High efficiency patch antenna for 24 GHz anticollision radar

This paper presents design and measured results in synphase patch antenna for anticollision radar at 24 GHz. The antenna consists of two linear arrays of 24 serially connected patches. The aim was to design an antenna that in azimuth has lobes below -20 dB in ISM range of 24.05-24.25 GHz, at which the anticollision radar operates. The realized antenna has gain of 21.75 dB and efficiency of 60% at the frequency of 24.1 GHz. Three-decibel bandwidth in azimuth is 3.6/spl deg/ and in elevation is 46/spl deg/. In the range of 24.05-24.25 GHz, gain is higher than 21.15 dB and the reflection coefficient is below -14 dB.