Recently, mm-wave multi-in multi-out (MIMO) arrays are garnering significant attention because of their ability to form multiple spatial beams, achieving significantly higher data rates compared to traditional phased array-based approaches. Furthermore, scalable MIMO arrays can provide many other functionalities, such as full digital beamforming and per-power amplifier (PA) digital pre-distortion. In this work, an MIMO four-element TX array architecture is presented with a frequency-domain multiplexing-based single-wire interface (SWI), breaking the tradeoff between channel-to-channel isolation and single wire (SW) bandwidth (BW). The concept of harmonic-rejection mixing (HRM) is used to de-multiplex the four modulated signals simultaneously from the SW using a single passive mixer driven by a multi-phase local oscillator (LO). The two-stage harmonic recombination circuits are implemented in baseband and, hence, achieve high channel-to-channel isolation with a low power overhead. A 60-GHz four-element TX prototype demonstrates the proposed architecture in 45-nm RF silicon-on-insulator (RFSOI) CMOS. The frequency-division-multiplexed (FDM)-based SWI can support 8-GHz total intermediate frequency (IF) BW across the four channels with 30–40-dB channel-to-channel isolation. Each TX element in the array achieves 20–35-dB conversion gain and +8.8–10.9-dBm OP1dB while consuming 225 mW/element.

中文翻译：

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毫米波MIMO阵列中的频域复用单线接口和基于谐波抑制的IF数据解复用

近来，毫米波多进多出（MIMO）阵列由于能够形成多个空间波束而获得了广泛的关注，与传统的基于相控阵的方法相比，其数据速率显着提高。此外，可扩展的MIMO阵列可以提供许多其他功能，例如全数字波束成形和每功率放大器（PA）数字预失真。在这项工作中，提出了具有基于频域多路复用的单线接口（SWI）的MIMO四元素TX阵列架构，打破了通道间隔离和单线（SW）带宽（BW）之间的权衡问题。谐波抑制混合（HRM）的概念用于使用由多相本机振荡器（LO）驱动的单个无源混频器同时对来自SW的四个调制信号进行多路分解。两级谐波重组电路在基带中实现，因此可实现高通道间隔离，而功耗却较低。一个60 GHz四元素TX原型演示了在45 nm RF绝缘体上硅（RFSOI）CMOS中提出的架构。基于频分复用（FDM）的SWI可以在四个通道之间以30–40 dB的通道间隔离度支持8 GHz的总中频（IF）BW。阵列中的每个TX元件均可实现20–35 dB的转换增益和+ 8.8–10.9 dBm OP1dB，同时消耗225 mW /元件。基于频分复用（FDM）的SWI可以在四个通道之间以30–40 dB的通道间隔离度支持8 GHz的总中频（IF）BW。阵列中的每个TX元件均可实现20–35 dB的转换增益和+ 8.8–10.9 dBm OP1dB，同时消耗225 mW /元件。基于频分复用（FDM）的SWI可以在四个通道之间以30–40 dB的通道间隔离度支持8 GHz的总中频（IF）BW。阵列中的每个TX元件均可实现20–35 dB的转换增益和+ 8.8–10.9 dBm OP1dB，同时消耗225 mW /元件。