Title :
A Reconfigurable Micromachined Switching Filter Using Periodic Structures
Author :
Karim, Muhammad Faeyz ; Liu, Ai-Qun ; Alphones, A. ; Yu, Aibin
Author_Institution :
Nanyang Technological University
fDate :
6/1/2007 12:00:00 AM
Abstract :
In this paper, a reconfigurable filter using micromachined switches is designed, fabricated, and experimented. An equivalent-circuit model is derived for the reconfigurable cell structure. Extracted parameters show the characteristics of both bandpass and bandstop filters, which can be accurately analyzed using circuit analysis. Coplanar waveguide transmission lines for the reconfigurable filter are also analyzed. The bandpass filter is formed by cascading the unit cell structure. This bandpass filter can be switched to bandstop filter using the micromachined switches and p-i-n diode. Dispersion characteristics are obtained to investigate the electromagnetic wave behavior within the unit cell using Floquet´s theorem. Measurement results with micromachined switches show that insertion loss is 1.55 dB for the bandpass filter whereas band rejection level is >20 dB and the insertion loss in the passband is 1.2 dB for the bandstop filter. With the p-i-n diode, the insertion loss is 2.1 dB and the 3-dB bandwidth is 5.2 GHz for the bandpass filter, the 20-dB rejection bandwidth is 5.3 GHz, and the insertion loss in the passband is 1.6 dB for the bandstop filter.
Keywords :
band-pass filters; band-stop filters; coplanar transmission lines; coplanar waveguides; dispersion (wave); equivalent circuits; losses; micromachining; microswitches; microwave filters; microwave switches; p-i-n diodes; periodic structures; switched filters; Floquet´s theorem; band rejection level; bandpass filter characteristics; bandstop filter characteristics; bandwidth 5.2 GHz; bandwidth 5.3 GHz; circuit analysis; coplanar waveguide transmission lines; dispersion characteristics; electromagnetic wave behavior; equivalent-circuit model; insertion loss; loss 1.2 dB; loss 1.55 dB; loss 1.6 dB; loss 2.1 dB; p-i-n diode; periodic structures; reconfigurable cell structure; reconfigurable micromachined switching filter; Band pass filters; Bandwidth; Circuit analysis; Coplanar waveguides; Electromagnetic waveguides; Insertion loss; P-i-n diodes; Passband; Periodic structures; Switches; Bandpass filter; bandstop filter; coplanar waveguide (CPW); reconfigurable filter;
Journal_Title :
Microwave Theory and Techniques, IEEE Transactions on
DOI :
10.1109/TMTT.2007.897670