| 摘要 |
PURPOSE:To measure the input and output impedances during large signal operation simultaneously and quickly with high accuracy by controlling the tuners to be connected respectively to the input and output terminals of a transistor to be measured directly and digitally with an open loop system by means of a digital arithmetic control part. CONSTITUTION:Tuners 22, 23 are connected respectively to the input the output terminals of a transistor 21 to be measured used at high frequencies such as UHF. When a measurement start instruction is given, a digitl arithmetic control part 26 controls the tuner 22 in such a way that the output of a data collecting part 25 goes maximum and stores the output obtained by this in a storage part 27 (1). It stores the max. value of the output obtained by controlling the tuner 23 in a storage part 28 (2). Next, it compares the contents of the parts 27, 28, and when they coincide within a preset error range, the value thereof is selected as the max. output value, and the controlling of the tuners 22, 23 is completed. After the end of this control, the input and output impedances of the transistors 21 are measured from the corresponding data stored in the part 24 in accordance with the final flag position information of the tuner 22, 23. |
