AI 中文总结
本文针对6G通信的FR3频段，从硬件设计角度研究混频器优先接收机，明确其可行技术、设计权衡，利用变频特性实现频率捷变与抗干扰，为该类接收机的FR3应用提供设计依据。
AI 中文摘要
频率范围3（FR3）覆盖7.125-24.25 GHz，是6G通信的极具潜力的候选频段，它衔接了sub-6 GHz频段的覆盖范围与毫米波频段的容量。其频谱存在 incumbent密集且非连续的特点，要求接收机（RX）具备频率捷变性和抗干扰能力，能够在碎片化的子频段间跳变，同时承受强阻塞信号。混频器优先（mixer-first）接收机非常适合这一应用场景，但针对FR3的混频器优先接收机设计尚未得到系统研究。本文从硬件设计视角研究面向FR3的混频器优先接收机，在FR3特有的约束下评估选择性增强、谐波抑制、线性化、低噪声设计以及多相时钟生成。分析确定了可行技术、基本限制以及电路级和架构级的设计权衡。核心见解是，混频器优先接收机的变频特性允许选择性、线性化和噪声抵消部分在基带实现并转换到射频，从而支持频率捷变的FR3操作，同时将主要设计约束转移到混频器寄生参数、基带电路鲁棒性以及多相时钟生成。
英文摘要
Frequency Range 3 (FR3), spanning 7.125-24.25 GHz, is a promising candidate band for 6G communications, bridging the coverage of sub-6 GHz bands and the capacity of millimeter-wave frequencies. Its incumbent-dense and non-contiguous spectrum demands frequency-agile, interference-tolerant receivers (RXs) capable of hopping across fragmented sub-bands while withstanding strong blockers. Mixer-first RXs are well suited to this role, yet their design for FR3 has not been systematically addressed. This paper presents a hardware design perspective on mixer-first RXs for FR3, evaluating selectivity enhancement, harmonic rejection, linearization, low-noise design, and multi-phase clock generation under FR3-specific constraints. The analysis identifies viable techniques, fundamental limitations, and circuit- and architecture-level design tradeoffs. A central insight is that the frequency-translational property of mixer-first RXs allows selectivity, linearization, and noise cancellation to be implemented partly at baseband and translated to RF, enabling frequency-agile FR3 operation while shifting the dominant design constraints to mixer parasitics, baseband circuit robustness, and multi-phase clock generation.
