Frequency discriminator design phase formula with experimental verification for frequency measurement systems with uniform sub-band resolution

In this article, we propose a frequency discriminator (FD) design method to produce uniform frequency sub-bands. FDs are designed using an interferometer projected with the proposed formulated phase. For experimental verification that a uniform sub-band is formed using the proposed phase formula, 3-bit FDs are designed and fabricated to operate in the 2 to 3 GHz and 2 to 4 GHz bands, respectively. The FD consists of a power divider/combiner, reference line, and delay line. Scattering parameters of the FDs are analyzed using RF simulation and measurement results. RF characteristic results show that a 3-bit FD designed using the proposed phase formula can identify an unknown signal inside the defined frequency band.