MIL MFDL 0517
Medium Wave Drive Test Antenna
The development of new standard such Digital Radio Mondiale (D.R.M.) on medium wave, requires to perform specific drive test in order to guarantee network quality in accordance to the international norms. Field measurements on travelling veichules, are not easy at this frequencies especially when done with electrical field antennas (eg. rods), because they ten to change the pattern depending from the ground distance and from the metal surface of the chassis, typically non ideal due the small dimensions.
The use of crossed magnetic loops antennas, avoids this issues because less sensitive to the ground capacitive effect and the reflection plane size. Due to this charapteristics, they have been largely used for years with MF and HF receivers and direction finders installed on ships and aircrafts.
MIL MFDL 0517 is an active crossed loop antenna, designed to measure the field coverage and propagation of medium wave networks (AM - DRM) and compatible to the ITU RECOMM. N° ITU-R 8S.703 (Annex 1 to Appendix 1).
The antenna consists of a couple of crossed shielded loops for HF, two independent pass band filters, two low noise amplifiers and one 90° hybrid combiner, to achieve the omni directional radiation pattern (see block diagram - picture 1).
More specification can been achieved by reading its complete data sheet (click to download)
Typ. radiation pattern at 1100 KHz
Schematic block diagram Eg. of typ. D.R.M . receiver plot with MFDL 0517 antenna
|Frequency range||500-1700 KHz|
|Typ. Gain||20 dB (a precise antenna factor table is given by default together the technical documentation)|
|Typ. Return Loss||20 dB|
|Rejection out of the band||> 30 dB @ 150 KHz
> 30 dB @ 3500 KHz
|IP3||30 dBm input (measured at each singular amplifier input)|
|NF||9.5 dB (measured at each singular amplifier input)|
|Power||+12 VDC @ 100mA|
|RF output||N precision bulkhead female|
|Loops Diameter||600 x
|Metal box size||210W x 245L x
|Accessories and parts delivered by default|
|DC Power cable (3 mt including