You should use FIR filters to produce linear phase responses. Linear phase response implies that all frequencies in the system have the same propagation delay.
The following block diagram displays the frequency response of Equi-Ripple FIR filters. The diagram is similar to that used in Designing IIR Filters because the same mathematical theory applies to this type of filter.
The following graphs show the magnitude and phase response of a bandpass FIR filter.
The discontinuities in the phase are a result of using the absolute value of the magnitude. Still, it is linear response as described in Finite Impulse Response Filters.