An 8-10GHz Upconversion Mixer, with a Low-Frequency Calibration Loop Resulting in Better Than -73dBc In-Band Spurs: RFIC Interactive Forum

An 8–10GHz Upconversion Mixer, with a Low-Frequency Calibration Loop Resulting in Better Than -73dBc In-Band Spurs

Johan C.J.G. Withagen, A.J. Annema, Bram Nauta, F.E. van Vliet; University of Twente, The Netherlands

An 8–10 GHz X-band upconversion quadrature mixer stage implemented in 250 nm SiGe BiCMOS is presented. Orthogonality of the spurious responses caused by clock feed through, I/Q mismatch and baseband harmonics after self-mixing was exploited to realize a baseband calibration scheme reducing all in-band spurs down to below -73dBc, for baseband signals up to a bandwidth of 2MHz and with an IF center frequency up to 100MHz. Utilizing a low-frequency output spectrum analysis of an integrated self-mixer at the upconversion mixer o