The research group led by Professor Peter Kinget at the Columbia University Integrated Systems Laboratory (CISL) focuses on cutting edge analog and RF circuit design using digital nanoscale CMOS processes. Key challenges in the design of these circuits include block-level characterization and full-circuit verification. This paper highlights these verification challenges by discussing the results of a 2.2 GHz PLL LC-VCO, a 12-bit pipeline ADC, and an ultra-wideband transceiver.