Although there is a lot of discussion of massive MIMO and automotive radar, it should not be forgotten that most of the recent radar development and beamforming R&D has been in the defense industry, and it is now being adapted for commercial applications. While phased array and beamforming moved from R&D efforts to reality in the 2000s, a new wave of defense focused arrays are now expected, enabled by industrial technology offering solutions that were previously cost prohibitive. A generic beamforming phased array signal flow is shown in figure 2. The number of elements is chosen at the system architect level, based on aperture size, power, and antenna pattern requirements. Front-end modules are behind each antenna element.
An analog beamforming layer is behind the front-end modules. In classical phased arrays, the analog beamforming subsystem combines all the elements to centralized receiver channels. An every element digital beamforming phased array has waveform generators and receivers behind every front-end module, and the analog beamforming layer is eliminated. In many systems today, some level of analog beamforming is common. The waveform generator and receiver channels serve to convert digital data to the operating band RF frequencies.
Digital beamforming is accomplished by first equalizing the channels, then applying phase shifts and amplitude weights to the ADC data, followed by a summation of the ADC data across the array. Many beams can be formed simultaneously, limited only by digital processing capability. Analog Devices has solutions for every section of a beamforming system illustrated, and for both analog and digital beamforming architectures.