A radar circuit for use with a host system such as a vehicle includes a radio frequency (RF) signal generator configured to generate a predetermined RF waveform, an RF antenna connected to the RF signal generator, and an ECU which executes a method. As part of such a method, a signal generator transmits the RF waveform toward different radar target types, and receives return signatures reflected therefrom. The ECU receives the return signatures from the antenna, processes the return signatures via parallel constant false-alarm rate (CFAR) subdetectors each with defined cells under test to detect the target types as a set of detection events, merges the detection events into a merged set, and executes a control action aboard the host system responsive to the merged set. Each subdetector detects a corresponding one or more of the radar target types via corresponding detection parameters.