A Design of Low-pass Filter with Wide Stopband and Sharp Roll-off Rate Using Series LC Tanks Resonator
Keywords:
High-low impedance lines, LC tank patches, Lowpass Filter (LPF)Abstract
In this letter, a lowpass filter (LPF) using resonators synthesized with series LC tank patches has been proposed. Each of the employed LC tank is composed of a high-low impedance lines, which have been mirrored to create the patches of the main resonance cells. Using this kind of resonator combining with eight suppressing cells leads to designing a LPF with specifications such as ultra-wide stopband, sharp cut-off and an acceptable return loss in the pass band. The -3 dB cut-off frequency of the proposed LPF is located in 2.4 GHz. The spurious frequencies have been suppressed in the stop-band region from 2.66 up to 23 GHz with a suppression level of -35 dB. Moreover, the transition band has been measured from 2.4 to 2.67 GHz with corresponding attenuation levels of -3 and -40 dB, respectively. To clarify the performance of each section and how they affect the frequency response the equivalent LC circuit of resonators and the final design have been obtained, separately.
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References
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