Compact lowpass filter with wide stop-band using coupled-line hairpin unit

Wei, Feng; Chen, L.; Shi, Xiaowei; Huang, Qiulin; Wang, X.-H.

doi:10.1049/el.2010.2411

Cited by 43 publications

(37 citation statements)

References 5 publications

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“…A microstrip LPF by using triangular and radial patch resonators is designed [9], but this filter suffers from gradual transition band. To design an LPF with wide stopband, a cascaded microstrip coupled-line hairpin unit and semicircle stepped-impedance shunt stubs are used in [10]. In [11], by employing LC resonant structures and transformed radial stubs, an LPF is proposed.…”

Section: Introductionmentioning

confidence: 99%

“…In [11], by employing LC resonant structures and transformed radial stubs, an LPF is proposed. However, the occupied areas of both circuits introduced in [10] and [11] are relatively large. Two other methods to design an LPF with sharp transition band use asymmetric high-low impedance patches and LC tank resonators, which are reported in [12] and [13], respectively.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

A Compact Microstrip Lowpass Filter With Sharp Roll-Off Rate and Ultra-Wide Stopband Employing Coupled Polygon Patches

Abdipour¹,

Abdipour²,

Lorestani³

2017

PIER C

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Abstract-In this paper, a microstrip lowpass filter with −3 dB cutoff frequency of 1.8 GHz composed of two resonators with different polygon patches and six symmetric suppressing cells is presented. To design the proposed filter, the impact of each microstrip transmission line on the scattering parameters of the employed resonators is separately determined by extracting the equations of the insertion loss (S 21 ) and return loss (S 11 ) on the basis of their equivalent LC circuit. The designed filter is fabricated and measured, and a good agreement between the results of simulation and measurement is obtained. In the whole stopband region, a return loss better than −0.35 dB and an acceptable suppression level of −22 dB from 1.87 to 19.75 GH are achieved. Furthermore, a flat insertion loss in the passband and an acceptable return loss (−19.32 dB) in this band can verify desired in-band performance. The designed lowpass filter has a high figure of merit about 36969.34.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

A Compact Microstrip Lowpass Filter With Sharp Roll-Off Rate and Ultra-Wide Stopband Employing Coupled Polygon Patches

Abdipour¹,

Abdipour²,

Lorestani³

2017

PIER C

View full text Add to dashboard Cite

show abstract

“…Another technique to design an LPF with sharp transition band uses asymmetric high-low impedance patches, which is reported in [10]. To design an LPF with wide stopband, a cascaded microstrip coupled-line hairpin unit and semi-circle stepped-impedance shunt stubs are used in [11]. In [12], by employing LC resonant structures and transformed radial stubs an LPF is proposed.…”

Section: Introductionmentioning

confidence: 99%

“…One more approach to design an LPF with sharp transition band uses LC tank resonators, which is reported in [13]. However, the occupied area of circuits, [11][12][13], are relatively large. In [14], a lowpass filter using polygon patch resonant cells, T-shaped resonators and two different suppressing cells is designed; however, this filter does not have a sharp transition band.…”

Section: Introductionmentioning

confidence: 99%

Compact Microstrip Lowpass Filter With High and Wide Rejection in the Stopband Utilizing Flabelliform Resonators

Abdipour¹,

Abdipour²

2017

PIER M

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Abstract-In this paper, a microstrip lowpass filter with −3 dB cutoff frequency of 3.8 GHz consisting of two cascaded resonators with flabelliform patches and two symmetric suppressing cells is proposed. To design the filter, the impact of each transmission line on the frequency response is determined by extracting the equations of the insertion loss (S 21 ) and return loss (S 11 ) on the basis of the equivalent LC circuit of the main resonance cell and the cascaded structure. The designed filter is constructed and tested, and a good agreement between the results of simulation and measurement is obtained. In the whole stopband region, a return loss close to zero and an acceptable suppression level of −30 dB from 4.47 to 25.17 GHz are achieved. Furthermore, a flat insertion loss in the passband and a low return loss (−23.02 dB) in this band can prove desired in-band and out-band frequency response.

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“…By the loaded SIRs, transmission zeros can be easily introduced and controlled to suppress the spurious responses. Defected ground structure (DGS) is also widely used in LPF design recently [7][8][9][10][11][12][13][14][15][16][17][18]. In [8], the LPF with cross-shape DGS shows a 20-dB suppression from 4.25 GHz to 15.9 GHz.…”

Section: Introductionmentioning

confidence: 99%

Design of Compact Lowpass Filter With Ultra-Wide Stopband Using Thin Slots

Wu¹,

Tseng²,

Tu³

2012

PIER C

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Abstract-This paper presents a compact microstrip steppedimpedance lowpass filter with ultra-wide stopband by using back-toback C-shaped and triple C-shaped thin slots. The properties of several thin slots in the ground plane have been investigated in this paper. With the full-wave simulation results and a simplified equivalent model, the total equivalent inductance of the thin slots can be extracted at cutoff frequency for lowpass filter design purpose. On the other hand, the thin slots work as bandstop filter at the stopband of the lowpass filter for a better stopband rejection. The proposed lowpass filter with a cutoff frequency of 2 GHz shows a wide stopband with an over 25-dB attenuation up to 17.5 GHz. From dc to 2 GHz, the insertion loss is less than 0.3 dB and the return loss is greater than 20 dB. In comparison to the conventional stepped-impedance lowpass filter with the same passband performance, the proposed lowpass filter shows not only a 24.3% size reduction but also a better stopband rejection.

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Compact lowpass filter with wide stop-band using coupled-line hairpin unit

Cited by 43 publications

References 5 publications

A Compact Microstrip Lowpass Filter With Sharp Roll-Off Rate and Ultra-Wide Stopband Employing Coupled Polygon Patches

A Compact Microstrip Lowpass Filter With Sharp Roll-Off Rate and Ultra-Wide Stopband Employing Coupled Polygon Patches

Compact Microstrip Lowpass Filter With High and Wide Rejection in the Stopband Utilizing Flabelliform Resonators

Design of Compact Lowpass Filter With Ultra-Wide Stopband Using Thin Slots

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