A 1V SiGe power amplifier for 81–86 GHz E-band

This paper presents an architecture for a SiGe E-band power amplifier using a stacked transformers for output power combination. According to simulations, at E-band frequencies, the power combiner consisting of two individual single turn transformers performs significantly better compared to a single common 2:1 transformer with two turns on the secondary side. The power combination allows for a low supply voltage of 1 V, which is beneficial since the supply can be shared between the power amplifier and the transceiver thereby eliminating the need of a separate voltage regulator. To improve the gain of the two-stage amplifier it employs a capacitive cross-coupling technique not yet seen in mm-wave SiGe PAs. The PA is designed in a SiGe process with fr = 200 GHz and achieves a power gain of 12dB, a saturated output power of 16dBm and a 14% peak PAE.