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Reconfigurable ring filter with controllable frequency response.

Ab Wahab N, Mohd Salleh MK, Ismail Khan Z, Abd Rashid NE - ScientificWorldJournal (2014)

Bottom Line: For demonstration, two prototypes of reconfigurable ring filters are realized using microstrip technology, simulated, and measured to validate the proposed concept.The reconfigured filter using lumped elements is successfully reconfigured from 2 GHz to 984.4 MHz and miniaturized by 71% compared to the filter directly designed at the same reconfigured frequency, while, for the filter using varactor-diodes, the frequency is chosen from 1.10 GHz to 1.38 GHz spreading over 280 MHz frequency range.Both designs are found to be compact with acceptable insertion loss and high selectivity.

View Article: PubMed Central - PubMed

Affiliation: Microwave Technology Centre, Faculty of Electrical Engineering, Universiti Teknologi MARA (UiTM), 40150 Shah Alam, Selangor, Malaysia.

ABSTRACT
Reconfigurable ring filter based on single-side-access ring topology is presented. Using capacitive tuning elements, the electrical length of the ring can be manipulated to shift the nominal center frequency to a desired position. A synthesis is developed to determine the values of the capacitive elements. To show the advantage of the synthesis, it is applied to the reconfigurable filter design using RF lumped capacitors. The concept is further explored by introducing varactor-diodes to continuously tune the center frequency of the ring filter. For demonstration, two prototypes of reconfigurable ring filters are realized using microstrip technology, simulated, and measured to validate the proposed concept. The reconfigured filter using lumped elements is successfully reconfigured from 2 GHz to 984.4 MHz and miniaturized by 71% compared to the filter directly designed at the same reconfigured frequency, while, for the filter using varactor-diodes, the frequency is chosen from 1.10 GHz to 1.38 GHz spreading over 280 MHz frequency range. Both designs are found to be compact with acceptable insertion loss and high selectivity.

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(a) Final layout of the reconfigurable ring bandpass filter; (b) fabricated photo.
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fig9: (a) Final layout of the reconfigurable ring bandpass filter; (b) fabricated photo.

Mentions: During implementation of the filter on microstrip substrate, once again the value of the reconfigured capacitor Cr needs to be adjusted. This is due to the effect of connecting pads (to connect the four lumped capacitors to the ring resonator), via holes, bonding wires, soldering, and the availability of the RF lumped capacitor value available in the market. Based on the calculation of Cr in the previous discussion, RF lumped capacitor with 2.2 pF is chosen. The final layout of the circuit is illustrated in Figure 9(a) with dimensions tabulated in Table 5.


Reconfigurable ring filter with controllable frequency response.

Ab Wahab N, Mohd Salleh MK, Ismail Khan Z, Abd Rashid NE - ScientificWorldJournal (2014)

(a) Final layout of the reconfigurable ring bandpass filter; (b) fabricated photo.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4121041&req=5

fig9: (a) Final layout of the reconfigurable ring bandpass filter; (b) fabricated photo.
Mentions: During implementation of the filter on microstrip substrate, once again the value of the reconfigured capacitor Cr needs to be adjusted. This is due to the effect of connecting pads (to connect the four lumped capacitors to the ring resonator), via holes, bonding wires, soldering, and the availability of the RF lumped capacitor value available in the market. Based on the calculation of Cr in the previous discussion, RF lumped capacitor with 2.2 pF is chosen. The final layout of the circuit is illustrated in Figure 9(a) with dimensions tabulated in Table 5.

Bottom Line: For demonstration, two prototypes of reconfigurable ring filters are realized using microstrip technology, simulated, and measured to validate the proposed concept.The reconfigured filter using lumped elements is successfully reconfigured from 2 GHz to 984.4 MHz and miniaturized by 71% compared to the filter directly designed at the same reconfigured frequency, while, for the filter using varactor-diodes, the frequency is chosen from 1.10 GHz to 1.38 GHz spreading over 280 MHz frequency range.Both designs are found to be compact with acceptable insertion loss and high selectivity.

View Article: PubMed Central - PubMed

Affiliation: Microwave Technology Centre, Faculty of Electrical Engineering, Universiti Teknologi MARA (UiTM), 40150 Shah Alam, Selangor, Malaysia.

ABSTRACT
Reconfigurable ring filter based on single-side-access ring topology is presented. Using capacitive tuning elements, the electrical length of the ring can be manipulated to shift the nominal center frequency to a desired position. A synthesis is developed to determine the values of the capacitive elements. To show the advantage of the synthesis, it is applied to the reconfigurable filter design using RF lumped capacitors. The concept is further explored by introducing varactor-diodes to continuously tune the center frequency of the ring filter. For demonstration, two prototypes of reconfigurable ring filters are realized using microstrip technology, simulated, and measured to validate the proposed concept. The reconfigured filter using lumped elements is successfully reconfigured from 2 GHz to 984.4 MHz and miniaturized by 71% compared to the filter directly designed at the same reconfigured frequency, while, for the filter using varactor-diodes, the frequency is chosen from 1.10 GHz to 1.38 GHz spreading over 280 MHz frequency range. Both designs are found to be compact with acceptable insertion loss and high selectivity.

Show MeSH