Various examples pertaining to a sensor housing design for millimeter wave (mmWave) sensors are described. A sensor housing may include a radar sensor, a printed circuit board (PCB), a radome and a PCB holder. The radar sensor may be capable of emitting a radio wave. The PCB may have a first side and a second side opposite the first side with the radar sensor mounted on the first side thereof to form a PCB assembly (PCBA). The radome may include a cavity in which the PCBA is disposed. The PCB holder may be disposed along a circumference of an inner wall of the radome, and the PCB holder may be configured to hold the PCBA such that a distance between an inner surface of the radome and a side of the radar sensor facing the inner surface of the radome is proportional to half wavelength of the radio wave.