Antenna Calibration Methods for Antenna Factor Measurements

2012 ◽  
Vol 2 (4) ◽  
pp. 43-59 ◽  
Author(s):  
L. Mescia ◽  
O. Losito ◽  
V. Castrovilla ◽  
P. Bia ◽  
F. Prudenzano
Keyword(s):  
Electromagnetic Interference ◽  
Electromagnetic Compatibility ◽  
Ground Plane ◽  
Empty Space ◽  
Horn Antenna ◽  
International Standards ◽  
Impedance Method ◽  
Calibration Methods ◽  
Antenna Impedance ◽  
Antenna Factor

In the fields of electromagnetic interference and electromagnetic compatibility, it is important to measure the strength of the electric field originating from electric devices. For this purpose, knowledge of the antenna factor of a receiving antenna is necessary. According to international standards, the accurate measurement of the antenna factor involves the use of calibration test sites characterized by very large sizes of both the ground plane and the empty space volume above it. As a consequence, these setup conditions make the antenna factor measurements quite expensive for the customer. In this paper, the authors discuss the well know antenna-based and site-based methods as well as recently measurement method called Antenna Impedance Method as able to obtain the free-space antenna factor. Moreover, the authors investigate on the suitability of semi-anechoic chamber for reliable antenna factor calibrations. In particular, the experimental measurements of the antenna factor obtained by using the antenna impedance method were compared with Standard Field Method and the data provided by the manufacturer of three antennas (Biconical, Log-periodic and Horn antenna) founding an agreement with the international standard ANSI C63.5-2006.

scholarly journals Conducted Emi Model for Flyback PFC Converter

2019 ◽  
Vol 8 (3) ◽  
pp. 6916-6923
Keyword(s):  
Power Factor ◽  
Electromagnetic Interference ◽  
Electromagnetic Compatibility ◽  
Input Power ◽  
International Standards ◽  
Noise Sources ◽  
Flyback Converter ◽  
Full Compliance ◽  
Switched Mode Power Supply ◽  
Conducted Emi

Power Factor Correction (PFC) units are used at the front end of Switched Mode Power Supply (SMPS) to improve the input power factor. However, they generate Electromagnetic Interference (EMI) which needs to be mitigated to compliant levels prescribed by International Standards. The Electromagnetic Compatibility (EMC) standards have set regulations which require expensive instruments and environment for their measurement. Hence there is a need for predicting Conducted EMI by simulation before the product is tested for full compliance to reduce the complexity of the circuit design and cost. To estimate the Conducted EMI, it is important to identify the main noise sources and their conduction paths. This can be achieved by simulating the circuit using the exact models of the transformer, capacitor, PCB trace, and the switching semiconductors. In this paper these components of PFC flyback converter are modelled using SPICE models, datasheet defined component parameters and experimental measurements. The theoretical analysis and simulation results show that the method discussed can predict and analyse the Conducted EMI. This is tested experimentally on a Flyback PFC converter working in Critical Conduction Mode. A line filter is designed and used to bring the noise to compliant levels. Simulation and Experimental results after using the line filter are also presented.

Issue on Calibration of Direct Feed Biconical Antenna in a Semi-Anechoic Chamber Using Standard Antenna Method

2014 ◽  
Vol 903 ◽  
pp. 273-278 ◽  
Author(s):  
Syarfa' Zahirah Sapuan ◽  
Mohd Zarar Mohd Jenu ◽  
Alireza Kazemipour
Keyword(s):  
Electromagnetic Compatibility ◽  
Ground Plane ◽  
Anechoic Chamber ◽  
Space Environment ◽  
Frequency Range ◽  
Biconical Antenna ◽  
Measurement Results ◽  
Antenna Type ◽  
Antenna Factor ◽  
Antenna Calibration

Antenna calibration is crucial to ensure the accuracy of Electromagnetic Compatibility (EMC) measurement results. Standard Antenna Method (SAM) is one of the methods widely used in antenna calibration which requires reference antenna with known Antenna Factor (AF) in a free space environment. The work presented in this paper is on the calibration of the AF of a direct-feed biconical antenna in a semi-anechoic chamber (SAC) with considerations given to the effects of ground plane, antenna height, reference antenna type and effects of phase center. The frequency range for the analysis is from 200 MHz to 2 GHz. It is found that antenna located 1.5 m from ground provides the best result compared to modeling. In addition, the phase centers of the reference and test antenna must be at the same positions during the measurements.

scholarly journals Influence of Aircraft Power Electronics Processing on Backup VHF Radio Systems

Electronics ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 777
Author(s):  
Jan Leuchter ◽  
Radim Bloudicek ◽  
Jan Boril ◽  
Josef Bajer ◽  
Erik Blasch
Keyword(s):  
Power Electronics ◽  
Electromagnetic Interference ◽  
Communication Systems ◽  
Electromagnetic Compatibility ◽  
Intermediate Frequency ◽  
Radio Communication ◽  
Very High Frequency ◽  
Switching Power ◽  
Radio Systems ◽  
The Impact

The paper describes the influence of power electronics, energy processing, and emergency radio systems (ERS) immunity testing on onboard aircraft equipment and ground stations providing air traffic services. The implementation of next-generation power electronics introduces potential hazards for the safety and reliability of aircraft systems, especially the interferences from power electronics with high-power processing. The paper focuses on clearly identifying, experimentally verifying, and quantifiably measuring the effects of power electronics processing using switching modes versus the electromagnetic compatibility (EMC) of emergency radio systems with electromagnetic interference (EMI). EMI can be very critical when switching power radios utilize backup receivers, which are used as aircraft backup systems or airport last-resort systems. The switching power electronics process produces interfering electromagnetic energy to create problems with onboard aircraft radios or instrument landing system (ILS) avionics services. Analyses demonstrate significant threats and risks resulting from interferences between radio and power electronics in airborne systems. Results demonstrate the impact of interferences on intermediate-frequency processing, namely, for very high frequency (VHF) radios. The paper also describes the methodology of testing radio immunity against both weak and strong signals in accordance with recent aviation standards and guidance for military radio communication systems in the VHF band.

scholarly journals Reduction of Electromagnetic Interference Using ZnO-PCL Nanocomposites at Microwave Frequency

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Abubakar Yakubu ◽  
Zulkifly Abbas ◽  
Nor Azowa Ibrahim ◽  
Ahmad Fahad
Keyword(s):  
Electromagnetic Interference ◽  
Electromagnetic Compatibility ◽  
Environmentally Friendly ◽  
Microwave Frequency ◽  
Absorption Properties ◽  
Radio Emissions ◽  
Surface Areas ◽  
Home Appliance ◽  
Coaxial Probe ◽  
Very High

In industrial equipment and home appliance applications, the electromagnetic compatibility compliance directive (ECCD) demands that electromagnetic interference side effects be eliminated or marginally minimized. The equipment must not disturb radio and telecommunication as well as other appliances. Additionally the ECCD also governs the immunity of such equipment to interference and seeks to ensure that this equipment is not disturbed by radio emissions when used as intended. Many types of absorbing materials are commercially available. However, many are expensive and not environmentally friendly. It is in the light of the above that we studied the electromagnetic absorption properties of ZnO-PCL nanocomposites prepared from cheap and abundant resources which are environmentally friendly (zinc and polycaprolactone). The test was carried out using a microstrip, open ended coaxial probe, and vector network analyzer. Amongst other findings, result showed that the ZnO-PCL nanocomposite has the capability of attenuating microwave frequency up to −18.2 dB due to their very high specific surface areas attributed to the nanofillers at 12 GHz.

Predicting Electromagnetic Interference to a Terminated Wire Using Characteristic Mode Analysis

2021 ◽  
Vol 35 (11) ◽  
pp. 1318-1319
Author(s):  
Mohamed Hamdalla ◽  
Anthony Caruso ◽  
Ahmed Hassan
Keyword(s):  
Electromagnetic Interference ◽  
Incident Angle ◽  
Electromagnetic Coupling ◽  
Ground Plane ◽  
Mode Analysis ◽  
Characteristic Mode ◽  
Work Characteristic

Electromagnetic coupling to realistic wire configurations exhibit large variations with respect to the frequency, incident angle, and polarization of the interfering signal. In this work, Characteristic Mode Analysis (CMA) is used to calculate the fundamental modes of a terminated wire above an infinite ground plane. Using the properties of the modes, the coupled currents to the wire’s loads are predicted for different incident excitations. Using this simple but practical wire configuration, we show the versatility of CMA in practical electromagnetic interference and coupling applications.

scholarly journals Обеспечение электромагнитной совместимости систем интеллектуального управления при появлении помех в судовых кабельных трассах

2020 ◽  
Author(s):  
A.M. Agafonov ◽  
A.A. Worshevsky ◽  
P.A. Vorshevskii ◽  
E.S. Grishakov ◽  
A.S. Kornev
Keyword(s):  
Electromagnetic Interference ◽  
Electromagnetic Compatibility ◽  
Mutual Influence ◽  
Electromagnetic Coupling ◽  
Systems Design ◽  
Power Input ◽  
Travelling Wave ◽  
Normal Function ◽  
Input Output ◽  
Digital Technique

Системы интеллектуального управления базируются на использовании цифровой техники и по своему принципу действия восприимчивы к внешним помехам. Изменения напряжения и тока в кабелях, электромагнитные поля могут привести к появлению в цепях передачи информации и питания систем напряжений, похожих на полезные сигналы, что приведет к сбоям в работе систем. Технология электромагнитной совместимости (ЭМС) призвана устранить взаимные влияния оборудования и обеспечить его нормальную работу в условиях действия помех. Кабельные трассы являются особенно значимым фактором для обеспечения ЭМС на судах. Помехи распространяются в кабелям от источников к чувствительному электронному оборудованию (ЭО). Метод распространяющихся волн дает возможность рассчитать изменения помех при распространении по кабелям. Силовые и информационные кабели могут прокладываться в одной трассе, что приводит к их электромагнитной связи. Рассмотренные модели оценивают наведенные напряжения в информационных кабелях при появлении помех в силовых кабелях. Параметры электромагнитной связи кабелей могут быть определены расчетным путем и экспериментально на основе предлагаемой методики. Приведенные рекомендации по снижение уровня излучаемых помех от кабельных трасс, снижению наведенных напряжений и выполнению экранирования призваны помочь разработчикам ЭО и систем в обеспечении ЭМС.Intellectual control systems are based on digital technique. Digital electronic equipment (EE) is the receptor of electromagnetic interference due to its function principle. EE malfunction can be caused by induced voltages in input/output and power supply circuits. Voltage and current changes in cables leads to electromagnetic noise and induced voltages. Protection technique for power, input/output, case and grounding ports can be used in equipment and ship systems design. Electromagnetic compatibility technique must eliminate mutual influence of EE and give normal function of EE in real electromagnetic environment. Cable run is important factor for EMC obtaining in ships. Noise voltage propagates in cable from noise source to sensitive EE. Voltage parameters can be calculated with travelling wave technique. There are power and information cables in shipboard cable run. Electromagnetic coupling of cables leads to voltages in one cable induced by voltages and current in other cable. Coupling models give possibility to calculate induced voltages. Parameters of coupling can be determined with calculation on the base of detailed information about cable run or with proposed experiment procedure. Proposed recommendations about cable emission decreasing, cables decoupling and shielding can be useful for EMC obtaining.

scholarly journals X-band compact dual circularly polarized isoflux antenna for nanosatellite applications

2017 ◽  
Vol 9 (7) ◽  
pp. 1509-1516 ◽  
Author(s):  
Eric Arnaud ◽  
Cyrille Menudier ◽  
Jamil Fouany ◽  
Thierry Monediere ◽  
Marc Thevenot
Keyword(s):  
Circular Polarization ◽  
Microstrip Line ◽  
Ground Plane ◽  
Axial Ratio ◽  
Horn Antenna ◽  
Azimuth Angle ◽  
Original Solution ◽  
Circularly Polarized ◽  
X Band

This paper presents an original solution to design a compact dual circularly polarized isoflux antenna for nanosatellite applications. This kind of antenna has been previously designed in our laboratory, for a single circular polarization. This antenna is composed of a dual circularly polarized feed and a choke horn antenna. This feed is a cross-shaped slot in the ground plane, which provides coupling between a patch and a ring microstrip line with two ports. It is located at the center of a choke horn antenna. The simulated antenna presents an axial ratio <3 dB and a realized gain close to 0 dB over a 400 MHz bandwidth (8.0–8.4 GHz) at the limit of coverage, i.e. 65° whatever the azimuth angle (φ) and the port. A 20 dB matching for each port and 13 dB isolation characteristics between the two ports have been achieved on this bandwidth. It has been realized and successfully measured.

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