This article addresses a discrete tunable resonator with three different states controlled by a single DC source. The passive components are designed together with the active elements, and both are integrated on a silicon substrate. This method of co-design offers great flexibility in doped area sizing and positioning, allowing for easy management of novel three-state resonators based on two different doped areas (or two different surfaces of semiconductor junctions). The largest area switches from the reverse state (OFF-state) to the forward state (ON1-state), with a lower bias voltage than the smallest area (ON2-state). This concept offers some new degrees of freedom in the design of tunable microwave devices, showcased in this study by a demonstrator that can operate at three different resonant frequencies. Good agreement was obtained between simulations and measurements in the three states. Insertion losses are lower than 1.6 dB and the same for the different states.