Rotor Effects on L-Band Signals Received by Helicopter Antennas. A Theoretical Study. Part I: Amplitude Reduction and Phase Shift. (Schielding Effect).
ARMY ELECTRONICS COMMAND FORT MONMOUTH N J
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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
- Radiofrequency Wave Propagation