Frequency detection method with transversal filters

This paper presents a novel frequency detection method using transversal filters to generate new intermediate signals that are amplitude modulated in-phase and quadrature signals. By mutual calculations using the intermediate signals, amplitude modulation is cancelled out and a tangent signal includes phase of the input signal can be obtained. Measurement results show good frequency detection error of 8.7e-4 to 3.2e-1 without the input filter, and 2.0e-5 to 2.4e-3 with the input filter. 4 sampling time is required for a frequency detection without the input filter and 40 sampling required with the input filter.