Antenna Height Research Articles

Special features of the architecture of 5G networks. Probabilistic forecasting of the impact of electromagnetic fields of radio frequencies on the population (literature review)

Introduction. The Russian telecommunications industry is on the threshold of introducing 5G/IMT-2020 (5G) mobile communications. The expected technological innovations of the new generation standard will lead to an increase in the capacity of mobile operators ‘ networks, data transfer speeds, the emergence of new scenarios for the use of mobile communications and the development of innovative digital services. This will contribute to economic growth by increasing labour productivity, automation and introducing new technologies in various economy and human activity areas. At the same time, the electromagnetic environment (EMO) in the areas where people stay will also change. The purpose of the study is to consider the unique features of the architecture of the 5G network to predict the impact on the population of electromagnetic fields (EMF) of the radio frequency (RF) range. Material and methods. The study is analytical. The information base of the research was Russian strategic documents on the development of 5G technologies, articles published in domestic and foreign journals. Results. The primary input data for the construction of 5G networks are presented, allowing us to evaluate EMO and identify the new technology features that are significant in terms of the impact of RF electromagnetic fields on the population. The 5G network uses previously unused RF bands and new types of antennas. With the introduction of 5G, the density of base stations (BS) and access points will significantly increase, the heights of BS antennas will decrease, and the spatial and temporal characteristics of electromagnetic radiation will change substantially. Conclusion. The architecture of the 5G network differs significantly from the mobile communication standards of previous generations. The introduction of 5G networks will lead to a significant change in the electromagnetic background in the environment. An urgent task is to develop a theory of hygienic regulation of RF EMF for the population in a complex electromagnetic environment with simultaneous operation of 5G networks and previous generations and new approaches to determining the levels of EMF in the environment by computational and instrumental methods.

Correction to: Development of a GNSS‑IR instrument based on low‑cost positioning chips and its performance evaluation for estimating the reflector height

Global Navigation Satellite System interferometric reflectometry (GNSS-IR) can be used to monitor a series of geophysical parameters in a cost-effective manner with high temporal resolution. The technique makes use of the simultaneous reception of direct and reflected GNSS signals with a single antenna. Based on the low-cost u-blox M8N chips, a GNSS-IR instrument is developed, which could be used to collect and process GNSS signals automatically and save and transmit generated GNSS data. Details about the instrument are described here for the first time. Then, the recorded SNR observation characteristics are analyzed by comparing three in-situ SNR sequences, which are simultaneously collected by the instrument with a low-cost patch antenna and a geodetic antenna and by a geodetic GNSS receiver with a geodetic antenna. Based on the developed function relating the peak power spectral density to peak frequency estimation error of the low-cost instrument, a weighting method is proposed to fuse multiple estimations of the reflector height to improve the estimation accuracy of the GNSS-IR-based reflector height. The performances of the developed low-cost instrument and the proposed reflector height estimation method are evaluated using a data set collected in Xinxiang City, Henan, China, over 6 days. The results show that there exists good agreement between the instrument-based reflector height estimates and the ground-truth estimates, with root-mean-square errors of 1.1 cm and 0.4 cm for the normal average and the proposed weighted average results, respectively, when the antenna height is in the range of 0.65 m to 2.15 m and the reflecting surface is flat, silty loam soil ground.

Measurement and Prediction of Received Signal Level and Path Loss through Vegetation

This paper presents the measurement and prediction of received signal level and path loss through vegetation. Results were estimated under free space, single tree, and vegetation conditions which revealed that the presence of isolated trees along a radio path can affect signal propagation leading to reduction in signal strength (attenuation). The attenuation was found to be dependent on many factors and parameters of the trees e.g. Geometry of measurement, (either trunk or canopy path), state of trees foliation, frequency, canopy thickness among others. In the measured data, high loss values were recorded at canopy geometry which is due to high presence of interacting and attenuating elements at the canopy. Also, high variation in Received signal strength (RSS) was noted at canopy geometry. However, the trend shows variation from path to path. The main factor is the density of tree parameters along the chosen path. Depending on the density of tree parameters along the chosen path, the depth dependence may be extremely slow as seen in the measure data. With this evidence, for radio communication inside woodlands or forests, localizing the two nodes inside the vegetation will certainly give overall best performance in terms of signal impairment. The propagation mechanism in each case are the same at the antenna geometries used following the trend of signal decay. Different transmit antenna inclination angles were used and this has not shown any significant contribution to the excess loss. However, antenna height with respect to the trees canopy showed significant contribution to the excess loss. This information will be useful to network planning engineers in link budget estimation.

Miniaturization of Monopole Antenna Based on Spoof Surface Plasmon Polaritons

The development of communication technology and the expansion of spectrum have brought the urgent demand for antenna miniaturization. In this letter, a method of miniaturizing the monopole antenna, which is based on the deep-subwavelength property of the spoof surface plasmon polaritons (SSPPs), is proposed. The SSPP monopole antenna is composed of an SSPP structure and an interdigit capacitor near the feeding structure for impedance matching. The antenna height is determined by engineering the dispersion curves of the SSPPs. The SSPP structure is fed by an SMA connector whose ground is connected to a finite circular metal plate. For verification, an SSPP antenna working at around 2.4 GHz is designed, fabricated, and measured. The profile of the SSPP monopole antenna is reduced to 11.7% of the wavelength in free space. The simulation and experimental results both show that the low-profile SSPP antenna has high-efficiency omnidirectional radiation with low cross polarization in the operating band. The peak gain at 2.4 GHz is up to 4.59 dBi. This letter provides an effective alternative to design a low-profile monopole antenna and has great potential in the miniaturization of the antenna.

낮은 안테나 높이 및 균일한 이득 특성을 갖는 초광대역 네 개의 팔을 갖는 후방 공동 시뉴어스 안테나

In this study, an ultra-wideband cavity-backed four-arm sinuous antenna with low height and wide gain bandwidth is proposed. To reduce the antenna height, a feeding structure is applied with a coaxial bundle and two-port balun. In addition, a multi-layer radio absorber and metallic cavity are applied to obtain certain characteristics, such as a unidirectional radiation pattern, low profile, and stable reflection coefficient. Additionally, a radiator with low input impedance is applied for a wide gain bandwidth. The proposed antenna operates at 0.4~6.0 GHz and has a relatively low height and large gain bandwidth compared to the performance of previously studied antennas.

Compact and Robust Fabry-Perot Cavity Antenna with PEC Wall

In this paper, a novel Fabry-Perot cavity (FPC) antenna with a perfect electric conductor (PEC) wall is proposed to design a structurally compact and robust high-gain antenna. Generally, the FPC antenna comprising a PEC ground and a partially reflective dielectric surface (PRDS) is required to have a half-wavelength height to satisfy the resonance condition. If a perfect magnetic conductor (PMC) is substituted for the PEC ground, the height of the FPC antenna can be reduced to a quarter wavelength. The PRDS of the proposed FPC antenna is located on the PEC ground to obtain the effect of a PMC. Moreover, PEC walls are employed to block leakage by a guided mode inside the PRDS. As a result, the proposed FPC antenna can be designed as a compact high-gain antenna although it is composed of PEC ground and PRDS. To verify its feasibility, we simulated and measured the performance of the proposed antenna regarding the reflection coefficient, peak gain, and far-field radiation pattern. Finally, the height of the proposed antenna was reduced by approximately 50% compared with the conventional antenna, while the peak gain is more than equal to that of the conventional antenna.

Experimental Study of Microwave Attenuation in a Compartment Fire

In this letter, we show the experimental results of microwave attenuation characteristics for representative communication frequencies (UHF, public safety long-term evolution [PSLTE], LoRa, Wi-Fi, and LTE) in a compartment fire. We used kerosene, lumber, and urethane foam as fuels, which can be easily found in homes, and measured the signal intensity with three antenna heights to investigate the effect of the flame and smoke. In the compartment environment, the ionized particles were the dominant attenuation factor of the signals. Furthermore, measurements revealed that the attenuation depends on frequencies and fuel types. In particular, large attenuation was observed at particular frequencies when burning lumber and urethane foam.

Modeling and Designed of a Monopole Antenna that Operate at 3.3 [GHz] for Future 5G sub 6 [GHz

Antenna unit is an important part of ADAS L2, L2+ and Automated Driving L3 systems. It needs to function as needed in dGPS, HD Map Correction Services, OEM Radios and Navigation Systems. The presented monopole antenna model for 5G below 6 [GHz] operating at 3.3 [GHz] is developed. This work demonstrates the modeling, design, and determining of monopole antenna with intended targeted applications within the automotive system emerging autonomous vehicles space and as well as 5G Wireless Cellular Technology domain. FEKO simulation is undertaken rather than mathematical modeling to create the structure and conduct the analysis of the proposed monopole antenna. In order to support the fifth generation (5G) of wireless communication networks, SOS messages, vehicle tracking, remote vehicle start, Advanced Driver Assistance Systems (ADAS) L2, L2+/ Autonomous Driving (AD) L3 systems self-driving vehicles powered by 5G with rapidly growing sets of ADAS and AD features and functions within the autonomous space, USA cellular carriers mobile phone communication standard 4G MISO and 5G MIMO, LTE1, LTE2, connected functions, features/services, IoT, DSRC, V2X, and C-V2X applications and 5G enable vehicles destined for the NAFTA (USA, Canada and Mexico) market, a new single monopole antenna that operate at 3.3 [GHz] for future 5G (MIMO) below 6 [GHz] modeling, design and simulation with intended automotive applicability and applications is proposed. The presented novel new 5G below 6 [GHz] monopole antenna: 1. Is not being investigated on the literatures review and published papers studied. 2. No paper exists on these frequency bands. 3. The desired monopole antenna is a new antenna with fewer components, reduction in size, low profile, competitive cost, better response to received RF signals for frequencies for future 5G below 6 [GHz] with each of the following: a. Range of operating frequencies, 0.6 [GHz] to 5.9256 [GHz]. b. Center frequency = 3.2628 [GHz] ~ 3.3 [GHz] for the above band. c. Lambda (λ) = (3.0 x10^8 [m/sec^2]) / (3.3x10^9 [Hz]) = 0.090 [m] = 90 [mm], lambda (λ) /4 = (0.090 [m])/4 = 0.0225 [m] = 22.5 mm ~ 23 [mm], the overall monopole antenna height. To be more direct, simulation studies are carried out and are done utilizing FEKO software package from Altair to model the proposed monopole antenna for 5G below 6 [GHz] frequency band. The focus is on the frequency band for 5G sub 6 [GHz] cellular system. The paper will introduce the following key points: 1. Modelled and anayzed single element 5G sub 6 [GHz] monopole antenna. 2. Student version of CAD FEKO program was used to design our desired monopole antenna with a wire feed excitation coupled with step-by-step instructions is undertaken to highlight the model geometry creation of our monopole antenna. POST FEKO program is used to plot and view our simulation results. 3. We report the development of 5G below 6 [GHz] for fifth generation (5G) system that meets automotive and vehicle homologation specification requirement of antenna height < 70 [mm]. So that the proposed monopole antenna can easly be integrated into multi tuned cellular antenna system. 4. The FEKO simulation is conducted in 2D and 3D element model, in terms of Far-Field Vertical Gain as a function of an Elevation Angle plots. 5. Future research work and study for the next steps will be recommended.

Coverage Analysis and Scaling Laws in Ultra-Dense Networks

In this paper, we develop an innovative approach to quantitatively characterize the performance of ultra-dense wireless networks in a plethora of propagation environments. The proposed framework has the potential of simplifying the cumbersome procedure of analyzing the coverage probability and allowing the unification of single- and multi-antenna networks through compact analytical representations. By harnessing this key feature, we develop a novel statistical machinery to study the scaling laws of wireless networks densification considering general channel power distributions including small-scale fading and shadowing as well as associated beamforming and array gains due to the use of multiple antenna. We further formulate the relationship between network density, antenna height, antenna array seize and carrier frequency showing how the coverage probability can be maintained with ultra-densification. From a system design perspective, we show that, if multiple antenna base stations are deployed at higher frequencies, monotonically increasing the coverage probability by means of ultra-densification is possible, and this without lowering the antenna height. Simulation results substantiate performance trends leveraging network densification and antenna deployment and configuration against path loss models and signal-to-noise plus interference thresholds.

Authors' Response to "A Comment on 'Short Low- and Medium-Frequency Antenna Performance'" [Letter to the Editor

Some typing errors like in Figures 23 and 24 must be corrected from "n = 1" to "n = 4" according to the kind suggestion of our colleagues. Wave impedance does not deal with antenna performance, but instead with wave propagation. However, the calculations have been performed by means of software WIPL-D according to Figure 1 and for several antenna heights. These results are presented in Tables 1 and 2 along the x- and y-axes in numerical form. In this article, the theoretical transmitting top-loaded monopole antenna gain GT (dBi) corresponds to its directivity DT (dBi) according to Table 3 because it was calculated over perfect ground (no losses); in this case, at the frequency of f = 200 kHz. Traditionally, any analyzed transmitting monopole— its radiated waves reflected by perfect ground—are taken into account as produced by the antenna image underground. The image effect is increasing the antenna gain, effective antenna length, and antenna factor. Its transmitting equivalent area AeT can be calculated by the antenna numerical gain gT through the isotropic source effective area. Equations for these calculations are shown.

Underlay Radar-Massive MIMO Spectrum Sharing: Modeling Fundamentals and Performance Analysis

In this work, we study underlay radar-massive MIMO cellular coexistence in LoS/near-LoS channels, where both systems have 3D beamforming capabilities. Using mathematical tools from stochastic geometry, we derive an upper bound on the average interference power at the radar due to the 3D massive MIMO cellular downlink under the worst-case `cell-edge beamforming' conditions. To overcome the technical challenges imposed by asymmetric and arbitrarily large cells, we devise a novel construction in which each Poisson Voronoi (PV) cell is bounded by its circumcircle to bound the effect of the random cell shapes on average interference. Since this model is intractable for further analysis due to the correlation between adjacent PV cells' shapes and sizes, we propose a tractable nominal interference model, where we model each PV cell as a circular disk with an area equal to the average area of the typical cell. We quantify the gap in the average interference power between these two models and show that the upper bound is tight for realistic deployment parameters. We also compare them with a more practical but intractable MU-MIMO scheduling model to show that our worst-case interference models show the same trends and do not deviate significantly from realistic scheduler models. Under the nominal interference model, we characterize the interference distribution using the dominant interferer approximation by deriving the equi-interference contour expression when the typical receiver uses 3D beamforming. Finally, we use tractable expressions for the interference distribution to characterize radar's spatial probability of false alarm/detection in a quasi-static target tracking scenario. Our results reveal useful trends in the average interference as a function of the deployment parameters (BS density, exclusion zone radius, antenna height, transmit power of each BS, etc.).

Low-profile, wideband dual-polarized 1 × 2 MIMO antenna with FSS decoupling technique

AbstractA low-profile, wideband dual-polarized 1 × 2 multiple-input-multiple-output (MIMO) antenna with frequency selective surface (FSS) decoupling technique is presented. Low profile is realized with two different artificial magnetic conductor (AMC) cells out of which one operates at 3.5 GHz and other with dual band at 3.1 and 4.5 GHz. The proposed antenna height is maintained at 0.125λ0 which is significantly reduced when compared with the conventional perfect electric conductor (PEC) ground plane. Wideband dual polarization is enabled by two pairs of bow-tie antenna elements surrounded by a square ring placed in the orthogonal orientation. To mitigate the near-field coupling in 1 × 2 MIMO an FSS wall is constructed with wide band stop characteristics from 2.85 to 4.75 GHz. Measured results show by inserting FSS wall vertically, coupling reduction is improved by 27 dB over the existing coupling and the antenna exhibits a bandwidth of 57.14% (2.95–4.95 GHz) for VSWR<2 with port isolation of more than 25 dB for entire band of operation.

Design parameter analysis for ATSC 1.0 single frequency networks based on receiver multipath handling performance

This work proposes suitable network configurations for single frequency networks (SFNs) with ATSC 1.0 based on network coverage calculations and the laboratory multipath handling performance of commercial receivers. SFNs are widely used for delivering terrestrial digital television services because of their efficient use of the spectrum. In Mexico the analogue television transmissions switch-off occurred on 31 December 2016. Thus it is expected the adopted ATSC 1.0 system will be in force for the next several years despite the recent standardization of the ATSC 3.0 system. As ATSC 1.0 uses 8-VSB modulation the multipath handling capability of receivers is critical for the design of SFNs. The presented network planning results help develop technical normativity for implementing SFNs in Mexico and other countries that use ATSC 1.0. SFNs with transmitter separation up to 130 km are fully covered for outdoor reception mainly due to the directivity of the receiving antenna. Moreover for indoor reception at least 70% of an SFN coverage area can be achieved with a transmitter separation of up to 60 km depending on the radiated power and the transmitter antenna height.

Additively manufactured high gain cavity backed Ku-band slot antenna

Cavity backed slot antenna covering entire Ku-band satellite communications frequency band (10.5–14.5 GHz) is designed and manufactured using both 3D printing and traditional metal milling for performance comparison. Four cavity backed radiating slots are fed with a waveguide aperture and a stub along the aperture magnetic field is placed to improve the antenna gain and to reduce the mutual coupling among the slots. Measured fractional bandwidth is 38% for both antennas. Measured gain in the target bandwidth is up to 13.1 dBi and 13.5 dBi for 3D-printed and all-metallic variant, respectively. Average HPBW in E-plane is 34° throughout the band. Antenna height is only 0.78λ at the center frequency including the stub and the feed waveguide, and its transverse dimensions are 1.51λ by 1.82λ. Wideband, high-gain, light weight, and small form factor features of the proposed antenna can be used in array form for satellite and radiolink communications.

Signal Stability and the Height-Correction Method for Ground-Penetrating Radar In Situ Asphalt Concrete Density Prediction

Ground-penetrating radar (GPR) has shown great potential for asphalt concrete density prediction used in quality control and quality assurance. One challenge of continuous GPR measurements is that the measured dielectric constant could be affected by signal stability and antenna height. This would jeopardize the accuracy of the asphalt concrete density prediction along the pavement. In this study, signal instability and shifting antenna height during continuous real-time GPR measurements were identified as main sources of error. After using a bandpass filter to preprocess the signal, a least-square adaptive filter, using gradient descent and least mean square methods, was developed to reconstruct the received signal to improve its stability. In addition, simulations were performed to evaluate the impact of geometric spreading caused by shifting antenna height during testing. A height correction was developed using a power model to correct the height-change impact. The proposed filter and height-correction method were assessed using static and dynamic tests. The least-square adaptive filter improved signal stability by 50% and the height-correction method removed the effect of shifting antenna height almost entirely.

The Influence of Antenna Height on the Measurement of Collective Variables Using an Ultra-Wide Band Based Local Positioning System in Team Sports.

Ultra-wide band (UWB) based local positioning systems (LPS) are based on devices and a portable antenna set. The optimal installation height of the antennae is crucial to ensure data accuracy. Collective variables are metrics that consider at least two pairs of coordinates, which may lead to lower precision than an individual one. Therefore, the aim of this study was to compare the influence of antenna height with collective metrics using a UWB (i.e., IMU; WIMU PRO™, RealTrack Systems, Almeria, Spain) based LPS. Data acquisition was carried out in a basketball court measuring 28 × 15 m. Five devices were used; one of which was carried by a healthy and well-trained athlete (age: 38 years, mass: 76.34 kg, height 1.70 m), while each of the remaining four was positioned on a tripod in one of the four corners of the court. Four kinds of variables were extracted: (1) static distances, (2) dynamic distances, (3) static areas and (4) dynamic areas in all antenna installation modes of 0.15, 1.30 and 2.00 m. The results showed that the antenna of 1.30 m provided better accuracy for all measures (% difference range from −0.94 to 1.17%) followed by the antenna of 2.00 m (% difference range from −2.50 to 2.15%), with the antenna of 0.15 m providing the worst accuracy level (% difference range from −1.05 to 3.28%). Overall, the measurements of distance metrics showed greater accuracy than area metrics (distance % difference range from −0.85 to 2.81% and area % difference range from −2.50 to 3.28). In conclusion, the height of the antennae in basketball courts should be similar to the height at which the devices are attached to a player’s upper back. However, as the precision is sensitive to the magnitude of the measure, further studies should assess the effects of the relative height of antennae in team sports with greater playing spaces.

전방향성 방사 패턴을 갖는 차량용 HF 대역 저자세 안테나

This paper proposes a high-frequency (HF) band on an extremely low-profile antenna that can be mounted on the roof of a car. This antenna generates a monopole-like omnidirectional radiation pattern despite the low height of the patch shape (5 cm, 0.0034λ @ 20 MHz). A coil was installed at the edge of the antenna feeding part and the patch to increase the quality factor (Q-factor) and a shorting pin was connected next to the coil to ensure that in-phase current flows through the feeding part and shorting pin. The coil is designed such that the quality coefficient reaches 1,000 considering the mutual inductance and internal resistance. The Q-factor of the antenna is increased by changing the shorting pin to a shorting plate. A quarter-wavelength monopole antenna with a target frequency of 20 MHz is 6 m in length, whereas the proposed antenna height is only 5 cm (0.0034λ @ 20 MHz) and the patch size is 70 cm × 70 cm (0.047 λ×0.047 λ @ 20 MHz), making it easy to install the antenna on the vehicle roof. The gain in the Q-factor of the antenna, calculated using a 3D radio wave simulation software, was −9 dBi, and the gain when it was mounted on the vehicle roof was −2.7 dBi. The power value measured by introducing the antenna showed a star similar to the gain value calculated via simulations.

High-Resolution Image Transmission from UAV to Ground Station for Search and Rescue Missions Planning

Search and rescue (SAR) missions comprise search for, and provision of aid to people who are in distress or imminent danger. Providing the best possible input for the planners and search teams, up-to-date information about the terrain is of essential importance because every additional hour needed to search a person decreases probability of success. Therefore, availability of aerial images and updated terrain maps as a basis for planning and monitoring SAR missions in real-time is very important for rescuers. In this paper, we present a system for transmission of high-resolution images from an unmanned aerial vehicle (UAV) to the ground station (GS). We define and calculate data rate and transmission distance requirements between the UAV and GS in a mission scenario. Five tests were designed and carried out to confirm the viability of the proposed system architecture and modules. Test results present throughput measurements for various UAV and GS distances, antenna heights and UAV antenna yaw angles. Experimental results from the series of conducted outdoor tests show that the proposed solution using two pMDDL2450 datalinks at 2.4 GHz and a directional antenna on the receiving side can be used for a real-time transmission of high-resolution images acquired with a camera on a UAV. Achieved throughput at a UAV-GS distance of 5 km was 1.4 MB/s (11.2 Mbps). The limitations and possible improvements of the proposed system as well as future work are also discussed.

A tapered CPW fed leaky‐wave antenna based on substrate integrated waveguide with reduced side‐lobe level

A novel method for confining the undesired radiation of the feed transition of a low-profile leaky-wave antenna (LWA) is demonstrated in this paper. The proposed design method uses novel tapered CPW transitions resulting in variation of the parasitic capacitance and electrical length of the feed. This leads to the reduction of the side-lobe level (SLL), which is dictated by the feed and the slotted sections of the antenna. The undesired radiation from the feed becomes crucial in the low-profile antenna in which the surface-mounted connector along feed transition is the only practical feeding mechanism. The key novelty of the proposed approach is the reduction of SLL by exclusively modifying the feed structure rather than the slotted radiation section. To validate the proposed approach, a modified compact feeding mechanism for LWA is designed. The antenna is realized based on the substrate integrated waveguide (SIW). The antenna's length, width, and height are 110 mm, 31 mm, and 0.5 mm, respectively. The operating frequency band was chosen as 26 to 30 GHz, covering an allocated 5G band. The measured peak realized gain and SLL are 6.1 dBi and − 11.4 dB, respectively. An improvement of 5.7 dB in SLL compared to the conventional LWA was observed. The simple fabrication process and efficiency of the proposed method make it a viable approach for reducing the SLL of the low-profile antennas. Compactness, low SLL, and proper gain of the reported antenna make it a suitable candidate for 5G vehicle to everything (V2X) communications and mm-wave navigation systems.

Designing GNSS HUMGAdj software package for surveying and mapping

GNSS technology has made great contributions to the development of surveying and mapping in Vietnam. Many useful GNSS processing software packages have been created and widely used all over the world. However, since these software programs only have input and output, the new users without expert theoretical knowledge (especially new students) can not understand the principle or interfere with the process to obtain explicit results at each step. Therefore, the research team has built the GNSS-HUMGAdj software package to visually illustrate GNSS data processing steps for students to use. In the design stage, the group has learnt the experience in programming GNSS processing software, inheriting published GNSS data processing algorithms. In addition, some algorithms such as converted GNSS baseline in resolving the relative positioning problem, adjusting the receiver antenna height, and the effect caused by the change of distance over time were developed in the software.