A high performance, low-cost automotive radar is designed by mounting receivers around a 3D printed Luneburg lens. With this configuration, the antenna radiation pattern is maintained for all angles, (which means no beam deformation). Further, the present radar is capable of performing detection at all azimuth and elevation angles with high angle resolution and broadband operation. The radar adaptively adjusts its spatial sensing pattern, sweeping frequency band, pulse repetition frequency and coherent processing interval according to the environment. This is accomplished by initially performing a rough scan, which updates sensing results via a narrow bandwidth waveform and wide beam scanning. When interested objects are identified, a high-resolution detailed scan is performed in a specific region of interest. In this way, a much more effective detection can be obtained. Moreover, a method of mitigating interference of the 3D printed Luneburg lens based radar and a method of improving the angle resolution using a lens based MIMO approach is disclosed.