Issue link: https://resources.system-analysis.cadence.com/i/1355089
mmWave Automotive Radar and Antenna System Development Using AWR Software 6 www.cadence.com/go/awr This relatively simple design can be used as a template for different PD applications. The radar signal is a function of pulse repetition frequency (PRF), power, and pulse width (duty cycle). These parameters can be modified for different cases. In the simulation, the radar signal also can be replaced by any defined signal through the data file reader in which the recorded or other custom data can be easily used. AWR VSS software provides the simulation and model capabilities to refine the radar architecture, implement increasingly accurate channel models (including multipath fading and ground clutter), and develop performance specifications for the transceiver link budget and detailed antenna radiation pattern requirements. The plots in Figure 6 show several simulation results, including the TX and RX chirp waveform, the antenna radiation pattern, and several system measurements, including the relative velocity and distance. In this simulation, the distance to the target is swept to reflect a vehicle that approaches and passes by a stationary radar, resulting in Doppler frequency that reverses the sign from negative to positive (red curve) and produces a null in relative distance as the target passes by the radar. In an automotive radar for ACC, the velocity and distance information would be used to alert the driver or take corrective action (such as applying brakes). Figure 6: Results of the simulation are shown in the system metrics graph Multi-Beam/Multi-Range A typical ACC stop-and-go system requires multiple short- and long-range radar sensors to detect nearby vehicles. The shorter range radar typically covers up to 60m with an angle coverage up to ±45 ◦ , allowing the detection of the vehicle's adjacent lanes that may cut into the current travel lane. The longer-range radar provides coverage up to 250m and an angle of ± 5 ◦ to ±10 ◦ to detect vehicles further ahead in the same lane. To support multiple ranges and scan angles, module manufacturers such as Bosch, DENSO, and Delphi have developed and integrated multi-range, multi-detection functionality into increasingly capable and cost-sensitive sensors using multichannel TX/RX architectures. These different ranges can be addressed with multi-beam/multi-range radar by employing radar technology such as FMCW and digital beamforming with antenna array design. Antenna A multimodal radar for an ACC system 2 based on an FMCW radar driving multiple antenna arrays is shown in Figure 7. This multi-beam/multi-range radar with digital beamforming operates at both 24 and 77GHz, utilizing two switching-array antennas to enable long-range and narrow-angle coverage (150m, ±10 ◦ ) and short-range and wide-angle coverage (60 m, ±30 ◦ ). This example illustrates the use of multiple antenna-array systems, including multiple (5x12 element) series-fed patch arrays (SFPAs) for long-range, narrow-angle detection (77GHz), a single SFPA (1x12 elements designed for 24GHz) for short, wide-angle detection, and four (1x12) SFPAs for the receiver that were required for this type of system. Figure 7: Multi-beam/multi-range FMCW digital beamforming ACC radar