This article reports a channel-selection N-path passive low-noise amplifier (pLNA) featuring only switches, capacitors, and a step-up transformer (i.e. a SCT network) to build a highly linear, frequency-tunable, and high-Q bandpass response with in-band voltage gain and input-impedance matching. We also reveal the inductive and lowpass properties of the step-up transformer, composed of two vertically coupled spiral coils, for passband centering with the local oscillator (LO) frequency, and harmonic-folding reduction. Prototyped in 28 nm CMOS, a 4-path 20 MHz-bandwidth pLNA scores a 9.8 dB voltage gain and a 3.4–4.8 dB NF over a 1.7–3.6 GHz range. At 3 GHz, the out-of-band (OB)-IIP ₃ measures +23.5 dBm, and the 3rd-harmonic-folding rejection ratio (HFRR ₃ ) is 33 dB. With a blocker applied at the 80 MHz offset, the blocker −1 dB compression point ( $\text{B}_{-1\,\text {dB}}$ ) attains +1.7 dBm, and the blocker NF only raises moderately to 4.7 dB up to a 0 dBm blocker power. The only dynamic power comes from the four-phase 25%-duty-cycle LO generator that consumes 17.8–38.2 mW between 1.7 and 3.6 GHz. The entire pLNA occupies a 0.84 mm ² die area.

中文翻译：

---

1.7–3.6 GHz 20 MHz 带宽通道选择 N 路径无源 LNA 使用开关电容变压器网络实现 23.5 dBm OB-IIP₃ 和 3.4–4.8 dB NF

本文报告了一种通道选择 N 路径无源低噪声放大器 (pLNA)，它仅具有开关、电容器和升压变压器（即 SCT 网络），以构建高度线性、频率可调和高 Q带内电压增益和输入阻抗匹配的带通响应。我们还揭示了升压变压器的电感和低通特性，升压变压器由两个垂直耦合的螺旋线圈组成，用于以本地振荡器 (LO) 频率为通带中心，并减少谐波折叠。采用 28 nm CMOS 原型制作的 4 路径 20 MHz 带宽 pLNA 在 1.7–3.6 GHz 范围内获得 9.8 dB 电压增益和 3.4–4.8 dB NF。在 3 GHz 时，带外 (OB)-IIP ₃测量值为 +23.5 dBm，3 次谐波折叠抑制比 (HFRR ₃ ) 为 33 分贝。在 80 MHz 偏移处应用阻塞器时，阻塞器 −1 dB 压缩点 ( $\text{B}_{-1\,\text {dB}}$ ) 达到 +1.7 dBm，并且阻塞器 NF 在阻塞器功率为 0 dBm 时仅适度提高到 4.7 dB。唯一的动态功率来自四相 25% 占空比 LO 发生器，它在 1.7 和 3.6 GHz 之间消耗 17.8–38.2 mW。整个 pLNA 占据 0.84 mm ²的裸片面积。