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Several studies have examined the propagation losses of the Human Body Communication (HBC) channel. However, a general agreement has not be found yet. In this paper, the complete S-matrix of the HBC channel is measured on an human subject using two kinds of electrode devices. The data is integrated in a lumped element model, which allows to take into account for the capacitive return path of realistic...
This paper presents a low cost OFDM based channel sounding technique which can be implemented on a low power embedded system. The technique is first used to measure the channel of an indoor environment and is validated by comparison with a VNA and a ray-tracing simulator. We then show its usage in two interesting situations. Finally, we conclude the paper by giving the advantages and drawbacks of...
Near Vertical Incidence Skywave communication solutions are known to be reliable and quickly deployable, but modeling a suitable radio link requires a good prediction of the ionosphere behavior and insights regarding ionospheric propagation. Within the framework of the national PN-II SIRIUS project, the Technical University of Cluj-Napoca has acquired, installed, and employed the NovAtel GPStation-6...
This paper presents propagation modelling of different on-body and off-body wireless communication scenarios for dairy cows in barns at 2.4 GHz. Based on the obtained propagation models, a WBAN that monitors multiple heath parameters is designed for optimal performances in terms of energy efficiency and packet error rate.
In this paper, a test bed for LTE-Advance Beamforming is proposed. The test bed is composed of an 8×1 monopole antenna array matched at the mid and higher bands for LTE operating in Europe, wide band transceivers with agile architectures provided by Analog Devices, and mid range FPGA from Xilinx for antenna weight calculation and beamforming on the fly. The test bed is promising to give a useful mean...
Universidad Politécnica de Madrid (UPM) is participating in the Alphasat propagation experiment by measuring the copolar level of the Q-Band beacon at 39.4 GHz since April 2014. In this paper the results of the first two complete years of measurements (until March 2016) are presented with regards to excess and total attenuation. The reference level is calculated on an event-by-event basis in the first...
This paper presents a measurement-based analysis of both the specular- and dense multipath components (SMC and DMC) at 94 GHz in an indoor environment. A total of 15 positions were measured with a virtual antenna array system, from which we have calculated Power Delay Profiles (PDP). A method was developed that allowed for the full-polarimetric estimation of the specular propagation paths, after which...
A broadband channel sounder measurement campaign was conducted to investigate the ship-to-ship propagation channel in the C-band at 5.2 GHz with a signal of 120 MHz bandwidth. This paper presents details of the measurement campaign. Two scenarios with two vessels in rough sea conditions that either follow or drive towards each other are presented. First results in terms of power delay profile and...
The paper gives a description of the satellite propagation measurement site established in Ljubljana. It consists of two beacon receivers, measuring the Alphasat and Astra 3B beacons at Ka-band and at Q-band, and of a co-located rain gauge. Statistical analysis of collected measurements is performed to create complementary cumulative distribution functions of excess attenuation and rain rate. First...
This contribution is based on an novel imaging system able to create real time radar images for personnel security screening recently presented. The imaging is performed as the person being screened continuously moves across a corridor populated with transmitters and receivers, and taking advantage of the person's movement to increase the number of observation angles. As part of a preliminary study...
This paper explores the effect of increasing number of receivers to evaluate the geographic location of the High Frequency (HF) transmitters for distances in the radius of 2000 km. In the case of HF propagation over long distances, signals propagate using skywaves and are reflected back to the earth from the ionosphere. The Quasi-Parabolic (QP) model of the ionosphere provides analytic equations for...
The maximum ratio combined total isotropic sensitivity (TIS) of high order MIMO system in a real phone prototype is presented in this paper. The value of combined TIS is estimated through antenna pattern combination and verified by experiments. The impact from the order of MIMO system, the propagation model and the user body effect are investigated.
We present two configurations of multiport antennas for Multiple-input Multiple-output (MIMO) application. The configurations are comprised of three and four dual-polarized self-grounded bowtie antenna as the element, respectively. The MIMO performance of both antennas is evaluated in Random Line-of-Sight (Random-LOS) and Rich Isotropic Multipath (RIMP) channel models as two edge propagation environments...
THz impulse communications is a new system concept based on an imaging radar that we have been developing for biomedical imaging applications the past ten years. Its hybrid architecture combines the high-peak-power and spread-spectrum of photoconductive-switch transmitters with the high-responsivity and broad-bandwidth (RF and video) of Schottky-rectifier receivers. The data is impressed by simple...
This paper investigates reactance compensation method to eliminate the impact of cross-coupling in single frequency inductive power transfer (IPT) system with arbitrary number of receivers. Receiver-side resonance loses its optimality in multiple receiver scenarios under the existence of significant cross-coupling among receivers. Therefore, the resonant capacitances are added with compensatory reactances,...
Considering the imminent migration of services to the Ka- and Q-bands, a payload dedicated to propagation measurements in these bands has become available from the Alphasat satellite under the coordination of the European Space Agency. This has strongly motivated the formation of many measurement campaigns across Europe in an effort to enhance the scientific databases with new, more reliable propagation...
Ray tracing simulations are used to investigate the RF fingerprinting in open areas over irregular terrain profiles. We show that these simulations can project the RF signature exclusiveness of an emitter location in space by means of received power, mean azimuth DoA and delay spread heat maps. Additionally, full-3D ray-tracing simulations allow us to investigate the amount of energy inside and outside...
Phased Array Feed (PAF) systems are installed on the Westerbork dishes, enabling new science for the astronomical community. Twelve dishes are equipped with PAF system hardware, and the central processing systems are in place too. The PAFs need a dedicated calibration scheme in order to satisfy stability requirements. The verification process has finished for most system elements, and the first validation...
The Alphasat telecommunication satellite was launched in July, 2013 and beside of the main payload it carries four scientific experiments. One of them is the Aldo Paraboni Scientific Experiment, a propagation experiment in the Ka and Q radio bands. The experiment is coordinated by the European Space Agency under the framework of ARTES 8 Telecom program. Hungary, similarly to other European experimenters...
A volume pixel subspace-based optimization method (SOM) is proposed to solve the electromagnetic imaging of the wave impenetrable objects/perfect electric conductor (PEC). In this proposed method, the PEC objects are approximated by highly lossy dielectric scatterers with pure imaginary permittivity and thus volume pixel SOM is successfully employed. There is no prior information such as the number...
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