| 摘要 |
PURPOSE:To enable measuring of an accurate power gain even if a reflection power varies, by a method wherein an input is caused to change corresponding to the reflection power. CONSTITUTION:An input signal to a transistor to be measured, generated from a high-frequency signal generator 10, is supplied to a transistor 13 to be measured via a directional coupler 12. High-frequency wattmeters 15 and 16 are connected to the directional coupler 12, so that an input power P15 and a reflection power P16 can be detected individually. A control part 17 supplies a power (P15-P16) of a difference between the detection signals as a control signal to the high-frequency signal generator 10 to constitute a negative feedback loop. The input power to the measured high-frequency transistor 13 is represented by an equality of PIN=P15- P16-PLOSS, where PLOSS is constant and can be corrected. The input power can be substantially represented into an equality of PIN=P15-P16. This permits the reliable measurement of a power grain without being influenced by a variation in the reflection power. |
