Fm pulse radar system

Claim 1

A PULSED RADAR SYSTEM COMPRISING A SOURCE OF WAVES CYCLICALLY FREQUENCY MODULATED AT A PREDETERMINED RECURRENCE FREQUENCY; MEANS FOR TRANSMITTING PULSES OF WAVES FREQUENCY MODULATED IN CORRESPONDENCE WITH THE WAVES FROM SAID SOURCE; MEANS FOR RECEIVING REFLECTED ECHO PULSES; MEANS FOR DERIVING FROM RECEIVED ECHO PULSES SIGNALS FREQUENCY MODULATED IN CORRESPONDENCE THEREWITH; A DELAY LINE OF LENGTH EQUAL TO THE PERIOD OF CYCLIC RECURRENCE OF FREQUENCY MODULATION OF THE WAVES FROM SAID SOURCE AND HAVING A PLURALITY OF TERMINALS EACH SEPARATED FROM THE NEXT BY A PORTION OF LINE HAVING A DELAY EQUAL TO A FRACTION OF SAID PERIOD; A PLURALITY OF MIXERS EACH CONNECTED TO MIX TWO INPUTS, ONE INPUT COMPRISING THE WAVES FROM SAID SOURCE AND ONE COMPRISING SAID DERIVED SIGNALS, ONE OF THE TWO INPUTS TO EACH MIXER BEING FED DIRECTLY THERETO AND THE OTHER BEING FED THERETO VIA A DIFFERENT TERMINAL TO SAID DELAY LINE WHEREBY THE SAID OTHER INPUTS TO THE DIFFERENT MIXERS ARE DELAYED BY AMOUNTS DIFFERING FROM ONE ANOTHER BY THE DELAYS OF SAID PORTIONS OF THE DELAY LINE; A PLURALITY OF SIMILAR GROUPS OF NARROW BAND FILTERS, EACH GROUP OF FILTERS BEING FED WITH THE OUTPUT OF A DIFFERENT MIXER AND THE FILTERS OF EACH GROUP HAVING DIFFERENT BUT ADJACENT PASS BANDS; AND MEANS FOR UTILISING THE OUTPUTS OF SAID FILTERS FOR PROVIDING TARGET RANGE INFORMATION.