This paper starts with the characteristics and advantages of microwaves processing. The shortcomings of fixed frequency, typically at 2.45 GHz were also mentioned. On account of this, the newly developed variable frequency microwave (VFM) fabrication was mentioned and adopted in place of the fixed frequency process. Two cases of fixed frequency microwave processing of materials were described; the characteristics and pros of each case was mentioned and commented. Two cases of processing materials using variable frequency microwave facility (VFMF) were mentioned; the advantages and limitations of each case were discussed. The microwave processing of materials provides improved mechanical, physical and electrical properties with much reduced processing time. Furthermore, variable frequency microwave processing is more superior to its fixed frequency counterpart except that the cost of the facilities of the former is much higher than the latter at this point in time but it appears that the price will drop in the coming ten years.
2. Venkatesh, M. S. and G. S. V. Raghavan, "An overview of microwave processing and dielectric properties of agri-food materials," Biosystems Engineering, Vol. 88, No. 1, 1-18, 2004.
3. Thostenson, E. T. and T. W. Chou, "Microwave processing: Fundamentals and applications," Composites A, Vol. 30, 1055-1071, 1999.
4. Ku, H. S., E. Siores, and J. Ball, "Productivity improvement through the use of industrial microwave technologies," Journal of Computers and Industrial Engineering, Vol. 42/2-4, 281-290, 2002.
5. Lee, W. I. and G. S. Springer, "Microwave curing of composites," Journal of Composite Materials, Vol. 18, 387-409, 1984.
6. Metaxas, A. C. and R. J. Meredith, Industrial Microwave Heating, 5-6, 28-31, 43, 211, 217, 278, 284-285, Peter Peregrinus Ltd., 1983.
7. Liu, F., I. Turner, E. Siores, and P. Groombridge, "A numerical and experimental investigation of the microwave heating of polymer materials inside a ridge waveguide," Journal of Microwave Power and Electromagnetic Energy, Vol. 31, No. 2, 71-82, 1996.
8. Wei, J. B., K. Ngo, D. A. Tucker, Z. Fathi, F. L. Paulauskas, and W. G. Johanson, "Industrial processing via variable frequency microwaves part I: Bonding applications," Journal of Microwave Power and Electromagnetic Energy, Vol. 33, No. 1, 10-17, 1998.
9. Everleigh, C. A., A. C. Johnson, R. J. Espinosa, and R. S. Garard, "Use of high power travelling wave tubes as a microwave heating source," Material Research Society Symposium Proceeding, Vol. 347, 79-89, 1994.
10. Fathi, Z., R. S. Garard, M. T. DeMeuse, J. Clemens, and C. Saltiel, "Processing and modelling of select PMCs using variable frequency microwave irradiation," Polym. Mater. Sci. Eng., Vol. 72, 74-75, 1995.
11. Lu, Z., H. Ding, W. Sun, and P. Shi, "The study on experiment and mechanism of sterilization with electromagnetic wave," Journal of Electromagnetic Waves and Applications, Vol. 21, No. 6, 729-735, 2007.
12. Ku, H. S., E. Siores, and J. A. R. Ball, "Welding of thermoplastic composite using microwave energy," Proceedings of CIRP International Symposium — Advanced Design and Manufacturing in the Global Manufacturing Era, Vol. 2, 612-8, 1997.
13. Bolton, W., "Materials and Their Uses," Butterworth and Heinemann, 128, 1996.
14. Ku, H. S., V. Puttgunta, and M. Trada, "Young's modulus of vinyl ester composites cured by microwave irradiation: Preliminary results," Journal of Electromagnetic Waves and Applications, Vol. 20, No. 14, 1911-1924, 2006.
15. Ku, H. S., M. Trada, V. Puttgunta, and V. Kota, "Yield and tensile strength of vinyl ester composites cured by microwave," Journal of Electromagnetic Waves and Applications, Vol. 21, No. 4, 517-526, 2007.
16. Cardona, F., H. S. Ku, N. Pattarachaiyakoop, D. Rogers, and M. Trada, "Fracture toughness of phenol formaldehyde composites post-cured in microwave," Journal of Electromagnetic Waves and Applications, Vol. 21, No. 14, 2137-2146, 2007.
17. Schwartz, M. M., Composite Materials Handbook, 2nd Ed., 6.55-56, McGraw-Hill, USA, 1992.
18. Varadan, V. K. and V. V. Varadan, "Microwave joining and repair of composite materials," Polymer Engineering and Science, Vol. 3, No. 7, 470-486, 1991.
19. Schwartz, M. M., Joining of Composite-matrix Materials, 64, ASM International, USA, 1995.
20. Ku, H. S., E. Siores, and J. A. R. Ball, "Relationship between microwave irradiation and constituents of composites during joining process," Transactions, Vol. 7, No. 3, 41-49, 2000.
21. Ku, H. S., E. Siores, J. A. R. Ball, and M. MacRobert, "Variable frequency microwave processing of thermoplastic composites," Plastics, Rubber and Composites, Vol. 29, No. 8, 278-284, 2000.
22. Liu, Y., Y. Xiao, A. Sun, and D. A. Scola, "Microwave irradiation of nadic-end-capped polyimide resin (RP-46 resin) and glass-graphite-RP-46 composites: Cure and process study," Journal of Applied Polymer Science, Vol. 73, 2391-2411, 1999.
23. Ku, H. S., E. Siores, J. A. R. Ball, and B. Horsfiled, "Permittivity measurement of thermoplastic composites at elevated temperature," Journal of Microwave Power and Electromagnetic Energy, Vol. 36, No. 2, 101-111, 2001.
24. Ku, H. S., E. Siores, J. A. R. Ball, and M. MacRobert, "Characterization of thermoplastic composites using variable microwave facilities configuration," Plastics, Rubber and Composites, Vol. 29, No. 8, 285-287, 2000.
25. Tanikella, R. V., S. A. B. Allen, and P. A. Kohl, "Variable frequency microwave curing of Benzocyclobutene," Journal of Applied Polymer Science, Vol. 83, 3055-3067, 2002.
26. Lauren, K., et al., Multi-Chip Module Conference Proceedings, 229-231, IEEE, 1995.
27. Liu, H.-X., H. Zhai, L. Li, and C.-H. Liang, "A progressive numerical method combined with MON for a fast analysis of large waveguide slot antenna array," Journal of Electromagnetic Waves and Applications, Vol. 20, No. 2, 183-192, 2006.
28. Yau, D. and N. V. Shuley, "Numerical analysis of coupling between dielectric image guide and microstrip," Journal of Electromagnetic Waves and Applications, Vol. 20, No. 15, 2215-2230, 2006.
29. Habashy, T. M. and A. Abubakar, "A generalized material averaging formulation for modelling of the electromagnetic fields," Journal of Electromagnetic Waves and Applications, Vol. 21, No. 9, 1145-1159, 2007.
30. Engstrom, C. and D. Sjoberg, "On two numerical methods for homogenization of Maxwell's equations," Journal of Electromagnetic Waves and Applications, Vol. 21, No. 13, 1845-1856, 2007.
31. Hatamzadeh-Varmazyar, S. and M. Naser-Moghadasi, "New numerical method for determining the scattered electromagnetic fields from thin wire," Progress In Electromagnetics Research B, Vol. 3, 207-218, 2008.
32. Suyama, T., Y. Okuno, A. Matsushima, and M. Ohtsu, "A numerical analysis of stop band characteristics by multilayered dielectric gratings with sinusoidal profile," Progress In Electromagnetics Research B, Vol. 2, 83-102, 2008.
33. Steinbauer, M., R. Kubasek, and K. Bartusek, "Numerical method of simulation of material influences in MR tomography," Progress In Electromagnetics Research Letters, Vol. 1, 205-210, 2008.