Accession Number:

AD0787363

Title:

Rotor Effects on L-Band Signals Received by Helicopter Antennas. A Theoretical Study. Part I: Amplitude Reduction and Phase Shift. (Schielding Effect).

Descriptive Note:

Final rept.,

Corporate Author:

ARMY ELECTRONICS COMMAND FORT MONMOUTH N J

Personal Author(s):

Report Date:

1974-09-01

Pagination or Media Count:

65.0

Abstract:

Rotor effects on L-band navigation signals received by helicopter antennas are examined theoretically. Two types of distortions are distinguished a the amplitude reduction and phase shift of CW-signals due to periodic shadowing of the antenna by the rotor shielding effect and b the distortion of phase reversals assumed to occur at predetermined intervals in the incident signals. Numerical evaluations have been performed using the pertinent dimensions of a UH-1 helicopter. It was found that the shielding effect may reduce the received power by 10 dB while the phase shift does not exceed 90 degrees. Modified author abstract

Subject Categories:

  • Radiofrequency Wave Propagation

Distribution Statement:

APPROVED FOR PUBLIC RELEASE