Modern handsets cater possibly tens of frequency bands ranging from hundreds of MHz up to several GHz. For antenna design this is a great challenge, as the handset itself is compact and there is little room for antennas. Moreover, the industrial design evolution has removed all external antennas from the handsets. Antenna engineers are employing ingenious methods to respond to these challenges, and one mainstream architecture involves so-called aperture tuning which re-uses a single radiator to optimally serve many different frequency bands. This webinar is about design of aperture tuning solution using simulation tools. Specifically, a design approach where circuit synthesis using Optenni Lab is combined with physical structure electromagnetic simulation using CST Microwave Studio is demonstrated. These tools are linked enabling automated co-optimization, resulting in optimized antenna mechanics and matching circuits in a single optimization.