Title :
Relative tower currents and fields in an AM directional array
Author :
Hatfield, James B.
Author_Institution :
Hatfield & Dawson Consulting Eng., Seattle, WA, USA
fDate :
6/1/1989 12:00:00 AM
Abstract :
With the help of method-of-moments techniques, the antenna monitor parameters that give the correct pattern can be calculated from the field parameters. The base voltages can be computed from the linear relationship between the relative fields and the base voltages. The computed voltages can then be used as sources for MININEC III. The base currents computed by MININEC III for those base voltages are used to determine the antenna monitor parameters that result in the correct directional antenna (DA) pattern. Calculating the antenna monitor parameters that give the correct DA pattern means that trial and error field adjustment is not necessary in those situations where reradiating objects are not present. Thin reradiating objects, such as AC power transmission towers, can be included in the computation when they can be accurately located and described. Detuning impedances from the floated towers to ground are easily calculated from the output of the MININEC III program. Examples of the use of this technique are presented
Keywords :
amplitude modulation; antenna arrays; radio transmitters; AM directional array; MININEC III; antenna monitor parameters; base currents; base voltages; directional antenna; impedances; method-of-moments; pattern; radio transmitters; Antenna arrays; Condition monitoring; Current distribution; Directional antennas; Directive antennas; FCC; Phased arrays; Poles and towers; Shape; Voltage;
Journal_Title :
Broadcasting, IEEE Transactions on