Optimization of High-Efficiency GaN Load Modulated Balanced Amplifier for Integrated Sensing and Communication Applications

作者：Luqi Yu, Yucheng Yu, Peng Chen, Chao Yu · 发表于：IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems · 年份：2024 · DOI：10.1109/tcad.2024.3416248 · 被引用次数：6 · 研究领域：GaN-based semiconductor devices and materials

The novelty of this article is proposing an optimization strategy to design a high-efficiency load modulated balanced amplifier (LMBA) for integrated sensing and communication applications. Taking account of the operating characteristics, theoretical analysis reveals that different load modulation factors of the LMBA need to be realized in Mode I for communication applications, and in Mode II for sensing applications, respectively. To address this issue, the proposed strategy is used to optimize the LMBA, so as to achieve good performance for both modes. To verify the proposed strategy, an LMBA prototype operating from 1.55 to 2.55 GHz is designed with the use of three commercial gallium nitride (GaN) transistors. When tested in Mode I, the LMBA achieves a 9-dB back-off efficiency of 50.1%–68.7% and a saturated efficiency of 65.0%–79.6%. When excited by a 60-MHz 5G new radio signal with a 9-dB peak-to-average power ratio, the adjacent channel power ratio of the LMBA in Mode I is from -45 to -52.2 dBc after digital predistortion with the average efficiency of 50.0%–66.9% over the entire bandwidth. When the LMBA is measured in Mode II, it achieves a saturated output power of 43.7–45.4 dBm and a saturated efficiency of 55.3%–72.2% from 1.55 to 2.55 GHz.