PURPOSE: To enhance phase stability by correcting set data of a phase shifter of an input stage of an amplifier in accordance with the fluctuation quantity of a transmission phase of the amplifier.
CONSTITUTION: An RF signal which has been generated by a high frequency signal generator 3 is set to a necessary phase by a phase shifter 2, amplified by an amplifier and transmitted. Based on the input RF signal of the amplifier 1 as a reference, the phase fluctuation quantity of an output RF signal of the amplifier 1 is detected by a phase detecting circuit 6. The detected phase fluctuation quantity is inputted to a phase setting circuit 7. This phase setting circuit 7 calculates phase setting data of a transmitting RF signal from a controller 4 and the phase fluctuation quantity sent from the phase detecting circuit 6, and gives the phase correction quantity to the phase shifter 2.
ICHIEDA MASAHIRO
HASEGAWA HIROSHI
MUTO NORIO
TAMII SEIZO
