Phase length Electrical length

in figure @ right, wave shown seen n=1.5 wavelengths long. wave crest @ beginning of graph, moving towards right, arrive @ end after time 1.5t. electrical length of segment said 1.5 wavelengths or, expressed phase angle, 540° (or 3π radians) n wavelengths corresponds φ = 360°•n (or φ = 2π•n radians). in radio frequency applications, when delay introduced due transmission line, phase shift φ of importance, specifying design in terms of phase or electrical length allows 1 adapt design arbitrary frequency employing wavelength λ applying frequency.