Title :
Micromachined filters on synthesized substrates
Author :
Drayton, Rhonda Franklin ; Pacheco, Sergio Palma ; Katehi, Linda P B ; Wang, Jianei ; Yook, Jong-Gwan
Author_Institution :
Dept. of Electr. Eng., Minnesota Univ., Minneapolis, MN, USA
fDate :
2/1/2001 12:00:00 AM
Abstract :
Effective high-frequency spectrum usage requires high-performance filters to have a sharp cutoff frequency and high stopband attenuation. Stepped-impedance low-pass designs achieve this function best with large ratios of high-to-low-impedance values. In high-index materials, such as Si (11.7) and GaAs (12.9), however these high-to-low-impedance ratios are around five, thereby significantly limiting optimum filter performance. This paper characterizes the use of Si micromachining for the development of synthesized substrates, which, when utilized appropriately, can further reduce the low-impedance value or increase the high-impedance value. Both designs have demonstrated high-to-low-impedance ratios that are 1.5-2 times larger than conventional techniques
Keywords :
Butterworth filters; Chebyshev filters; elemental semiconductors; low-pass filters; micromachining; microstrip filters; microstrip lines; silicon; Si; cutoff frequency; high-to-low-impedance value ratios; micromachined filters; optimum filter performance; stepped-impedance low-pass design; stopband attenuation; synthesized substrates; Attenuation; Circuit synthesis; Frequency; Gallium arsenide; Impedance; Low pass filters; Micromachining; Semiconductor materials; Silicon; Substrates;
Journal_Title :
Microwave Theory and Techniques, IEEE Transactions on
