28 GHz RF Front-End Structure Using CG LNA as a Switch
28 GHz RF Front-End Structure Using CG LNA as a Switch
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使用 CG LNA 作为开关的 28 GHz RF 前端结构
DOI：
10.1109/lmwc.2019.2951519
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发表时间：
2020
影响因子：
3
通讯作者：
Songcheol Hong
中科院分区：
文献类型：
--
作者：
Wonho Lee;Songcheol Hong
这封信提出了一种紧凑的28 GHz前端（FE）结构，使用共栅（CG）低噪声放大器（LNA）作为发送/接收开关。功率放大器（PA）输出与CG LNA输入共享直流偏置。当共享直流偏置为高时，LNA的状态变为无源，并且LNA在发射机（TX）模式下作为关断分流开关工作。所提出的CG LNA开关具有高隔离度和线性度，在28 GHz时TX路径插入损耗为0.07 dB。相反，当共享直流偏置较低时，PA的状态变为无源，并且在28 GHz时导致0.51 dB的接收器（RX）路径插入损耗。CG LNA开关的路径损耗通过PA和CG LNA的RF浮体最小化。这是在一个65纳米CMOS工艺占用0.215平方毫米的核心面积。在TX模式下，测得的饱和功率为15.3 dBm，峰值功率附加效率为25.1%，在RX模式下测得的噪声系数为4.9 dB。
This letter proposes a compact 28-GHz front-end (FE) structure that uses a common-gate (CG) low-noise amplifier (LNA) as a transmit/receive switch. The power amplifier (PA) output shares a dc bias with the CG LNA input. When the shared dc bias is high, the state of the LNA becomes passive, and the LNA operates as a turned-off shunt switch in the transmitter (TX) mode. The proposed CG LNA switch allows high isolation and linearity with a TX path insertion loss of 0.07 dB at 28 GHz. On the contrary, when the shared dc bias is low, the state of the PA becomes passive and it results in a receiver (RX) path insertion loss of 0.51 dB at 28 GHz. The path losses of the CG LNA switch are minimized by the RF floating bodies of the PA and the CG LNA. This is implemented in a 65-nm CMOS process occupying a 0.215-mm2 core area. The measured saturation power is 15.3 dBm with 25.1% peak power-added efficiency in the TX mode, and the measured noise figure is 4.9 dB in the RX mode.