The spectral region of midinfrared has proven its great potential in various fields, such as materials characterization, medical examination, security, and product inspection. However, the development of room-temperature sensitive midinfrared photodetectors is inevitably in strong demand. Graphene-based detectors are expected to potentially overcome many of the shortcomings of earlier detectors. Unfortunately, low light absorption originating from a single atomic layer is still an obstacle for sensitive sensing using graphene-based photodetectors. To optimize the performance of plasmonic antenna, we have proposed wideband bull’s-eye-shaped antennas using cavity-mode resonance for the midinfrared region. The proposed multi-resonant frequency plasmonic antennas are integrated with graphene-based detectors for midinfrared detection. We demonstrated that the graphene device integrated with the multifrequency plasmonic antenna enabled the room-temperature sensitive midinfrared detection. In addition, such a device can achieve frequency filtering measurement through the bull’s eye shaped plasmonic antenna. The coupling of antenna onto the device largely spares the integration space. We believe that such a device is practical in various applications that require room-temperature, frequency selective sensitive photo detection.