In order to suppress the time-delay signature (TDS) of the chaotic signals, a novel filtered optical feedback structure based on a semiconductor ring laser (SRL) is proposed. The fourth-order Runge-Kutta algorithm is used for simulating and the TDS of the chaotic signal output from a SRL is quantified by autocorrelation function and delay mutual information. The results show that, compared with the conventional optical feedback structure, the filtered optical feedback can effectively eliminate the TDS caused by the external cavity feedback delay time. Moreover, through calculating the distribution of autocorrelation and mutual information peaks in the parameter space of filter frequency detuning and filter bandwidth, it is found that TDS has been best concealed in the positive frequency detuning region.