This paper proposes a nonlinear filter-based model with low complexity for concurrent dual-band digital predistortion. The model saves remarkable number of multiplication and needs low precision of calculation, and can be easily realized on hardware platforms. Moreover, this model achieves almost the same linearization performance as the 2D-DPD model. A broadband GaN HEMT power amplifier is used to verify the model. The dual 20MHz band signal with 8 dB PAPR spacing 140MHz are tested at 2.55GHz. The proposed model uses only 18 complex multiplexers. With predistortion, ACPR can be improved from −38dBc to −50dBc.