While purely digital phased arrays were once discarded as simultaneous transmit and receive (STAR) capable platforms, this notion has recently been reconsidered. Previous work demonstrated that adaptive digital beamforming and digital self-interference cancellation (SIC) can enable transmitting and receiving subapertures in an array to operate simultaneously in the same frequency band. This approach, referred to as Aperture-Level Simultaneous Transmit and Receive (ALSTAR), uses only adaptive digital beamforming and digital SIC techniques. The ALSTAR architecture does not require custom radiators or analog canceling circuits that can increase front end losses and add significant size, weight, and cost to the array. This paper extends the previously proposed effective isotropic isolation (EII) metric to account for fixed dynamic range transmit and receive channels. An alternating optimization procedure that exploits the interdependence of the transmit and receive beamformers is proposed based on the symmetry of the EII metric, achieving higher EII than in previous work. This optimization procedure balances the goal of null-placement for interference and noise rejection with the goal of maintaining high transmit and receive gain. Simulated results are presented for a $\mathbf {50}$-element array that achieves $\mathbf {187.1}$ dB of EII in narrowband operation with $\mathbf {2500}$ W of transmit power. We explore the effectiveness of the architecture and proposed optimization methods by demonstrating the high EII achieved across the full scan space of the array at several transmit power levels. Results are also presented for a regularized version of the beamformer optimization problem that allows the designer to trade EII for array gain.

中文翻译：

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使用数字相控阵实现孔径级同步发送和接收

虽然纯数字相控阵曾经作为同时发送和接收 (STAR) 能力的平台而被丢弃，但这个概念最近被重新考虑。先前的工作表明，自适应数字波束成形和数字自干扰消除 (SIC) 可以使阵列中的发射和接收子孔径在同一频段内同时运行。这种方法称为孔径级同步发送和接收 (ALSTAR)，仅使用自适应数字波束成形和数字 SIC 技术。ALSTAR 架构不需要定制辐射器或模拟消除电路，这些电路会增加前端损耗并显着增加阵列的尺寸、重量和成本。本文扩展了先前提出的有效各向同性隔离 (EII) 指标，以考虑固定动态范围的发射和接收通道。基于 EII 度量的对称性，提出了一种利用发射和接收波束成形器相互依赖性的交替优化程序，实现了比以前工作更高的 EII。该优化过程平衡了干扰和噪声抑制的零位放置目标与保持高发射和接收增益的目标。模拟结果显示为 该优化过程平衡了干扰和噪声抑制的零位放置目标与保持高发射和接收增益的目标。模拟结果显示为 该优化过程平衡了干扰和噪声抑制的零位放置目标与保持高发射和接收增益的目标。模拟结果显示为$\mathbf {50}$- 实现的元素数组 $\mathbf {187.1}$ 窄带操作中 EII 的 dB $\mathbf {2500}$W 的发射功率。我们通过展示在多个发射功率水平下在阵列的全扫描空间上实现的高 EII 来探索架构和提出的优化方法的有效性。还提供了波束成形器优化问题的正则化版本的结果，该问题允许设计人员用 EII 交换阵列增益。