Traditionally when designing analog or hybrid beamforming solutions for mmWave the design has been targeting a single application. A certain antenna panel/array has been designed for a certain purpose, such as a handheld device, and if another mmWave transceiver architecture is needed for another application that needs more antennas, such as a fixed wireless access point, or a small base station, another larger antenna panel has typically needed to be designed.
The 5G-NR mmWave communication devices range from a simple IoT device, via smartphones and fixed wireless access points, to devices for non-terrestrial communication as well as base stations. Designing different antenna panels with analog beamforming solutions for each of these use cases comes with a cost.
It would be an advantage to develop a scalable beamforming solution covering several of the use cases above, thereby reducing the development cost and enabling innovation of potential not-yet-known applications (possibly having almost unlimited bandwidth) as is the case in the mmWave radio spectrum.
Fortunately a digital beamforming architecture where one integrates the radio transceiver (RF) chip and antenna in a single encapsulation has this scaling possibility. The radio chip comprises the analog front end radio components, including down and upconverters, taking the mmWave radio signal from mmWave radio frequency down to an analog baseband signal on the receiver side and converting the transmitted analog baseband signal to mmWave radio signals on the transmitter side. The analog zero-IF signals from the individual RFFE chips can be routed on the PCB to a central Digital Beamforming Accelerator (DBFA), while each RFFE chip remains close to its antennas to minimize mmWave routing. The DBFA digitizes these signals and performs the core digital beamforming processing, substantially reducing the data rates between the DBFA and the baseband processor. Control remains with the baseband.
This architecture supports antenna layouts and antenna counts tailored to the application. By combining distributed RFFE chips with DBFA processing, BeammWave enables scalable digital beamforming solutions for different coverage and performance requirements.
A more complex use case relates to a mmWave smartphone implementation. This needs to solve the challenges associated with handheld devices (these have been discussed in previous posts) and therefore needs a distributed antenna architecture with, say, 8-16 Antennas and RF chips, with the corresponding digital beamforming algorithms adapted to that number of antennas. Considering even more complexity, such as a Fixed Wireless Access Point, then 32-64 RF chips may be needed so as to achieve the desired data rate (several Gb/s).
The same set of mmW RF chips is reused for all types of devices. However, in order to meet any requirements for higher transmitting power and better receiver sensitivity, typical for more advanced use cases, then these are solved by adding more RF chips. The level of scaling can also continue to base stations, devices used for non-terrestrial communications such as drones and aeroplanes (requiring 100+ antennas) and to devices communicating with satellites (1000+ antennas). One can even imagine extending the scaling idea of digital beamforming radio architectures to inter-planetary and interstellar communication, where the number of antennas in these cases needs to be in the range of hundreds of thousands to hundreds of millions of antennas. However, there might be some challenges with the 5G latency requirements in the communication that need to be solved as well.
BeammWave develops a scalable digital beamforming architecture enabling the mmWave mass market on earth as well as in the sky.
