A novel approach to the design of I/Q demodulation filters

A novel filter design approach to digital /Q (in-phase/quadrature) demodulation is proposed. This approach consists of two methods, i.e., a high-pass filter method suitable for B<f₀ and a new low pass filter method which is suitable for B<2f_o, where B is the IF (intermediate frequency) signal bandwidth and f_o is the carrier frequency. It maintains the advantages of the earlier method, such as zero DC offset, matched two-channel filter responses, and good performance over a wide bandwidth. The new methods possess higher computational efficiency than other approaches