Rectification ratio I (RRI; without unit) is calculated according to Equation 3 and expresses the ratio of the current (on CV curve) registered at the maximum voltage under "open" polarization (IO) to the current registered at the maximum voltage under "blocked" polarization (IB). We present a 3D-printed in-plane capacitive analogue of a diode controlled by a third "gate" electrode (G-CAPode). This device integrates diodic and transistor-like characteristics, functioning in electronic circuits as tunable high-and band-pass filters. It shows great potential as a silicon-free alternative for iontronic applications requiring precise current flow control.