Desensitized Half-Band Filters

A common component in digital circuitry for communication systems is the half-band filter. Digital half-band filters are often used in cooperation with upsamplers and downsamplers in multirate systems when a sampling-rate change is required. While techniques for designing these filters are well known, an entirely new method for the design and implementation of lowpass FIR half-band filters is presented in this paper, one in which the filter's frequency response can be provided with a significant insensitivity to the filter's tap-coefficient values. Such insensitivity can be exploited in the filter-design process to yield half-band filters with reduced hardware requirements, which can lead to circuits having lower power consumption, higher operating speeds, and smaller IC area.