optimization of a circularly polarized antenna based on two crossed dipoles in phase quadrature for Global Navigation Satellite System (GNSS) wide band application has been investigated. The proposed design is single fed and relies on parasitic structures to achieve wide band coverage on the GPS standard bands L1 (1559–1610 MHz) and L5 (1164–1189 MHz). Full-wave simulations have been used to compute the radiation properties and the impedance of the antenna. A prototype was manufactured, and good agreement has been observed between the simulated results and measurement for both radiation pattern and reflection coefficient. The antenna achieves a −10 dB impedance bandwidth of $56.97\%$ covering the band 1164–1610 MHz, and an axial ratio that covers the L5 band ranging between 7 dB and 2.8 dB from 1.164 GHz to 1.3 GHz while maintaining a value below 2.7 dB across the entire L1 band. The antenna occupies a volume of $\,99\, \,\times\,99\, \times 50$ mm3. It has been tested in real conditions during the 23rd French National Microwave Days (JNM) student competition. A GNSS signal receiver has been connected to the antenna. The antenna has been evaluated based on the number of connections it could achieve over a duration of 30 s.