Modeling and Optimization of a Range-Selective Digital Array Radar

The development of high-speed analog-to-digital converters (ADCs) facilitates starting the signal processing of received signals closer to the front end of transceivers, such as the ones used in digital radars, without the need of multiple downconversion stages. In this paper, we discuss the design parameters and optimization of a range-selective digital array radar to block interferences around the observed area. The radar system consists of a linear array of transmitters and a receiver where the frequency components received from each transmitter is filtered out and weighted individually to focus the beam at a certain angle and range. The beamforming process used the recursive multibeam techniques and Monte Carlo method and separately to optimize the frequency offsets between the transmitted carriers and, consequently, minimize the sidelobe level (SLL). Simulation results showed that the SLL was decreased to −16.67 dB in the angle domain and below −10 dB in the range domain at the intended location. The experimental testing of the system using a real multicarrier signal and a data acquisition board (DAQ) proved a similar SLL in the range domain below −10 dB.