| 摘要 |
PROBLEM TO BE SOLVED: To provide a transmitter eliminating the unnecessary deterioration and stop of output of a transmission power amplifier, and performing a stable transmitting operation with an inexpensive configuration. SOLUTION: In the transmitter provided with: a power amplification part 12 which power amplifies an RF input; and a directional coupler 14 which couples the power-amplified RF input to an antenna 20, it is provided with a voltage variable attenuator (ATT) 11 at a prestage of the power amplification part, wherein the directional coupler detects and outputs travelling wave power and reflected wave power between the power amplification part and the antenna, a control device consisting of an FPGA determines a stable operating state of the transmitter, based on a value of the travelling wave power, calculates voltage standing wave ratio by values of the travelling wave power and the reflected wave power, and compares the calculated standing wave ratio with a threshold to control the power amplification of a high frequency signal in the power amplification part. COPYRIGHT: (C)2011,JPO&INPIT
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