In this study, a gallium nitride (GaN)-based current linear regulator (GBCLR) was developed and implemented to control 450 nm laser diodes, and the laser beams could be concentrated by the fiber optic cable. The GBCLR consisted of a GaN high-electron-mobility transistor (HEMT) and wide-bandwidth operational amplifiers. When using the GBCLR, the driving current of the laser diode can be operated in either continuous constant-current mode for a continuous-wave laser or pulse-width modulation mode to achieve a short-pulsed time laser. In the high-frequency pulse-width modulation mode of the GBCLR, the parasitic elements of the GaN HEMT, laser diodes, and printed circuit board must be evaluated because they can cause the gate–source voltage to overshoot and influence the laser operating current; however, few studies have analyzed these phenomena. This study adopted the complex equivalent circuits of the GaN HEMT and laser diode to establish a complete GBCLR simulation schematic with the same physical configurations and packages; thus, the GBCLR simulation circuit was able to obtain the critical simulation waveform, and the unknown parasitic element parameters could be inferred for the GBCLR design. However, the complete equivalent circuit of the GBCLR was quite complex; therefore, this study proposed a new simplified model and method to demonstrate that this method was practicable. Finally, a GBCLR prototype was developed, and the critical experimental waveforms were measured to verify the simulations and analyses.

中文翻译：

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采用简化的电阻-电感-电容等效电路来分析和确认用于激光二极管控制的氮化镓基电流线性稳压器

在这项研究中，开发并实施了一种基于氮化镓 (GaN) 的电流线性调节器 (GBCLR) 来控制 450 nm 激光二极管，并且可以通过光纤电缆集中激光束。GBCLR 由 GaN 高电子迁移率晶体管 (HEMT) 和宽带运算放大器组成。使用GBCLR时，激光二极管的驱动电流可以在连续恒流模式下工作，用于连续波激光器，也可以在脉宽调制模式下工作，以实现短脉冲时间激光器。在GBCLR的高频脉宽调制模式下，必须评估GaN HEMT、激光二极管和印刷电路板的寄生元件，因为它们会导致栅源电压过冲并影响激光器工作电流；然而，很少有研究分析这些现象。本研究采用GaN HEMT和激光二极管的复杂等效电路，建立了具有相同物理配置和封装的完整GBCLR仿真原理图；因此，GBCLR 仿真电路能够获得关键的仿真波形，并且可以为 GBCLR 设计推断未知的寄生元件参数。然而，GBCLR 的完整等效电路相当复杂。因此，本研究提出了一种新的简化模型和方法，以证明该方法是可行的。最后，开发了一个 GBCLR 原型，并测量了关键的实验波形，以验证模拟和分析。