Patent ID: 7898465

Claim:
An electronically scanned radar system comprising: a transmitting antenna which is able to freely transmit a transmission signal constituted of a continuous wave in a manner of performing horizontal scanning in a radar scanning region having a minimum angle θ min and a maximum angle θ max ; a receiving antenna constituted of a plurality of array antenna elements which are arranged with predetermined spaces therebetween; mixers for mixing reception signals received by the respective receiving array antenna elements with the transmission signals to obtain beat signals; A/D converters for converting the beat signals of individual channels, which beat signals are obtained by the respective mixers, into digital signals; and a target detection section for detecting a distance to or/and a relative speed of a target on the basis of the reception data, which are the signals digitized by the A/D converter, characterized in that: spaces in the arrangement, i.e. non-uniform spaces, of the plurality of array antenna elements of the receiving array antenna are determined by: (1) grouping the array antenna elements into two, to express a set encompassing the groups by G(2,p) (where p is a serial number designated to all the conceivable grouping methods); (2) performing the grouping for every combination of the array antenna elements constituting the receiving array antenna; (3) obtaining a greatest common divisor as a greatest common divisor G gcd of inter-group element spaces, for a set {D gcd (1),D gcd (2)} that has, as components, greatest common divisors of inter-element spaces included in individual groups constituting each set G(2,p); and (4) allowing the greatest common divisor D gcd of inter-group element spaces not to exceed the following formula: [ Mathematical ⁢ ⁢ Expression ⁢ ⁢ 2 ] 2 × λ sin ⁡ ( θ max ) - sin ⁡ ( θ min ) (λ: a wavelength of a reception signal (incoming wave), θ max : a maximum angle of a transmission signal in a horizontal scanning range, and θ min : a minimum angle of a transmission signal in a horizontal scanning range).