System for lengthening the effective range of radar

• US 3,154,782 A
• Filed: 02/15/1960
• Issued: 10/27/1964
• Est. Priority Date: 01/01/1960
• Status: Expired due to Term

• Current Assignee: Yasutoshi Ishizaki, Yoichi Kagawa
• Original Assignee: Yasutoshi Ishizaki, Yoichi Kagawa
• Inventors: YOICHI KAGAWA, YASUTOSHI ISHIZAKI
• Application Number:
  US04/008,817
• Time in Patent Office: 1,716 Days
• US Class Current: 342/201
• CPC Class Codes: G01S 13/28 with time compression of received pulses

Claims

1. A RADAR SYSTEM COMPRISING MEANS FOR TRANSMITTING A MODULATED ELECTROMAGNETIC WAVE HAVING SUCH A FREQUENCY SPECTRUM THAT ALL PARTS THEREOF CANNOT COINCIDE IN PHASE AT ANY MOMENT, MEANS FOR RECEIVING ECHOES FROM TARGETS OF SAID TRANSMITTED ELECTROMAGNETIC WAVE, AN AMPLIFIER FOR SAID RECEIVED WAVES AND A CIRCUIT AT THE OUTPUT OF SAID AMPLIFIER CONSISTING OF FILTERS CONNECTED IN PARALLEL AND A PHASE SHIFTER CONNECTED IN TANDEM TO AT LEAST ONE OF SAID FILTERS TO CHANGE PHASES OF THE PARTS OF THE FREQUENCY SPECTRUM WHICH HAVE PASSED THROUGH SAID FILTERS SO THAT ALL PARTS OF THE SPECTRUM MAY COINCIDE IN PHASE AT SOME MOMENT TO FORM OUTPUT PULSES NARROWER IN WIDTH THAN INPUT SIGNALS WHEN THE OUTPUTS OF THESE PHASE SHIFTERS ARE COMBINED.

3. A RADAR TRANSMITTING SYSTEM COMPRISING A SOURCE OF A FIRST WAVE ENERGY OF A FIRST GIVEN FREQUENCY F0, ANOTHER SOURCE OF A SECOND WAVE ENERGY OF A SECOND GIVEN FREQUENCY F1 WHICH IS SMALLER THAN SAID FIRST FREQUENCY, MEANS FOR PRODUCING FROM THESE WAVE ENERGIES THIRD WAVE ENERGIES OF FREQUENCIES F0-F1 AND F0+F1, MEANS FOR COMBINING SAID FIRST WAVE ENERGY AND SAID PRODUCED THIRD WAVE ENERGIES TO PROVIDE A COMPLEX WAVE CONTAINING THIRD WAVE ENERGIES OF FREQUENCIES F0-F1, F0, AND F0+F1 AS COMPONENTS, A PULSE GENERATOR FOR PRODUCING PULSES OF A REPETITION RATE EQUAL TO A SUB-MULTIPLE OF SAID SECOND FREQUENCY F1, MEANS FOR AMPLITUDE-MODULATING SAID COMPLEX WAVE WITH SAID PULSES AT TIMES WHEN AT LEAST ONE OF SAID COMPONENTS HAS AN INSTANTANEOUS PHASE DIFFERING FROM THE OTHER COMPONENTS, AND MEANS FOR TRANSMITTING SAID MODULATED SIGNALS.