Cw radar system

Claim 1

A CW RADAR SYSTEM COMPRISING A MICROWAVE RF ENERGY SOURCE, A SOURCE OF CLOCK PULSES, MEANS FOR DERIVING A RANDOM PULSES CODE FROM SAID CLOCK PULSES, MEANS RESPONSIVE TO SAID RANDOM PULSE CODE SIGNALS FOR MODULATING THE OUTPUT FREQUENCY OF SAID RF ENERGY SUCH THAT THE PHASE OF THE OUTPUT RF ENERGY IS AT ONE PHASE LEVEL AT THE INITIATION OF EACH OF SAID CODE SIGNALS AND AT A SECOND PHASE LEVEL SHIFTED 180* WITH RESPECT TO SAID ONE PHASE LEVEL AT THE TERMINATION OF EACH OF SAID PULSE CODE SIGNALS, COMMON ANTENNA MEANS FOR RADIATING SAID ALTERNATELY PHASE SHIFTED RF ENERGY AND TO RECEIVE A WAVE REFLECTED FROM A DISTANT TARGET, SAID RECEIVED WAVE BEING DELAYED A PRESCRIBED TIME CORRESPONDING TO THE RANGE OF THE DISTANT TARGET, MEANS FOR MIXING SAID REFLECTED WAVE WITH A PORTION OF SAID RADIATED WAVE WHEREBY A BEAT VIDEO-FORM SIGNAL IS PRODUCED, MEANS RESPONSIVE TO SAID CLOCK PULSE SIGNALS FOR PRODUCING A TIME-DELAYED REPLICA OF SAID RF MODULATING SIGNAL, SAID TIME DELAY CORRESPONDING TO THE RANGE OF THE DISTANT TARGET, MEANS FOR GENERATING A SIGNAL AT ONE-HALF THE FREQUENCY OF SAID CLOCK PULSES, A FIRST COMPARISON CIRCUIT HAVING SAID BEAT VIDEO-FORM FREQUENCY APPLIED THERETO AS ONE INPUT, A SECOND INPUT SIGNAL APPLIED TO SAID FIRST COMPARISON MEANS, SAID SECOND INPUT SIGNAL BEING DERIVED FROM THE COMBINED OUTPUTS OF SAID RANDOM CODE SIGNALS, SAID ONEHALF CLOCKS FREQUENCY SIGNAL AND SAID TIME-DELAYED REPLICA SIGNAL TO PRODUCE A CODE-LIKE SIGNAL SUCH THAT THE OUTPUT OF SAID FIRST COMPARISON CIRCUIT COMPRISES A SIGNAL HAVING A STRONG COMPONENT AT SAID ONE-HALF CLOCK FREQUENCY, MEANS FOR AMPLYING SAID STRONG COMPONENT SIGNAL AT SAID ONE-HALF CLOCK FREQUENCY, AND A SECOND COMPARISON CIRCUIT RESPONSIVE TO SAID AMPLIFIED SIGNAL AND SAID ONE-HALF CLOCK PULSE FREQUENCY SIGNAL WHEREBY THERE IS PRODUCED AN AUDIO SIGNAL CORRESPONDING TO THE DOPPLER FREQUENCY OF SAID TARGET SIGNAL.