Design guide lines are given for developing SiGe HBT mm-wave d.c. coupled ultra-wide-band low noise monolithic amplifiers. An ultra wide band LNA and two mm-wave TIAs for 40 Gbps and 100 Gbps applications are proposed. The LNA has S 21 =11 dB and a 3-dB bandwidth of 88 GHz. The 40 Gbps TIA has a new topology, allowing a DC coupled performance, 54 dBΩ transimpedance gain, 37 GHz bandwidth, consumes 59 mW power and its area is 0.23 mm 2 . The 100 Gbps TIA has 43 dBΩ transimpedance gain, 79.4 GHz bandwidth, consumes 37 mW power and its area is only 0.05 mm 2 . These amplifiers are implemented in a 0.12 µm SiGe HBT technology (f T = 350 GHz/f max = 450 GHz). Output eye diagram plots were obtained to verify their performances.