A Q-band compact two-way 3dB Wilkinson power divider is developed using asymmetrical shunt-stub and meander lines. The prototype is fabricated in a 90nm CMOS technology. The measurement results, which match the 50 Ω system, reveal an equal power-split with the insertion losses (S21 and S31) of 3.9 ± 0.3dB from 40 to 50 GHz. The return loss at every port (S11, S22 and S33) is better than 12dB from 40 to 50 GHz, and the isolation (S23) is better than 18dB over the same frequency range. The intrinsic area of the prototype is 185 μm × 320 μm without contact pads, which is only 0.059 mm2. Comparison with some previous reported miniaturized on-chip Wilkinson power dividers over other frequency bands is given in the end of this paper.