• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.11
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• pp.60-66
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• 2007

In this paper, a novel voltage-controlled oscillator (VCO) using the microstrip square open loop multiple split ring resonator (OLMSRR) is presented for reducing the phase noise property. The square-shaped multiple split ring resonator (MSRR) having the form of the microstrip square open loop is investigated to realize this property. Compared with the microstrip square open loop resonator and the microstrip square open loop split ring resonator (OLSRR) as well as the conventional microstrip line resonator, the microstrip square OLMSRR has the larger coupling coefficient value, which makes a higher Q value, and has reduced the phase noise of VCO. The VCO with 1.7V power suppIy has the phase noise of $-124.5\;{\sim}\;-122.0\;dBc/Hz$ @ 100 kHz in the tuning range, $5.746\;{\sim}\;5.84\;GHz$. The figure of merit (FOM) of this VCO is $-203.96\;{\sim}\;-201.6\;dBc/Hz$ @ 100 kHz in the same tuning range. Compared with VCO using the conventional microstrip line resonator, VCO using the microstrip square open loop resonator and VCO using microstrip square OLSRR, the phase noise property of VCO using the proposed resonator has been improved in 25.66 dB, 8.34 dB, and 4.5 dB, respectively.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.12
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• pp.22-27
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• 2007

In this paper, a novel voltage-controlled oscillator (VCO) using the microstrip square open loop split ring resonator (OLSRR) is presented for reducing the phase noise. For this purpose, the square-shaped split ring resonator (SRR) haying the form of the microstrip square open loop is investigated. Compared with the microstrip square open loop resonator, the microstrip square OLSRR has the larger coupling coefficient value, which makes a higher Q value, and has reduced the phase noise of VCO. The VCO with 1.7V power supply has the phase noise of $-120\sim-116.5$ dBc/Hz @ 100 kHz in the tuning range, $5.746\sim5.854$ GHz. The figure of merit (FOM) of this VCO is $-200.33\sim-197$ dBc/Hz @ 100 kHz in the same tuning range.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.47 no.12
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• pp.84-89
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• 2010

In this paper, a novel voltage-controlled oscillator (VCO) using the microstrip square open loop dual split ring resonator is presented for reducing the phase noise. The square-shaped dual split ring resonator having the form of the microstrip square open loop is investigated to reduce the phase noise. Compared with the microstrip square open loop resonator and the microstrip square open loop split ring resonator as well as the conventional microstrip line resonator, the microstrip square dual split ring resonator has the larger coupling coefficient value, which makes a higher Q value, and has reduced the phase noise of VCO. The VCO with 1.7V power supply has the phase noise of -123.2~-122.0 dBc/Hz @ 100 kHz in the tuning range, 11.74~11.75 GHz. The figure of merit (FOM) of this VCO is-214.8~-221.7 dBc/Hz dBc/Hz @ 100 kHz in the same tuning range. Compared with VCO using the conventional microstrip line resonator, VCO using microstrip square open loop resonator, the phase noise of VCO using the proposed resonator has been improved in 26 dB, 10 dB, respectively.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.2
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• pp.245-251
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• 2011

In this paper, dual-band bandpass filter by using Pseudo-Interdigital Stepped-Impedance Resonator(PI-SIR) and Open-Loop Ring Resonator(OLRR) is proposed. The first passband and second passband are formed by PI-SIR and the second passband is reinforced by an OLRR. In a PI-SIR the first band and second band are easily and exactly adjusted by characteristic impedance ratio and electrical length ratio. The proposed design method may be confirmed to be useful from fabricated and measured results for dual-band bandpass filter operated at 2.45 GHz and 5.8 GHz.

• ETRI Journal
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• v.33 no.2
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• pp.291-294
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• 2011

This letter proposes an open-ended waveguide antenna with a single split-ring resonator. In contrast to the waveguide antennas incorporating multiple rings reported in a previous study, which exhibited narrow bandwidth, the proposed antenna uses only one ring to achieve broader bandwidth while keeping the aperture small. A single ring has a relatively low quality factor compared to multiple rings. The simulated and measured fractional bandwidth was 4.13% and 4.03%, respectively, which is much broader than the fractional bandwidth of about 1% demonstrated in a previous study. This simple technique can be used in many applications that require small apertures including near-field probes and array elements.

• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.10
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• pp.1175-1180
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• 2014

In this paper, the open ring type DGS(Defected Ground Structure) resonator, applicable to MMIC(Monolithic Microwave Integrated Circuit), is proposed to improve phase noise characteristics of RF oscillator. This resonator is planar type, therefore, it easy to design miniaturrized., and takes relatively high Q value. Modeling the equivalent parameter of resonator is needed, when designing the RF oscillator with resonator. The mathematical method to solve the equivalent parameter of the resonator from the measured results of resonator is introduced in this paper. To verify the method, DGS resonator with 5.8 GHz center frequency is fabricated, for measuring characteristics and calculating the equivalent parameter. The result from this process is compared with the data of the ADS simulation, and as a result both were identical.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.18 no.6 s.121
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• pp.674-679
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• 2007

In this paper, the size of the dual-mode microstrip ring resonator is reduced by adding four open stubs, and bandpass filters having 100 MHz bandwidth are designed at the center frequency of 2 GHz. The size of the ring resonator can be controlled by varying the capacitance of the stubs, and the bandpass filter can be designed in two cases, which are two combinations of the stubs. Two bandpass filters are designed and fabricated by using the two-stage bandpass filter circuit model of the proposed structure, and the measured results show good agreement with the simulated results.

• Journal of electromagnetic engineering and science
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• v.11 no.4
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• pp.235-238
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• 2011

In this paper, a novel low phase noise voltage-controlled oscillator (VCO) using metamaterial structure and rat race coupler is presented for reducing the phase noise without the reduction of the frequency tuning range. The metamaterial structure has been realized by microstrip square open loop double split ring resonator (SRR). The rat race coupler shows slightly higher transmission compared to a Wilkinson combiner and is, therefore, used instead to improve the performances of VCO. By providing these unique modifications, the proposed push-push VCO has a phase noise of -126.30~-124.83 dBc/Hz at 100 kHz in the tuning range of 5.672~5.800 GHz.

• ETRI Journal
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• v.31 no.3
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• pp.315-317
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• 2009

In this letter, a novel antenna with a miniaturized aperture is proposed. The substrate including a split-ring resonator array is inserted into a size-reduced open-ended waveguide. For a low return loss and high radiation efficiency, the ring arrangement is optimized, and a stepped transition using H-plane discontinuity is proposed. The proposed antenna achieves a 70% aperture reduction compared to a conventional standard waveguide antenna of WR-187 (47.6 mm${\times}$22.2 mm). The return loss drops significantly at three frequencies, and a reasonable gain is achieved. The aperture-miniaturized antenna can be used in many antenna applications such as near-field measurement.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.2
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• pp.202-207
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• 2010

In this paper, a novel voltage-controlled oscillator(VCO) using the open loop multiple split ring resonator(OLMSRR) is presented for improving the phase noise, implemented in 130 nm CMOS technology. Compared with the conventional CMOS LC resonator, the proposed CMOS OLMSRR has the larger coupling coefficient value, which makes a higher Q-factor, and has improved the phase noise of the VCO. The proposed CMOS VCO based OLMSRR has the phase noise of -99.67 dBc/Hz @ 1 MHz in the oscillation frequency. Compared with the VCO using the conventional CMOS LC resonator and the proposed VCO using the CMOS OLMSRR structure has been improved in 7 dB. The prototype 24 GHz CMOS VCO is implemented in 130 nm CMOS and occupies a compact die area of $0.7\;mm{\times}0.9\;mm$.