Microwave CSIW Filter Based on The High Anisotropy Electro-Optic Nematic Liquid Crystal

Liu, Yupeng; Jiang, Di; Li, Xiaoyü; Wang, Zhen; Ran, Puhang; Fu, Zihao

doi:10.1109/icmmt45702.2019.8992079

Cited by 3 publications

(3 citation statements)

References 9 publications

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“…A comparison table is tabulated in Table 5. They provide less fabrication cost and complexity than [19,20] and less insertion loss than [16]. The fabrication cost is low because the rows of metallic vias (platted through hole) are replaced with the quarter wave open stub.…”

Section: Prototype Realizationmentioning

confidence: 99%

See 1 more Smart Citation

Corrugated Siw Based Bandpass Filter for Microwave Interferometer and Ism Band Application

Vala¹,

Patel²,

Mahant³

et al. 2021

PIER C

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A corrugated substrate integrated waveguide (CSIW) based bandpass filter is designed and developed for the microwave interferometer (7.0 GHz) and ISM band (5.7 GHz-5.9 GHz) application. CSIW structure provides a cost-effective solution counter to substrate integrated waveguide (SIW). Initially, the CSIW structure is designed from the design methodology of SIW. Vias are replaced with a quarter wavelength open stub. A metallic inductive post is used for the realization of the bandpass filter from the CSIW structure. Computer simulation technology (CST) software is used for design and simulation of the proposed model. Two structures are implemented for the microwave interferometer and ISM band frequency application. The first structure resonates at the center frequency of 7.023 GHz with the fractional bandwidth of 5.26%. It provides an insertion loss value of less than 1.5 dB and a return loss better than 14 dB. Similarly, the second structure provides passband frequency, from 5.6 GHz to 6.0 GHz, with the insertion loss value less than 1.5 dB and return loss better than 18 dB at the center frequency. It can be used for the ISM band frequency application. The frequency tuning approach is also shown to change the resonance frequency for different applications. For the proof of concept, the proposed filter is fabricated and tested. The measured results are quite similar to the simulation results.

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Section: Prototype Realizationmentioning

confidence: 99%

“…It is used for a beam scanning application at a fixed frequency of operation. A tunable bandpass filter using liquid crystal CSIW is given in [16]. A wideband bandpass filter in the frequency range of 12 GHz to 18 GHz with a periodic structure in the CSIW structure is shown in [17].…”

Section: Introductionmentioning

confidence: 99%

Corrugated Siw Based Bandpass Filter for Microwave Interferometer and Ism Band Application

Vala¹,

Patel²,

Mahant³

et al. 2021

PIER C

View full text Add to dashboard Cite

show abstract

“…Additionally, LCs need an especially low bias voltage compared to other tunable materials like ferrites or other devices like MEMS. For these reasons, the development of reconfigurable LC-based devices for MW or mmW applications has gotten the attention of the research community in recent years, and several reconfigurable LC devices such as steerable antennas [5], phase shifters [6][7][8][9][10], and filters [11][12][13][14][15][16] have been reported in the literature.…”

Section: Introductionmentioning

confidence: 99%

Characterization of Nematic Liquid Crystals at Microwave Frequencies

et al. 2020

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The use of nematic liquid crystal (LC) mixtures for microwave frequency applications presents a fundamental drawback: many of these mixtures have not been properly characterized at these frequencies, and researchers do not have an a priori clear idea of which behavior they can expect. This work is focused on developing a new procedure for the extraction of the main parameters of a nematic liquid crystal: dielectric permittivity and loss tangent at 11 GHz under different polarization voltages; splay elastic constant K11, which allows calculation of the threshold voltage (Vth); and rotational viscosity γ11, which allows calculating the response time of any arbitrary device. These properties will be calculated by using a resonator-based method, which is implemented with a new topology of substrate integrated transmission line. The LC molecules should be rotated (polarized) by applying an electric field in order to extract the characteristic parameters; thus, the transmission line needs to have two conductors and low electric losses in order to preserve the integrity of the measurements. This method was applied to a well-known liquid crystal mixture (GT3-23002 from MERCK) obtaining the permittivity and loss tangent versus bias voltage curves, the splay elastic constant, and the rotational viscosity of the mixture. The results validate the viability of the proposed method.

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Development of Reconfigurable High-Frequency Devices Using Liquid Crystal in Substrate-Integrated Gap Waveguide Technology

Voronov,

Bachiller,

Villacampa

et al. 2024

Crystals

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This article presents the theoretical study, numerical simulation and fabrication of a phase shifter and a stub resonator for use in microstrip ridge gap waveguide (MRGW) technology, using a liquid crystal (LC) in the substrate as a reconfigurable material. The phase shifter and the stub resonator are filled with LC, and thanks to the LC’s dielectric anisotropy properties, the phase shift and the resonance response can be easily controlled using an external electric or magnetic bias field. The phase shifter was designed to operate in the range of 10 to 20 GHz, and the resonator was designed to operate in the range of 7.8 to 8.8 GHz. The phase shifter’s responses (including both phase shift and insertion losses), associated with both the parallel and perpendicular permittivity values of the LC, were computed and measured, and then the corresponding figure of merit (FoM) was extracted. The resonator’s frequency responses, associated with both the LC’s parallel and perpendicular permittivity, were computed. The resonator’s frequency responses, which provided different polarization voltages, were measured and compared to the simulation results. All technological issues related to both prototypes are also discussed here. The good agreement between the simulation and measurement results confirm this technology as a viable approach to the practical implementation of these microwave reconfigurable devices.

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Microwave CSIW Filter Based on The High Anisotropy Electro-Optic Nematic Liquid Crystal

Cited by 3 publications

References 9 publications

Corrugated Siw Based Bandpass Filter for Microwave Interferometer and Ism Band Application

Corrugated Siw Based Bandpass Filter for Microwave Interferometer and Ism Band Application

Characterization of Nematic Liquid Crystals at Microwave Frequencies

Development of Reconfigurable High-Frequency Devices Using Liquid Crystal in Substrate-Integrated Gap Waveguide Technology

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