Spectral shaping by generalized transfer function design in frequency modulation Sigma-Delta synthesizers. - Soeren R. Sappok; Andre Kruth; Guerkan Ordu; Ralf Wunderlich; Stefan Heinen (ISCAS (4), 2004)

Automated calibration technique for predistortion modulation loops using asynchronous phase detection. - Soeren R. Sappok; Andreas Neyer; Andre Kruth (Circuits, Signals, and Systems, 2005)