3B40.30 - Doppler Effect - Microwave Beats

Set the microwave receiver pointing in the same direction as the transmitter and move just far enough in front of the transmitter to get a faint signal.  As the mirror is moved closer and farther away from the transmitter a beat frequency should be observed that is proportional to the speed of the mirror.
Code Number:
3B40.30
Demo Title:
Doppler Effect - Microwave Beats
Condition:
Excellent
Principle:
Doppler Effect Using Microwaves
Area of Study:
Acoustics
Equipment:
Amplifier, speaker, microwave transmitter and receiver, mirror plate.
Procedure:

Set the microwave receiver pointing in the same direction as the transmitter and move just far enough in front of the transmitter to get a faint signal.  As the mirror is moved closer and farther away from the transmitter a beat frequency should be observed that is proportional to the speed of the mirror.

References:
  • Richard W. Cole, "Demonstration Doppler Radar", TPT, Vol. 10, # 7, Oct. 1972, p. 399.
  • F. Neff Weber, Paul Helminger, and Doelores Lynn Moulds, "Student Microwave Experiments Involving the Doppler Effect", AJP, Vol. 48, #9, Sept. 1980, p. 737.
  • Raymond M. Kosiewicz, The Doppler Effect and Lissajous Figures Using a Linear Air Track", AJP, Vol. 39, #2, Feb. 1971, p. 229.
  • S. C. Bloch, W. E. Abare and G. E. Pidick, "Interference-Fringe Counting as an Aspect of Doppler Shift", AJP, Vol. 35, # 3, March 1967, p. 223.
  • F. D. Manchester, "Simple Doppler-Shift Apparatus Using Microwaves", AJP, Vol. 33, #6, June 1965, p. 499. 


Disclaimer: These demonstrations are provided only for illustrative use by persons affiliated with The University of Iowa and only under the direction of a trained instructor or physicist.  The University of Iowa is not responsible for demonstrations performed by those using their own equipment or who choose to use this reference material for their own purpose.  The demonstrations included here are within the public domain and can be found in materials contained in libraries, bookstores, and through electronic sources.  Performing all or any portion of any of these demonstrations, with or without revisions not depicted here entails inherent risks.  These risks include, without limitation, bodily injury (and possibly death), including risks to health that may be temporary or permanent and that may exacerbate a pre-existing medical condition; and property loss or damage.  Anyone performing any part of these demonstrations, even with revisions, knowingly and voluntarily assumes all risks associated with them.