Acquisition performance of 2nd-order phase-locked loops in the presence of time delay for switched and swept signal conditions

Crompton (1966) and Develet (1963) performed detailed investigations of 1st- and 2nd-order phase-locked loop systems, respectively, incorporating time delay. The work of Develet is particularly important to receiver designers, since it deals solely with 2nd-order systems. In the present investigation, the work of Develet is extended for both type 1 and type 2 2nd-order phase-locked loops and the pull-in process of the loop examined as a function of time delay for both switched and swept input signal conditions. The excellent agreement obtained between theory and practice clearly shows that swept pull-in is a phenomenon distinct from switched pull-in.