提出了一种基于三导体耦合线结构的毫米波Marchand巴伦的新型宽带模型.基于c模和π模理论，对三导体耦合线进行了分析并采用传输线和理想变压器对其建立了模型.通过电磁场仿真提取了模型参数并使用该耦合线模型建立了Marchand巴伦的模型.基于该模型，使用GaAs工艺设计了一种毫米波Marchand巴伦并进行了流片制造，所设计的巴伦工作在15~55 GHz频率范围，测试结果表明该巴伦具有较好的幅值和相位平衡度，同时验证了模型的准确性.

A novel broadband circuit model for millimeter-wave Marchand balun using three-conductor coupled line was proposed. Based on the c-mode and π-mode theory, the three-conductor coupled line was analyzed and modeled by the transmission line and several ideal transformers. The model parameters are extracted from the electromagnetic simulation and then the coupled line model is utilized to build the model of the Marchand balun. Using the proposed model, a millimeter-wave Marchand balun was designed and fabricated in GaAs process. The balun works at the frequency range from 15 GHz to 55 GHz, the measurement results show that the balun has good amplitude and phase imbalance performance and verify the model as well.