• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.29 no.10
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• pp.739-744
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• 2018

In this paper, a double split-ring resonator(DSRR) is proposed to improve the isolation between Vivaldi antenna elements. The DSRR was designed using a unit cell simulation and applied to a $1{\times}2$ Vivaldi antenna array to confirm the improvement in the isolation. The unit cell size of the proposed DSRR is $5mm{\times}5mm{\times}1.52mm$ and six unit cells are used. To verify the performance of the proposed DSRR, $1{\times}2$ Vivaldi antenna arrays with and without the DSRR were fabricated and measured. The results show an isolation improvement of 20 dB in the Vivaldi antennas with the DSRR when compared to the Vivaldi antennas without the DSRR.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.2
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• pp.19-22
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• 2014

In this paper, Ku-band low phase noise oscillator using DSRR structure resonator based on metamaterial was proposed. To improve the phase noise of the oscillator, the proposed resonator consist of a DSRR strcuture based on metamaterial. The proposed resonator have a characteristic of $S_{11}$ is -0.25 dB, and $S_{21}$ in -44.59 dB at 14.67 GHz, respectively. At 14.67 GHz, the proposed Ku-band low phased oscillator achieves a output power of 2.03 dBm, $2^{nd}$ harmonic of -36.04 dBc, and phase noise of -130.63 dBc at the 100 kHz offset, respectively.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.45 no.8
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• pp.60-68
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• 2008

The complex permittivity and permeability of various periodic metamaterial (MTM) cells are extracted by simulating a fictitious rectangular waveguide consisting of PEC and PMC walls. The shapes of the MTM cells include a thin wire (TW), a single split-ring resonator (SSRR), a double SRR (DSRR), a modified SRR, and a combined structure of the TW and the DSRR. The TW falls on a negative-$\varepsilon$/positive-$\mu$ region, the SRRs on a positive-$\varepsilon$/negative-$\mu$ region, and the combined structure on a negative-$\varepsilon$/negative-$\mu$ region. We also investigate how the permeability and permeability are affected by the dimension parameters of the MTM cells. Another extraction technique utilizing time domain signals is developed overcoming some limitations that the waveguide technique can not handle.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.2
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• pp.194-201
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• 2010

We propose a frequency selective surface(FSS) using double split ring resonators(DSRRs) for isolation enhancement between CDMA and RFID. The structure consists of an outer SRR and an inner SRR, and the gaps are formed in the same direction. By properly adjusting the gap and line width, the resonant frequency and skirt characteristics can be adjusted without varying the unit cell size. The proposed structure has a different field distribution from that of an ordinary SRR for magneto-dielectric materials. One layer consists of $9{\times}9$ unit cells and the other layer was separated by 50 mm. To validate the simulation results, we fabricated the patch antenna and the FSSs, and the measured results show a good agreement with the simulated ones. The electrical size of the unit cell is $0.110\;{\lambda}{\times}0.110\;{\lambda}{\times}0.002\;{\lambda}$, and the size of the two layer FSS is $1.058\;{\lambda}{\times}1.058\;{\lambda}{\times}0.153\;{\lambda}$. The two layer FSS maintain gain in CDMA frequency and has 6.9 dB reduced gain in RFID frequency.