  Complex weights factors (CWFs) that fully define the incident beam
independent of the presence of a scatterer, may be represented mathematically
by either a partial-wave series expansion (PWSE) of multipoles, or the method
of angular spectrum decomposition (ASD) of plane waves. Once the mathematical
expression for the CWFs of the incident waves is known, evaluation of the
arbitrary scattering, radiation force, and torque components on an object in
3D, using the Generalized Theories of Resonance Scattering (GTRS), Radiation
Force (GTRF) and Radiation Torque (GTRT), becomes feasible. The aim of this
Letter is to establish the connection between these two approaches in the
framework of the GTRS, GTRF and GTRT in spherical coordinates for various
acoustical applications. The advantage of using the ASD approach is also
discussed for specific beams with particular properties.
