Short wire as a microwave analogue to molecular Raman scatterers

The frequency changes in the spectra of microwave radiation reflected from rotating or vibrating short wires are strongly reminiscent of optical Raman spectra from rotating or vibrating molecules. The analogy is examined and found to be quite good for rotation, although less so for vibration. The effect of rotation of the wire is an amplitude modulation, whereas that of vibration is a pulse modulation. The relation betwen the change in freauencv and the Doppler effect is also examined, since the rotational effect may be considered as a classical, first-order, ond-order Doppler effect. transverse Doppler shift completely unrelated to the relativistic second-order Doppler effect.