| 摘要 |
PROBLEM TO BE SOLVED: To provide a carrier leak measurement apparatus for a double balanced mixer capable of simply measuring a carrier leak of a single DBM being a measurement object with very high accuracy even in the case of the DBM integrated with an orthogonal modulator without the need for using a network analyzer (NWA). SOLUTION: The measurement apparatus is provided with: an orthogonal carrier signal generating/switching section 17 for generating a pair of carrier signals whose phases differ by 90 degrees and switching the outputted carrier signal; an orthogonal modulator 14 comprising DBMs 11, 12 one of which is a measurement object, and an adder 13; a level measurement apparatus 23 for measuring an output signal level of the orthogonal modulator; voltage generators 21, 22 for generating a DC voltage applied to an IF input terminal of each DBM; a means 27 for obtaining a pair of first DC voltages designated to the voltage generator whose output signal level is minimum while each carrier signal is kept to a first state; a means 27 for obtaining a pair of second DC voltages designated to the voltage generator whose output signal level is minimum while each carrier signal is kept to a second state; and a means 29 for calculating carrier leak of each DBM on the basis of a pair of the first and second DC voltages and a conversion coefficient of each DBM. COPYRIGHT: (C)2004,JPO&NCIPI
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