Linear low-power 13GHz SiGe-Bipolar modulator driver with 7 Vpp differential output voltage swing and on-chip bias tee

A linear driver amplifier IC with 7 V_pp differential output voltage swing in SiGe Bipolar Technology is presented. The driver includes a novel on-chip bias tee, which allows for energy savings in applications with AC coupled loads compared to a reference implementation without bias tee. In addition to a low-power design, the driver was optimized regarding mutual thermal coupling between the transistors, stability and avalanche breakdown. The linearity of the driver is well suited for the intended application in Ultra Dense Wavelength Division Multiplex (UDWDM) systems, where the third harmonic of the differential output must be attenuated by at least 25 dB (relative to the fundamental amplitude) within the complete operating frequency range from 1.3 GHz to 13 GHz. The complete driver chip draws 250 mA from a 6 V power supply.