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Introduction. The aim of Part 1 of this Annex is to provide comprehensive and detailed information on the theoretical characteristics of HF transmitting antennas. The analytical approach followed is to calculate the pattern and directivity gain for any of the included antenna types.
OW ELEVATION ANGLE(a in Fig, 6). Therefore, to judge antenna performance, it is more useful to have an antenna pattern showing the radiation at 30. egrees or more above the horizon. Figure 8 is a diagram showing the signal strength (represented by vectors) radiated from a typical half-wave dipole anten.
The antenna selection chart in Fig. 66 gives some general guidelines for the choice of a suitable antenna for a given type of service according to the required distance range. Two different categories are considered: short distance and medium/long distance services.
This document describes how HF (13.56 MHz) antennas can be built and tuned so that their characteristics match the requirements of the Texas Instruments’ high performance S6000 and S6500 readers and third party RF modules.
Classic G5RV-Flat top T Radiation Patterns 300R feeder bottom @ +1m above “Real” Ground & Antenna optimised for SWR 1.53:1 @ 14.15 MHz G8ODE RSARS 1691 NOTES:-The MMANA Program comes with a library of antenna models, one of which is the G5RV. There are also some transmission lines modelled .
In HF broadcasting the antenna is the means by which the radio-frequency energy is directed towards the required service area. The selection of the right type of antenna will enhance the signal in this area, while reducing radiation in unwanted directions.
Schematic Diagram of Basic Antenna Parameters. bandwidth, efficiency, complex equivalent length.
