A Flexible Broadband Single RF Architecture Based on Time-Modulated Array
With a single RF front-end to equivalently realize RF transformation of multiple antenna elements, single RF array is an important way to reduce the manufacturing cost of massive MIMO systems. Time-division-multiplexing-based single RF array is suitable for uplink receiver array. However, there are some bottlenecks in broadband applications, such as very fast switching speed requirement of RF switch, wide bandwidth requirement of analog front-end and low signal fidelity, which stop the wide use of this technology. To overcome the above bottlenecks, a time-modulated-array-based broadband single RF receiver array architecture is proposed in this paper, and the theory of time-modulated array along with the idea of signal reconstruction is also introduced to broadband the single RF array. With these methods, the performance requirements of RF switching speed and analog front-end are expected to be reduced significantly while the signal fidelity degradation can be safely ignored. The experimental results show that the proposed architecture can improve the bandwidth of the system with traditional RF switching elements.
KeywordsSingle RF array Time-modulated array Massive MIMO Signal reconstruction Time-division multiplexing
This work was supported by the National Natural Science Foundation of China (NSFC) under Grant 61604054, and Shanghai Aerospace Science and Technology Innovation Fund (SAST2016097, SAST2017112).