IEEE Transactions on Automatic Control, Vol.50, No.12, 2021-2027, 2005
On the equivalence of three independently developed phase-locked loops
Three independent research groups have proposed three apparently different architectures for an improved phase-locked loop (PLL) structure through three entirely different approaches. It is shown that all three PLLs are structurally and mathematically the same. A linear analysis is performed and concludes that the available theory for the design of conventional PLLs can be leveraged into the design of the new class of PLLs.
Keywords:Costas loop;frequency estimation;phase detection;phase-locked loop (PLL);signal decomposition