Due to technology trends such as autonomous driving, the need for robust safety in the automotive industry increases. The safety comes from sensors that are able to image the environment and systems that use this information to avoid incidents and retain maximum safety. Detection of pedestrian has high importance since a missed detection can be lethal. Current solutions for pedestrian detection are based on infrared and optical cameras. With these solutions it can be challenging to detect pedestrians under conditions such as cold/foggy conditions, especially during nighttime. In this scenario through clothes penetration of infrared radiation is poor. Instead, terahertz radiation penetrates better through clothes, making terahertz imagers a viable solution to increase safety in the framework of autonomous driving. The focus on automotive sensors requires that the solution needs to be low-cost, low power and compact. Traditional passive terahertz detectors are based on cryogenically cooling or active illumination of the target to maximize the sensitivity, since this is not applicable in automotive designs we design an array that can be combined with direct detectors to increases the sensitivity by maximizing the effective bandwidth. The sensor needs to have sufficient resolution to detect the pedestrians at distances up to 10 meters combined with sufficient sensitivity to also perform in weather conditions such as fog.