The adaptive fiber-optics collimator (AFOC) is a kind of passive fiber-optics device with the capability of fast and precise tip-tilt deviation control of collimated output. With the rapid extension of its application areas, the AFOC with greater resonance characteristic is needed. A method of using step-profile damping structure to improve the resonance characteristic of AFOC is experimentally studied, and the results reveal that the first-order resonance frequency increases with the reduction of the first-order resonance peak. On this basis, a way to enhance the available bandwidth of AFOC is studied theoretically and experimentally based on the biquad digital filter technique. Experimental results show that the first-order resonance peak of AFOC is suppressed efficiently and the usable operation bandwidth increases from about 1.3 kHz to 2.5 kHz.