CCAST, World Lab, Beijing 100080, Peoples R China
; Chinese Acad Sci, Inst High Energy Phys, Beijing 100049, Peoples R China
; Chinese Acad Sci, Grad Sch, Beijing 100049, Peoples R China
; Univ Pittsburgh, Dept Phys & Astron, Pittsburgh, PA 15260 USA
; Univ Helsinki, Helsinki Inst Phys, FIN-00014 Helsinki, Finland
; Univ Helsinki, Dept Phys Sci, FIN-00014 Helsinki, Finland
The electromagnetic form factors, charge radii and decay constants of pi, K and K*(892) are calculated using the three forms of relativistic kinematics: instant form, point form and (light) front form. Simple representations of the mass operator together with single-quark currents are employed with all the forms. Making use of previously fixed parameters, together with the constituent-quark mass for the strange quark, a reasonable reproduction of the available data for form factors, charge radii and decay constants of pi, p, K and K*(892) is obtained in front form. With the instant form a similar description, but with a systematic underestimation of the vector meson decay constants is obtained using two different sets of parameters, one for pi and p and another one for K and K*(892). The point form produces a poor description of the data.