宽带相控阵列接收机前端CMOS单片实现技术的研究

Phased array systems which utilize multiple antennas to improve transceiving performance have been widely used for military purpose, and emerge recently for non-military applications. A traditional phased array system is mostly composed of commercial non-CMOS devices. With the development of phased array orienting to high integration and low cost, single-chip CMOS implementation of wideband phased array receiver front-end becomes a key technology worldwide. A wideband phased array receiver front-end circuit based on CMOS technology is proposed with wide instantaneous bandwidth at 24.25-26.65 GHz targeting 24 GHz short range vehicular radar. The influences of aperture effect and transit time are reduced by a kind of time delay circuits based on all-pass topology in order to increase the instantaneous bandwidth. A novel hybrid phase shifting method by LO phase shifter and mixer is proposed to avoid the degrading of the receiving performance by RF phase shifter, and to realize a highly accurate phase shifting by LO phase shifter. This work proves as an efficient solution for CMOS implementation of wideband phased array receiver, as it demonstrates a good performance in receiving and beam steering.

相控阵列系统使用多根天线来提高信号收发性能，这一技术已广泛应用于军事领域，近年来逐渐在民用领域兴起。传统的相控阵列系统大部分基于非CMOS工艺的商用芯片搭建。随着相控阵列技术向高集成度，低成本化的方向发展，宽带相控阵列接收机前端的CMOS单片实现成为国际国内的研究前沿。本课题提出基于CMOS工艺，具有较高瞬时带宽性能，工作在24.25-26.65 GHz频段，可用于24GHz短距离车载雷达的宽带相控阵列接收机前端电路。采用基于全通网络的延迟电路有效地降低了孔径效应、渡越时间的影响进而提高了瞬时带宽；同时提出了一种较为新颖的本振移相器和混频器联合移相的结构，既避免了射频移相器对接收性能的恶化，又能以较小的本振移相器精度实现较大的整体移相精度。所设计的前端电路具有良好的接收性能和波束控制性能，为CMOS宽带相控阵列接收机整机芯片实现提供了有效的解决方案。

相控阵列技术是近年来发展极为迅速的一项技术，尤其在5G通信和雷达系统中。由于宽带特性和苛刻的性能指标，传统相控阵列系统大部分基于III-V化合物商用芯片搭建而成。随着相控阵列技术向高集成度，低成本化的方向发展，宽带相控阵列接收机前端的CMOS单片实现成为国际国内的研究前沿。本课题针对24GHz短距离车载雷达应用提出了较为新颖的具有负群延时补偿的实时延时移相器射频相控阵接收机架构并完成芯片实现，解决了传统延时单元因为使用物理延迟线而带来的面积过大问题，同时也缓解了延时单元插损较大的问题。接收机前端电路具有良好的接收性能和波束控制性能，整体接收机最大时延432ps，精度达到6-bit，从而从理论上解决了相控阵系统的波束倾斜问题，使得系统中使用大瞬时带宽成为可能。同时本课题采用两点调制技术设计并芯片实现了雷达FMCW信号产生解决方案以及1.5GHz瞬时带宽的中频滤波和放大的芯片技术，为CMOS宽带相控阵列接收机整机芯片的实现提供了有效的解决方案。本课题研究成果无论是在汽车雷达、还是5G通信中都有着广阔的应用前景。课题组取得了32项科研成果，发表19篇学术论文和报告，其中：SCI期刊论文1篇；EI检索期刊论文1篇；核心期刊论文1篇；EI检索国际会议论文12篇；撰写出4篇硕士学位论文；申请13项国家发明专利。