Spectral Analysis of Electromagnetic Compatibility

The report's main aim was to transmit the frequency signals without any disturbances and compute the time and frequencies of energies. Conduct the data burst system with the help of an anechoic chamber to study the electromagnetic interference and utilise the spectrum analyser to identify the required frequency during the conduction of signal transmission and minimise the noise disturbances.

A Novel 3D PILA-Type UHF RFID Tag Antenna Mountable on Metallic Objects for IoT Indoor Localization

In this paper, a novel 3D planar inverted-L antenna (PILA) Ultrahigh Frequency (UHF) Radio Frequency Identification (RFID) tag mountable on metallic surfaces is proposed for the Internet of Things (IoT) indoor localization applications. The proposed tag antenna (45 mm × 82 mm × 4 mm or 0.137λ × 0.25λ × 0.012λ) is designed for mounting on metallic objects. The 3D PILA antenna is fabricated using a copper sheet of thickness 1 mm and air as the dielectric substrate in order to minimize costs for materials and realization. In the design, T-slot has been inserted in the radiating element for tuning of the tag’s resonance for achieving good matching with the chip. Also, a simple equivalent circuit model has been obtained to analyze the impedance of the 3D PILA. Based on the optimized design, the fabricated prototype has been measured in the anechoic chamber. The resonant frequency of the proposed tag is stable, and it is not affected much by the metallic object. The measurement results of the antenna prototype demonstrated a reasonable agreement with the simulation results, and a read range of 3.6 m was measured inside an anechoic chamber. Most importantly, in the building hallway, the proposed tag is able to achieve a maximum read distance of 18 m with a transmitted power of 31.5 dBm at 867 MHz when placed on metal. With the 3D PILA antenna structure, the proposed antimetal tag is a suitable solution that can be integrated into an indoor localization scenario.

A novel methodology for time-domain characterization of a full anechoic chamber for antennas measurements and exposure evaluation

<p>In this paper we present a novel methodology for time-domain characterization of a full anechoic chamber using the finite integral method. This approach is considered fast, accurate and not intensive for computer resources. The validation of this approach is carried out on CST-microwave studio for a full anechoic chamber intended for antennas measurement applications and electromagnetic exposure evaluation for cellular network. Low, medium and high gain sources are used in this study. The simulations are realized on a personal computer of medium performances (i7 CPU and 16 GB of RAM). The stability and the convergence of our approach are obtained thanks to local mesh and auto-regressive linear filtering techniques. The minimization of the simulation time is based on use of the Huygens sources in the place of the antennas. The maximum error of the chamber as well as the wave depolarization into the chamber are at one with the previous work and the catalogs of the principles chambers manufacturers for the proposed tests in this paper. The Full simulations time is about 15 hours in average.</p>

Perception of noise from small quadcopter UAVs

This paper presents the results of a study evaluating the human perception of the noise produced by small quadcopter UAVs. The study utilised recordings of the noise produced by several different quadcopter UAVs in hover and in constant-speed flight at a fixed altitude. These recordings were made using an eigenmic system. The recordings were reproduced using a 3D sound reproduction system located in the large anechoic chamber at the University of Auckland. Human subjects were asked to rate the annoyance of the recordings. The responses of the test subjects are presented and these are compared with objective metrics to assess suitable metrics for quantifying the impact of noise from these vehicles on humans.

Loudspeaker-based sound reproduction for evaluating noise transmission into the car cabin

Virtual and laboratory-based design techniques can accelerate the development process over conventional prototype-and-field-test procedures. In car acoustics, the transmission of outside airborne noise into the cabin needs to be understood and managed. Here, we evaluate the accuracy of sound field recording and reproduction techniques for investigating the transmission of airborne noise into the driver's cabin of a car. Reference measurements of a real sound field, generated by a truck with idling engine to create a realistic scenario, were carried out in a semi-anechoic chamber. The reference sound field was recorded inside and around a test car. Additionally, a spatial recording of the reference sound field was carried out and used to reproduce the reference sound field over a loudspeaker array in a different, fully anechoic chamber, where the sound field was again measured inside and around the same test car. A comparison of the measured loudness inside the test car shows that this key parameter for sound quality could be reproduced rather faithfully over a loudspeaker array in a controlled testing facility.