Microwave Diffraction -W Band Lattice Scattering C. P. Yuan ( 袁景濱 ) 02/17/2009

Outline Introductions -Principle, and Motivation Plane Wave -Now and Before Diffraction -HFSS Simulation Conclusion

Motivation Use microwave source to do X-ray diffraction, so the lattices is observable. It is easier to study the phenomenon in a lattice structure.

Fourier Series

3D Fourier Series

3D Fourier Series (continued)

Lattice Diffraction Crystal specimen

Lattice Diffraction (continued)

Bragg diffraction (continued)

The wave is coherent and plane. The wave transits the whole lattices. Most of wave is transmissible for a lattice. Enough many lattices Enough far for the observer Hypotheses

Plane Wave Source CoaxialHorn

HFSS Plane Wave

Transmission in Materials dielectricconductor

Before and Now Before Now

Structure WR10   Freq. = 94 GHz 0.4 mm 1.27 mm 18 mm 6 mm d = 2.25 mm 6 cm

Transmission

Conclusion Use the horn structure can reduce the reflection. The dielectric materiel is more suitable than the conductor.

Reference Charles Kittel, “Introduction to Solid State Physics” Mark Cartwright, “Fourier Methods” Walter Rudin, “Principles of Mathematical Analysis” 欒丕網 陳啟昌 --- 光子晶體 F. Sporleder and H.-G. Unger, “Waveguide Tapers Transitions and Couplers” HFSS Simulator - Ansoft Corporation