设计大功率晶体管放大器要知道一个晶体管对某一输出功率和效率所要的串联输入阻抗和集电极负载阻抗;知道在一个宽频带范围内的这些参数将大大地简化电路设计,并可采用计算机辅助设计。由于大多数功率管是丙类工作(因此是非线性的),不能简单地使用散射参数或 S 参数。因此有时就必须进行自己的晶体管阻抗测量。首先是确定晶体管的串联输入阻抗 Zin 和串联集电极负载阻抗 Zcl。用图3a 所示的测试装 Designing a High Power Transistor Amplifier To know the series input impedance and the collector load impedance of a transistor for a given output power and efficiency; knowing that these parameters over a wide frequency band will greatly simplify the circuit design and may use computer-aided design . Since most power transistors are Class C (and therefore non-linear), you can not simply use scattering or S-parameters. So sometimes you have to make your own transistor impedance measurement. The first is to determine the series input impedance Zin of the transistor and the series collector load impedance Zcl. Use the test set shown in Figure 3a