首页>
外国专利>
method for detection of quadraturmodulator - tru00e4gerleckeinstellpunkts through geometric analysis / kalkulationsverfahren, tru00e4gerleckeinstellverfahren and quadraturmodulationsvorrichtung
method for detection of quadraturmodulator - tru00e4gerleckeinstellpunkts through geometric analysis / kalkulationsverfahren, tru00e4gerleckeinstellverfahren and quadraturmodulationsvorrichtung
The first, second, and third pairs of DC voltages which set a modulated signal to a predetermined reference level while the levels of I and Q signals supplied to a quadrature modulator are set at "0" are sequentially obtained. On the basis of the first, second, and third pairs of DC voltages, at least three measurement points based on a combination of pairs of DC voltages which set the level of the modulated signal to the predetermined reference level are decided. The coordinates of the center of a virtual circle having the three measurement points positioned on its circumference are automatically calculated by a geometric analytical computation. Adjustment voltages to be added to the I and Q signals so as to cancel out a carrier leak contained in the modulated signal are obtained from the coordinates of the center. IMAGE
展开▼
