# Translations:Dictionary:Phase characteristics/2/en

Any wavelet may be represented as the convolution of doublets and a wavelet is minimum phase if all of its doublet factors are minimum phase. For example, the *z*-transform of a wavelet might be (6+*z*–*z*^{2}), which can be expressed as (3–*z*)(2+*z*), each of which is minimum phase; hence the wavelet is minimum phase. Minimum phase is sometimes expressed as having all roots outside the unit circle in the *z*-plane, or as having no zeros in the right half of the Laplace transform *S*-plane. A **maximum-phase** or **maximum-delay** doublet [*a,b*] has |*a*|<|*b*|. Maximum-phase wavelets have all their roots inside the unit circle in the *z*-plane. For a **linear-phase** wavelet, the phase-frequency plot is linear. If its intercept is *n*π (where *n* is any integer), such a wavelet is symmetrical.