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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.

Show MeSH
Final responses on microstrip for reconfigurable filter using four capacitors: (a) simulated and measured S11; (b) simulated and measured S12.
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fig10: Final responses on microstrip for reconfigurable filter using four capacitors: (a) simulated and measured S11; (b) simulated and measured S12.

Mentions: The simulated and measured frequency responses are depicted in Figures 10(a) and 10(b), respectively. As observed, the simulated reconfigured center frequency attenuates at 0.985 GHz with return loss of 16.72 dB and insertion loss of 2.05 dB. Two transmissions zeros are found at 921 MHz and 1.09 GHz with fractional bandwidth of 1.73%. The measurement results show that the reconfigured center frequency falls at 0.984 GHz and attenuates at 20.78 dB level with insertion loss about 3 dB, while the two transmission zeros are found at 949.4 MHz and 1.104 GHz with fractional bandwidth of 2.03%.


Reconfigurable ring filter with controllable frequency response.

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

Final responses on microstrip for reconfigurable filter using four capacitors: (a) simulated and measured S11; (b) simulated and measured S12.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

fig10: Final responses on microstrip for reconfigurable filter using four capacitors: (a) simulated and measured S11; (b) simulated and measured S12.
Mentions: The simulated and measured frequency responses are depicted in Figures 10(a) and 10(b), respectively. As observed, the simulated reconfigured center frequency attenuates at 0.985 GHz with return loss of 16.72 dB and insertion loss of 2.05 dB. Two transmissions zeros are found at 921 MHz and 1.09 GHz with fractional bandwidth of 1.73%. The measurement results show that the reconfigured center frequency falls at 0.984 GHz and attenuates at 20.78 dB level with insertion loss about 3 dB, while the two transmission zeros are found at 949.4 MHz and 1.104 GHz with fractional bandwidth of 2.03%.

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