Low-voltage current-mode integrator for channel selection filter

A low-voltage current-mode integrator is presented for a continuous-time baseband channel selection filter of wireless communication systems. Fully-balanced current-mirror structure with additional cascode transistors operated in linear region enables low-voltage and low-power dissipation properties as well as voltage-controllable cutoff frequencies over a broad frequency range. A channel selection filter using the proposed integrator for three different communication standards with direct conversion receiver is implemented for a design example. Experimental results show that the implemented channel selection filter achieves design specification and outperforms other conventional filters.