An 8-way power-combining E-band amplifier in a SiGe HBT technology

An E-band power amplifier is demonstrated in an evaluation version of a f_T/f_max 300-GHz/450-GHz SiGe:C BiCMOS technology. Eight-way power combining of the outputs of transformer-matched differential-cascode unit cells is used in the final stage of the amplifier. A breakout of the final stage yields a measured small-signal gain of 14 dB at 80 GHz with a 16-GHz bandwidth, whereas a version of the amplifier with an integrated 4-way power-combined pre-driver provides 28 dB gain. In the 71-76-GHz sub-band, a saturated output power of 22 dBm with an output 1-dB compression point of 20 dBm is measured, while 19 dBm output power and a 17-dBm compression point is obtained in the 81-86-GHz band. The current consumption at a 3.3-V supply voltage is 330 mA for the output stage and 500 mA for the amplifier with an integrated pre-driver.