A Series-fed Cavity-back Patch Array Antenna for a Miniaturized 77GHz Radar Module

A series-fed cavity-back patch array antenna for a miniaturized 77GHz radar module is presented in this paper. Inherently, the microstrip patch antenna has a wider bandwidth with a thicker substrate. However, a ground coplanar waveguide (GCPW) to feed the patch array antenna has less surface wave radiation loss with a thinner substrate. Therefore, a three-layer cavity-back patch array antenna is proposed to fulfil both requirements. Six 10-element series-fed arrays for the 77GHz radar module with the total dimensions of only 36(L) ×18(W)×7(T) mm
³
are designed. Good radiation properties in a bandwidth from 77 to 81GHz are obtained.