This letter introduces a novel calibration scheme designed for concurrent dual-band receivers based on a multiport interferometer aimed at resolving mismatches introduced by circuitry imperfections and distortion resulting from mutual interference. With mathematical deviations, we have demonstrated how these nonidealities degrade the performance of the receiver. In addition, we have shown that our proposed scheme has an affirmative impact on the mismatches and mutual interference between different input signals. With numerical investigations, the effectiveness of the proposed structure is validated, and a minimum of 36.2% and 66.7% improvement in error vector magnitude (EVM) is recorded compared with the reported literature under 0.2 and 2 Gb/s, respectively. In addition, a 15.6-dB improvement in the isolation between the dual-band signals is achieved.