A novel planar dual-mode bandpass filter with double-comer cuts was proposed on the basis of traditional square patch dual-mode filter. The proposed structure has single patch resonator without coupling gaps, and two attenuation poles can be implemented on both sides of passband. The filter can also provide a low loss. An improved novel dual-mode elliptic-function passband filter with a pair of unequal crossed slots was also proposed. The return loss of this filter is 31.53dB at the center frequency of 1.8GHz, and the minimum insertion loss in passband is O. OldB, and the 3dB relative bandwidth is 19.44%. The results show that this filter can reduce loss effectively, and its size is reduced about 40% compared with the traditional filter. It makes miniaturization easy. The bandwidth is also greatly increased. The proposed filters are simulated by Ansoft Ensemble 8.0 software.