27 February 1981 Frequency Modulated (FM) And Amplitude Modulated (AM) In Millimeter Radar Due To Vibrating Structures
Author Affiliations +
Proceedings Volume 0259, Millimeter Optics; (1981) https://doi.org/10.1117/12.959659
Event: 1980 Huntsville Technical Symposium, 1980, Huntsville, United States
A theoretical analysis of the spectral content of a frequency modulated (FM) and amplitude modulated (AM) electromagnetic plane wave is presented. An unmodulated transmitted millimeter wave is modulated when reflected from a sinusoidally oscillating structure. The FM results from the doppler effect, while AM results from the optical properties (antenna beamwidths, radar cross sections (RCS)) of millimeter waves. The purpose of the analysis is to investigate the effect of the AM on the spectral lines resulting from FM. It is anticipated that AM is largely due to the RCS characteristics of the vibrating structure. For FM only, the amplitude of the first side band (spectral line) is maximized when the transmitted wavelength is approximately seven times the structure oscillation displacement amplitude. When the waveform also has AM, the spectral line amplitudes are increased, and the maximization criterion no longer applies.
© (1981) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
P. Martin Alexander, "Frequency Modulated (FM) And Amplitude Modulated (AM) In Millimeter Radar Due To Vibrating Structures", Proc. SPIE 0259, Millimeter Optics, (27 February 1981); doi: 10.1117/12.959659; https://doi.org/10.1117/12.959659

Back to Top