A reconfigurable dual-passband to single-passband filter based on highly miniaturized ring resonators is presented. The filter is designed for 448 MHz for the first band and 668 MHz for the second band as the central passband frequencies and simulations are used for enhancing the design. The filter is implemented using microstrip technology on a RO3010 substrate with thickness of 1.28 mm. The lower passband can be eliminated by just changing the location of a short. Measurements for the optional eliminated band are in good agreement with the expected values. The transmission is −3  dB at the central frequency for dual-passband configuration and −26  dB for single-passband configuration.