scholarly journals Traceable calibration of a horizontally polarised reference antenna with omnidirectional pattern at VHF frequencies for ILS field strength validation

2013 ◽  
Vol 11 ◽  
pp. 7-14
Author(s):  
T. Schrader ◽  
T. Kleine-Ostmann ◽  
J. Bredemeyer
Keyword(s):  
Field Strength ◽  
Uncertainty Budget ◽  
Antenna Gain ◽  
Practical Application ◽  
Scattering Parameters ◽  
Frequency Range ◽  
Antenna Factor ◽  
Calibration Setup ◽  
Validation Tool ◽  
Traceable Calibration

Abstract. We present a traceable calibration of a specially designed horizontally polarised reference antenna with an omnidirectional pattern in the E-plane for the frequency range between 105 MHz and 120 MHz. This antenna is used as a validation tool for absolute field strength measurements at the localizer transmitter of an instrument landing system (ILS) at airports and is carried by a helicopter. We investigate whether we can treat it as a dipole-like antenna in the calibration setup despite its disk-shape body. We also investigate the suitability of an anechoic chamber for antenna calibration though it was not designed for that purpose. The measurements are based on scattering parameters (S-parameters) which we apply in the 3-antenna-method (TAM or 3-AM) to obtain the antenna gain and the antenna factor, respectively. An uncertainty budget for the antenna gain calibration is derived. We also report on the first practical application of the calibrated reference antenna.

scholarly journals Characteristics, calibration and measurement uncertainty of RF field strength meters in the frequency range up to 18 GHz

2007 ◽  
Vol 5 ◽  
pp. 435-438 ◽  
Author(s):  
R. Pape ◽  
K. Münter ◽  
T. Schrader
Keyword(s):  
Field Strength ◽  
Measurement Uncertainty ◽  
Electromagnetic Fields ◽  
Measurement Data ◽  
Uncertainty Budget ◽  
Field Structure ◽  
Frequency Range ◽  
Field Representation ◽  
Radiation Monitors

Abstract. Due to their construction, the devices used for the measurement of electromagnetic fields (radiation monitors) must be calibrated individually. The measurement data obtained are documented in a calibration certificate and the user must take them into account in the uncertainty budget he has to draw up. In addition to the uncertainty contributions of the field representation and of the transfer, other contributions occur which depend on the special constructive features of these devices. When the uncertainty budget is drawn up, it depends on the application and the information about the field structure which contributions will have an effect and which will not. The procedure will be explained by an example.

scholarly journals Simulation of microstrip radio altimeter antenna for aircraft

Doklady BGUIR ◽  
2021 ◽  
Vol 19 (5) ◽  
pp. 5-12
Author(s):  
A. V. Gusinski ◽  
M. S. Svirid ◽  
D. A. Kondrashov ◽  
A. A. Kopshai ◽  
D. G. Bulavko ◽  
...  
Keyword(s):  
Microstrip Antenna ◽  
Vertical Plane ◽  
Dielectric Substrate ◽  
Side Lobe ◽  
Antenna Gain ◽  
Practical Application ◽  
Frequency Range ◽  
Electrical Parameters ◽  
Receiving Antenna ◽  
Domestic Ceramic

The purpose of the article is to carry out mathematical modeling of the main characteristics and parameters of a microstrip antenna, the dielectric substrate of which is created from a domestic ceramic sample and to substantiate the use of a microstrip antenna as a transmitting and receiving antenna in a radio altimeter. It is shown that a microstrip antenna on a ceramic material substrate with a relative permittivity ε = 9.6 and a thickness of 0.2 mm has good electrical parameters in the frequency range of 31.5–33.5 GHz. Including the width of the antenna radiation pattern at the level of –3 dB is 12.5 degrees in the horizontal plane and 26.7 degrees in the vertical plane. In this case, the antenna gain is 17 dB and the level of the first side lobe is –20 dB relative to the main antenna lobe. Also the practical application of microstrip array antennas inphase as a transmitting and receiving antenna for a radio altimeter installed on aircraft is described in the article. The range of the altimeter reaches 300 m.

scholarly journals Results of an intercomparison for free space antenna factor measurements within the German Calibration Service (DKD)

2016 ◽  
Vol 14 ◽  
pp. 11-16
Author(s):  
Thomas Kleine-Ostmann ◽  
Frank Huncke ◽  
Dieter Schwarzbeck ◽  
Otto Martetschläger ◽  
Jürgen Gaßner ◽  
...  
Keyword(s):  
Free Space ◽  
Frequency Range ◽  
Space Antenna ◽  
Different Types ◽  
Antenna Factor

Abstract. In this paper we discuss the results of an intercomparison for free space antenna factor measurements performed within the German Calibration Service (DKD). Three different types of antennas covering the frequency range from 30 MHz to 26.5 GHz have been calibrated in five different laboratories using different methods and calibration sites to obtain the free space antenna factor. The results agree well within the uncertainties specified by the laboratories suggesting that different approaches and different measurement sites to obtain the free space antenna factor are well compatible.

scholarly journals Detection and estimating the blood accumulation volume of brain hemorrhage in a human anatomical skull using a RF single coil

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e10416
Author(s):  
Moshe Oziel ◽  
Boris Rubinsky ◽  
Rafi Korenstein
Keyword(s):  
Experimental Study ◽  
Electromagnetic Radiation ◽  
Hemorrhagic Stroke ◽  
Average Error ◽  
Tissue Fluid ◽  
Brain Hemorrhage ◽  
Scattering Parameters ◽  
Frequency Range ◽  
Single Coil ◽  
Chicken Blood

Objective An experimental study for testing a simple robust algorithm on data derived from an electromagnetic radiation device that can detect small changes in the tissue/fluid ratio in a realistic head configuration. Methods Changes in the scattering parameters (S21) of an inductive coil resulting from injections of chicken blood in the 0–18 ml range into calf brain tissue in a human anatomical skull were measured over a 100–1,000 MHz frequency range. Results An algorithm that combines amplitude and phase results was found to detect changes in the tissue/fluid ratio with 90% accuracy. An algorithm that estimated the injected blood volume was found to have a 1–4 ml average error. This demonstrates the possibility of the inductive coil-based device to possess a practical ability to detect a change in the tissue/fluid ratio in the head. Significance This study is an important step towards the goal of building an inexpensive and safe device that can detect an early brain hemorrhagic stroke.

scholarly journals Long Range Backhaul Microwave Connectivity in Wireless Sensor Networks via a New Antenna Designed for ISM 2.4 GHz Band

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Syed Mushhad Mustuzhar Gilani ◽  
Muhammad Tamur Sultan ◽  
Zeng Shuai ◽  
Asif Kabir
Keyword(s):  
Wireless Sensor Networks ◽  
Sensor Networks ◽  
Long Range ◽  
Wireless Sensor ◽  
Impedance Bandwidth ◽  
Antenna Gain ◽  
Frequency Range ◽  
Entire Frequency Range ◽  
Operating Bandwidth ◽  
Point To Point

This study aimed to explore a metallic striped grid array planar antenna, analyze it numerically in terms of its parameters, and optimize it for best performance. It may be an appropriate candidate for long-range point-to-point connectivity in wireless sensor networks. Antenna gain and frequency impedance bandwidth are two important performance parameters. For an efficient antenna, its gain should be high while maintaining operating bandwidth wide enough to accommodate the entire frequency range for which it has been designed. Concurrently, antenna size should also be small. In this study, antenna dimensions were kept as small as possible without compromising its performance. Its dimensions were 300 mm × 210 mm × 9.9 mm, which made it compact and miniature. It had a maximum gain of 16.72 dB at 2.45 GHz and maximum frequency impedance bandwidth of 7.68% relative to 50 Ω. It operated across a frequency band ranging from 2.38 GHz to 2.57 GHz, encapsulating the entire ISM 2.4 GHz band. Its radiation efficiency remained above 93% in this band with a maximum of 98.5% at 2.45 GHz. Moreover, it also had narrow HPBWs in horizontal and vertical planes having values of 18.52° and 31.25°, respectively.

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