| 摘要 |
PURPOSE:To measure electric powers of a wide range from low to high electric powers by providing a semiconductor amplitude limiter to a high frequency input terminal. CONSTITUTION:When an incident electric power is below the prescribed limit value of a semiconductor amplitude limiter 2, the high frequency electric power inputted to a waveguide 1 passes as it is through the limiter 2, and is inputted to the thermistor of a conversion part 3. The output of the part 3 is inputted to an incident high frequency electric power calculating part 4, and the high frequency electric power is displayed in a display part 5. On the other hand, when the incident electric power is in excess of the limit value, the limiter 2 limits the electric power incident to the part 3 and the limited electric power is proportional to the rectifying electric current 6 of a PIN diode 7. The sum of the value obtained by multiplying this current 6 by a conversion constant and the electric power past the limiter 2 is determined by the part 4, whereby the incident electric power is measured. Thereby, the burning of the thermistor due to the high electric power is prevented and the electric powers of a wide range are measured. |
