| 摘要 |
PURPOSE:To ensure an optional variation for the characteristics between the input electric power and the output phase, by connecting a directional coupler having an impedance control circuit to the input and output sides of a high frequency transistor amplifier. CONSTITUTION:A directional coupler 2 incorporating an impedance control circuit 3 and a matched load 5 is connected to either one of the input and output sides of a high frequency transistor amplifier 4. The greater part of the output of the amplifier 4 is supplied to a load 10, and a part of this output is applied to the circuit 3. The greater part of electric power reflected by the the circuit 3 is absorbed to the load 5, but a part of the reflected power is sent back again to the amplifier 4. This means that the load impedance characteristics viewed from the amplifier 4 has changed, but the impedance has no change when the amplifier 4 is viewed from the load 10. So is with the input side. Thus the load impedance characteristics is controlled freely by the circuit 3 and according to the coupling degree of the coupler 2. As a result, an optional variation is possible for the characteristics between the input electric power and the output phase. |
