Antonio Cantoni John Tuthill Digital Compensation of Frequency Dependent Imperfections in Direct Conversion I-Q Modulators. 269-272 2007 conf/iscas/2007 ISCAS http://doi.ieeecomputersociety.org/10.1109/ISCAS.2007.378387 db/conf/iscas/iscas2007.html#CantoniT07