Microwave speed meter

A meter for measuring the relative velocity of balls and the like employed in sporting activities comprising, in combination:

• diplexer means for generating a beam of object illuminating microwave energy, for receiving doppler shifted microwave energy reflected from the object and for detecting said reflected doppler shifted microwave energy to develop a difference signal having a coherent component the frequency of which is proportional to the relative velocity of the object;
• phase-locked loop means including clock signal generating means, said phase-locked loop means for synchronizing the frequency of said clock signal generating means to that of the coherent component of said difference signal and for developing a lock signal indicative of when such synchronization has been achieved;
• lock detector and timer and means responsive to said lock signal for developing a stabilization signal after the frequency of said clock signal generating means has been synchronized for a predetermined stabilization period;
• counter timing means responsive to said stabilization signal for developing a reset signal upon receipt of said stabilization signal and for developing a latch signal a predetermined count period thereafter;
• counter means reset by said reset signal for counting the cycles of said clock signal occurring between the occurrence of said reset and latch signals to develop a sum signal;
• and
• means responsive to said sum signal for displaying the relative velocity of the object.