• Journal of electromagnetic engineering and science
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• v.15 no.1
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• pp.31-36
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• 2015

The design of a new compact band-pass filter is proposed, which is based on the microstrip composite right- and left-handed transmission- line (CRLH-TL) structure. Particularly, the interdigital coupled (IDC) lines of the CRLH geometry are proposed to be parted by inserting open stubs to meet the specifications on the passband. In addition, there is another pair of stubs to complete the design in a limited space. These are considered in the TL-based analysis and the design parameters are calculated by genetic algorithm optimization. The measurement is shown to be acceptable and agreeable with the circuit and electromagnetic field simulations. In addition, the zerothorder resonance (ZOR) phenomenon is verified.

• Journal of Electrical Engineering and Technology
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• v.9 no.3
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• pp.997-1001
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• 2014

In this paper, the interference in small MIMO antennas having two identical composite right- and left-handed transmission-line(CRLH-TL)-based radiating elements is remarkably decreased. The radiating element has the broadside-capacitive coupling as well as slots to be equivalent to the CRLH-TL to prevent the size from increasing for an LTE high band. The suspended line bridging the two radiating elements is optimized to lower the interference between them down to -23 dB, while the overall MIMO antenna system is compact and its antenna performance is acceptable. The design is tested for 2.5 GHz.

• Journal of IKEEE
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• v.22 no.4
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• pp.1050-1055
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• 2018

In this paper, we analyzed the sensitivity of matching elements for the dual-band operation of a power amplifier with composite right/left-handed (CRLH) transmission lines. Metamaterial theory enables CRLH transmission to support arbitrary impedance matching at dual frequencies. In general, at sub-GHz range, the CRLH matching networks are commonly implemented with lumped elements, which are prone to manufacturing distribution. In order to reduce the effect from the distribution of element values in design, we suggest a method to analyze the sensitivity of matching elements from the performance aspect of power amplifiers. Based on the analysis, a 40dBm dual-band power amplifier operating at 0.7GHz and 1.5GHz is designed.

• Journal of Electrical Engineering and Technology
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• v.8 no.5
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• pp.1152-1156
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• 2013

We propose a compact high-order(9th) UHF bandpass filter comprising the composite right-handed and left-handed(CRLH) zeroth-order resonators(ZORs) in the form of the three cascaded-triplets(CTs) newly applied to the ZOR filter which results in very steep skirt. The method is verified by circuit and EM simulations and measurement with metamaterial properties.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.8
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• pp.837-843
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• 2008

This paper proposes a power divider based on meta-material structure with dual-band operation. The meta-material structures of left-hand characteristic are constituted of series capacitors and shunt inductors, but they have parasitic series inductance and shunt capacitance effects. There is represented the composite right/ left-handed transmission line (CRLH-TL) model. When the power divider is implemented by using the CRLH-TL, the power divider can operate dual band. To verify the power divider with dual band, we are implemented to operate dual-band that is 0.88 GHz and 1.67 GHz. The characteristics of divider have the return loss less than each 21.0 dB and 15.8 dB and the insertion loss better than 3.83 dB and 3.64 dB at each frequency. Also, the output phase difference is $3{\sim}6^{\circ}$.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.47 no.1
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• pp.84-90
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• 2010

In this paper, a novel voltage-controlled oscillator (VCO) using the harmonic control circuit based on the composite right/left-handed (CRLH) transmission lines (TLs) is presented to reduce the phase noise without the reduction of the frequency tuning range and miniaturize the circuit size. The phase noise is reduced by the novel harmonic control circuit having the short impedances for the second- and third-harmonic components. The proposed harmonic control circuit is designed by using the CRLH TLs with the dual-band characteristic by the frequency offset and phase slope of the CRLH TLs. The high-Q resonator has been used to reduce the phase noise, but has the problem of the frequency tuning range reduction. However, the frequency tuning range of the proposed VCO has not been reduced because the phase noise has been reduced without the high-Q resonator. The miniaturization of the circuit size is achieved by using the CRLH TLs instead of the conventional right-handed (RH) TLs. The phase noise of VCO is -119.17 ~ -117.50 dBc/Hz at 100 kHz in the tuning range of 5.731 ~ 5.938 GHz.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.12
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• pp.1462-1469
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• 2008

This paper proposes the design method based on the Composite Right/Left-Handed(CRLH) structure to miniaturize and enhance the rejection performance in the stopband of the bandpass filter for a VHF band($169{\sim}211\;MHz$). For realization, we used the 0-th order resonance point of the CRLH and the simple theory of Inverter as coupling. The proposed technique is validated by the performance predictions and experiments, (Insertion loss <2 dB, $S_{11}$< -15 dB, suppression of up to the 3rd harmonic) and it is found out that the suggested method enables the size reduction of around 60 % from the conventional filters such as the parallel edge coupled type.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.47 no.5
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• pp.69-74
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• 2010

In this paper, we proposed a compact arbitrary dual-band band-stop filter using CRLH transmission line. The proposed filter used CRLH transmission line as stub and it developed dual-band band-stop characteristics using non-linear phase response of CRLH transmission line. The size of proposed filter is compact. And it can control arbitrary dual stop band. In this paper, designed band-stop filter at GPS band and ISM band As result, the S(2,1) is about -30dB at GPS band and about -29dB at ISM band. The fabricated filter is very compact. Its dimension is 10mm*15mm.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.3 no.2
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• pp.39-45
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• 2010

In this paper, an equally spaced $3{\times}2$ microstrip patch array antenna based on the fundamental infinite wavelength supported by the composite right/left-handed (CRLH) transmission line (TL) is proposed. The proposed CRLH TL unit cell consists of an inter-digit capacitor to realize left-handed (LH) series capacitance and non-symmetric shunt meander line with a shorted via to realize LH shunt inductance. At the infinite wavelength frequency of 2.09 GHz a 6-port series power divider consisting of a 19 unit cells shows a maximum magnitude difference of 0.73 dB and a $0.52^{\circ}$ maximum phase difference between output ports. The measured resonant frequency and maximum gain of the fabricated array antenna is 2.09 GHz and 10.98 dBi, respectively.

• ETRI Journal
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• v.36 no.1
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• pp.151-154
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• 2014

A novel frequency-switchable antenna that uses PIN diodes and a composite right- and left-handed transmission line (CRLH TL) is proposed. The CRLH TL provides multi-order resonance, including a zeroth-order resonance (ZOR), and its shunt stub determines the ZOR frequency. Thus, the resonant frequency is arbitrarily chosen by lumped chip inductors on the shunt stub. Two prototypes are designed using different chip inductors while maintaining the antenna geometries. Antenna #1 can switch the resonant frequency from 1.8 GHz to 2.3 GHz. Antenna #2 can switch its resonance from 0.9 GHz to 2.3 GHz.