The paper presents theory, modeling, and analysis of a novel electrodynamic concentration approach for submillimeter-sized conductive metal particles focusing in moving gas-powder stream. Such method is of particular interest in blown-powder feeding fabrication industry (e.g., powder-fed additive manufacturing) to generate a tightly focused powder stream. Conceptual design of a concentration generator is proposed with two different configurations: The doublet Halbach permanent magnet quadrupoles (doublet-Halbach-PMQs) and the doublet electromagnet quadrupoles (doublet-EMQs). Analytical models for magnetic forces and concentration angles were built. Numerical calculations were conducted for pure aluminum particles with a radius of <math xmlns='http://www.w3.org/1998/Math/MathML'> <mrow> <mn>50</mn><mo><</mo><msub> <mi>R</mi> <mi>p</mi> </msub> <mo>≤</mo><mn>500</mn><mtext> </mtext><mi>μ</mi><mi>m</mi></mrow> </math>. It was found that the magnetic force and the concentration angle increase with an increase of the particle size. The numerical results indicate that the proposed concentration generator with doublet-Halbach-PMQs configuration cannot be effectively used for small-size particle concentration. By contrast, the concentration generator with doublet-EMQs configuration under high frequency is capable to concentrate particles with a radius of <math xmlns='http://www.w3.org/1998/Math/MathML'> <mrow> <msub> <mi>R</mi> <mi>p</mi> </msub> <mo>></mo><mn>150</mn><mtext> </mtext><mi>μ</mi><mi>m</mi></mrow> </math>. The particles with a radius of <math xmlns='http://www.w3.org/1998/Math/MathML'> <mrow> <msub> <mi>R</mi>