Design of an Active Tunable Bandpass Filter for Spectrum Sensing Application in the TVWS Band

Kim, Dong–Su; Kim, Dohyun; Yun, Sang‐Won

doi:10.5515/jkiees.2017.17.1.34

Cited by 7 publications

(1 citation statement)

References 10 publications

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“…A switchable bandpass/bandstop filter has received particular attention as it enables radio systems to be operated in an interference-congested environment [1], reduces the size [2], solves the complexity problem [3], and reduces the cost [4,5,6,7]. For a dynamic interference situation, the bandpass/bandstop filters (BPF/BSF) are used in the bandstop mode to reduce the high-power interference close to the desired signal, while the bandpass filter is selected for a lower interference environment [8].…”

Section: Introductionmentioning

confidence: 99%

Switchable Bandpass/Bandstop Filter Using Liquid Metal Alloy as Fluidic Switch

Park

Lee

Lim

2019

Sensors

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In this paper, we propose a switchable band-pass/band-stop filter using liquid metal alloy as a fluidic switch. The filter is designed based on the Chebyshev response and implemented using a three-stage quarter-wavelength resonant structure. The fluidic switch is realized by injecting eutectic gallium–indium (EGaIn) in the microfluidic stubs, engraved in the polydimethylsiloxane (PDMS) material. When the fluidic switch selects the short stub using a micro-pump and microprocessor for switching, the filter acts as a bandpass filter (BPF) with the short stubs. When the fluidic switch selects the open stub, the filter acts as the bandstop filter (BSF) with the open stubs. At the BPF mode, the center frequency is 2.5 GHz and the 1-dB bandwidth is 1.75–3.07 GHz. The insertion loss is 0.5-dB ± 0.4-dB. At the BSF mode, the 15-dB bandstop bandwidth is 2.4–2.65 GHz with 2.5 GHz center frequency.

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Section: Introductionmentioning

confidence: 99%

Switchable Bandpass/Bandstop Filter Using Liquid Metal Alloy as Fluidic Switch

Park

Lee

Lim

2019

Sensors

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New method of analysis and design of frequency and bandwidth reconfigurable active filter

Sharma

Pandey

Tiwary

2018

Int J RF Microw Comput Aided Eng

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A new method of analysis and design of reconfigurable active bandpass filter is proposed. The proposed method involves matrix manipulation for equating passive inverter impedances with those of active inverter (both input and output impedances). Designing of active filter involves the designing of active inverter and active resonator. The filter performance is analysed in frequency range 500 MHz to 1.5 GHz. The narrow band filter is switched between two bands with varying fractional bandwidth and centre frequency. The physical implementation comprise elements employing ATF 21186 FET on RT Duroid 5880 substrate with dielectric constant 2.2 and thickness 0.127 mm. Active resonator comprises of an active capacitor and a passive inductor. The active inverter along with active resonator employed in active filter circuit provides reconfigurability in frequency (≈200 MHz) as well as in bandwidth with the variation in gain of approximately 8‐10 dB. The electrical performance of active band pass filter shows good agreement with the measured response. To best of my knowledge first time integration of active inverter and active capacitor is done. Intergration of such kind allows for frequency as well as bandwidth tuning. The electrical performance of active band pass filter shows slight deviation from with the measured response.

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