We studied the viability of the embedded wafer level ball grid array (eWLB) package environment as an antenna platform for 77 GHz automotive radar sensors and the effects of package fabrication tolerances on the antenna performance. The investigation of different antenna concepts in the eWLB package and their characterization methods are addressed. The design procedures for electrically large, differentially fed loop antennas in a multilayer package structure are introduced. Two different planar antennas are developed and measured in an eWLB package showing promising results such as a gain of 9 GHz and an impedance bandwidth of 8 GHz. An acceptable antenna performance is recorded within the tolerance limits. Therefore, the eWLB package is seen as an appropriate platform for mm-wave antennas and as a good candidate for an antenna-in-package (AiP) concept.