A 28-GHz in-band full-duplex (IBFD) power amplifier (PA) is presented which integrates a PA with an impedance matched hybrid transformer in a 28-nm bulk CMOS process. The hybrid transformer has a 1:2 turn ratio to match from the optimum load impedance of $25~\Omega $ for a PA to the antenna and balance ports of $100~\Omega $ . Since this allows the additional matching circuits of a PA and an antenna to be obviated, the full-duplex loss is reduced. It shows 28.4-dB isolation between the PA and LNA ports at 28 GHz. For comparisons, a 50- $\Omega $ matched PA and an IBFD PA are designed. The IBFD PA has core sizes of $0.24\times 0.43\,\,{\text {m}}{\text {m}}^{2}$ . Since the impedance matched hybrid transformer has the similar size to the output matching network of the 50- $\Omega $ matched PA, a full duplexer is integrated into the PA without additional chip area. The IBFD PA has 10.6-dB gain and a drain efficiency of 8.9% at 12.3-dBm P1dB.

中文翻译：

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集成了阻抗匹配混合变压器的 28GHz 带内全双工功率放大器


提出了一种 28 GHz 带内全双工 (IBFD) 功率放大器 (PA)，该放大器在 28 nm 体 CMOS 工艺中集成了 PA 和阻抗匹配混合变压器。混合变压器具有 1:2 匝数比，可匹配 PA 的最佳负载阻抗 $25~\Omega $ 到天线和平衡端口 $100~\Omega $。由于这可以省去 PA 和天线的额外匹配电路，因此降低了全双工损耗。它显示 PA 和 LNA 端口之间在 28 GHz 时的隔离度为 28.4 dB。为了进行比较，设计了 50-$\Omega$ 匹配的 PA 和 IBFD PA。 IBFD PA 的核心尺寸为 $0.24\times 0.43\,\,{\text {m}}{\text {m}}^{2}$ 。由于阻抗匹配混合变压器的尺寸与 50Ω 匹配 PA 的输出匹配网络相似，因此将全双工器集成到 PA 中，无需额外的芯片面积。 IBFD PA 在 12.3dBm P1dB 时具有 10.6dB 增益和 8.9% 的漏极效率。