Commtel Wireless - overview

By: Commtel Wireless  09-12-2011
Keywords: Aircraft, Communication System, Antenna Systems

Antenna System Evaluation

Antennas Mounted on Large and Complex Structures

Overview - Experience and Capabilities in Aircraft Communication Systems Projects

  • Evaluation of radiation patterns from antennas mounted on aircraft.
  • Evaluation of coupling between antennas mounted on aircraft.
  • Evaluation of aircraft HF antenna near-fields.
  • Communications link evaluation (air-to-ground and air-to-air) for aircraft in the HF, VHP and UHF frequency bands.
  • Evaluation of aircraft antennas in terms of impedance and radiation performance.
  • Design, manufacture and commission of matching networks for aircraft antennas.
  • Design of low-profile broadband antennas for aircraft antennas.

Introduction

Companies engaged with aircraft communication systems are required to determine the antennas sitting on the aircraft. Antennas mounted on the aircraft do not act in isolation; they interact with other antennas and RF equipment in their vicinity, and their performances are affected by the structure on which they are mounted. Correct sitting of antennas on the aircraft is of vital importance to the overall communication system design.

Commtel-Wireless is equipped and qualified to perform this work having extensive experience in the development of antennas and antenna systems and more importantly in the radio communication systems employed on military aircraft. Much of our experience has been gained in on-going work on various aircraft. The work mainly involved evaluation, measurement and modifications to the existing and potentially suitable HF, VHP and UHF antenna systems on aircraft. Insight into practical constraints and requirements for aircraft antenna performance have been gained from interaction with pilots, squadron commanders, technical support personnel on both squadron, base and headquarter levels. A large part of this work involved the manufacture, installation and commissioning of matching networks on supersonic fighter planes in accordance with military aviation specifications.

Our experience in the field of computer aided development of antennas using the internationally recognized Numerical Electromagnetics Code (NEC) stretches over a much longer period. We have used this program to design and evaluate numerous antennas and structures including: Antennas on different helicopters, antennas on fighter aircraft, antennas on the transport aircraft such as the Dakota and the Hercules C130, antennas on locomotives, HF antennas on helicopters, HF broadband antenna design, commercial VHF/UHF antenna design, antenna farm coupling and layout evaluations, manpack and mobile VHF/UHF antenna evaluation and design and many other projects. In most cases the work was performed using both computer simulation and measurement in a complementary and cost effective fashion. We have experience in the development of commercial antennas from concept to final product which ensured that our experience with computational tools remains firmly rooted to the practical realities and anomalies found in real applications.

Keywords: Aircraft, Aircraft Antenna, Aircraft Antennas, Antenna System, Antenna Systems, Communication System, System Evaluation,

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Commtel Wireless - measured coupling between communication antennas mounted on aircraft scale model

The matching losses presented by the monopoles representing the V/UHF antennas are removed in the band when the measured couplings between these antennas are above the measurement system sensitivity. Indication of the coupling between the communication antennas at the respective communication frequencies is determined from measurements on a suitable scale model of the aircraft.


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Commtel Wireless - services

The company has developed antennas spanning a large frequency band—from 2MHz to 40GHz including HF broadband base station and tactical antennas, V/UHF antennas for base station and mobile applications, Microwave antennas for radar and other applications in the C, X, Ku, K & Ka bands and other RF circuits.


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Commtel Wireless - project list

Interim solutions for the VHF Antenna system mounted on the tail of the Cheetah aircraft for operation Golden-Eagle. Investigating additional antenna configurations/positions to improve communications on the Pilatus PC7 MK II. Measured coupling between communications Antennas mounted on a Rooivalk helicopter scale model. Radiation patterns study Department of Water Affairs repeater station on Impati Hill.


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Commtel Wireless - validation of aircraft numerical models

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