• JSTS:Journal of Semiconductor Technology and Science
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• v.1 no.3
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• pp.193-196
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• 2001

For wide locking range, an analog delay locked loop (DLL) was designed with the selective phase inversion scheme and the variable number of delay elements. The number of delay elements was determined adaptively depending on the clock cycle time. During the analog fine locking stage, a self-initializing 3-state phase detector was used to avoid the initial state problem associated with the conventional 3-state phase detector. With these schemes, the locking range of analog DLL was increased by four times compared to the conventional scheme according to the simulation results.

• JSTS:Journal of Semiconductor Technology and Science
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• v.17 no.4
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• pp.492-498
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• 2017

In this paper, we integrate a divide-by-3 injection-locked frequency divider (ILFD) in CMOS technology with a $0.18-{\mu}m$ BiCMOS process. We propose a self-injection technique that utilizes harmonic conversion to improve the locking range, phase-noise, and input sensitivity simultaneously. The proposed self-injection technique consists of an odd-to-even harmonic converter and a feedback amplifier. This technique offers the advantage of increasing the injection efficiency at even harmonics and thus realizes the low-power implementation of an odd-order division ILFD. The measurement results using the proposed self-injection technique show that the locking range is increased by 47.8% and the phase noise is reduced by 14.7 dBc/Hz at 1-MHz offset frequency with the injection power of -12 dBm. The designed divide-by-3 ILFD occupies $0.048mm^2$ with a power consumption of 18.2-mW from a 1.8-V power supply.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.34D no.6
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• pp.58-64
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• 1997

The wavelengt lockin gsystem of the optical fabry-perot filter theoretially derived and experimentally realized by using the ithering method in order to compensate the laser wavelength drift increasing the BER of the WDM system. The deviation between the laser wavelength and the optical filter center wavelength is compensated by applying a suitable voltage to the PZT. Accordingly, the laser wavelength selected by the fabry-perot filter always maintains the condition of maximum transmission powr. A wavelength locking system has been demonstrated using a fiber fabry-perot filter with a free spectral range of 80nm and an FWH of 1nm. The voltages of the sine wave generated for dithering was 20mV and 10mV, the frequency was 2kHz and center wavelength of the tunable laser was 1550nm. In this paper, the locking system have 20ms of locking time and 2nm of locking range.

• Proceedings of the IEEK Conference
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• 1999.11a
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• pp.340-343
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• 1999

In this paper, we propose a wide range PLL(Phase Locked Loop) for 64X CD-ROMs & l0X DVD-ROMs. The frequency locking range of the Proposed PLL is 75MHz~370MHz. To reduce jitters caused by large VCO gain and supply voltage noise, a new V-I converter and a differential delay cell are used in 3-stage ring VCO, respectively. The new V-I converter has a 0.6V ~ 2.5V wide input range. In addition, we propose a new charge pump which has perfect current matching characteristics for the sourcing/sinking current. This new charge pump improves the locking time and the locking range of the PLL. This Chip is implemented in 0.25${\mu}{\textrm}{m}$ CMOS process. It consumes 55㎽ in worst case with a single 2.5V power supply.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.9
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• pp.2362-2372
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• 1996

This paper deals with the design and development of an Injection-Locking Coupled Oscillators(ILCO), which functions like phase-shifter in the Active Intergrated Phased Array Antenna(AIPAA). This linear array 2-element ILCO consists of two Injection Locking Hair-pin Resonator Oscillators(ILHRO) and an unilateral amplifier. The first and second elements of the ILCO have same frequency tuning range but locking bandwidths of 11.5MHz and 14MHz respectively. A phase shift of .DELTA..PHI.=158.4.deg.(-78.0.deg. to 80.4.deg.) could be obtained inthe second element of ILCO when the first elementof the ILCO was in the reference locking mode(.DELTA..PHI.=0.deg.). When the ILCO is applied to the AIPAA, the predicted beam scanning angle value will be 38.4.deg.. Each ILCO gives good frequency stability and lower AM, FM, and PM noise charactheristics in the mutual coupling lockingmode. The ILCO can not only play a part as the phase shifter for the AIPAA but it can also be usedas the power combining device in the mm-wave frequency range and as a part of a T/R MMIC module.

• Proceedings of the IEEK Conference
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• 2003.07b
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• pp.963-966
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• 2003

This paper proposes a new locking algorithm of the delay locked loop (DLL) which reduces the lock-acquisition time and eliminates false locking problem to enlarge the operating frequency range. The proposed DLL uses the modified phase frequency detector (MPFD) and the modified charge pump (MCP) to avoid the false locking problem. Adopting a new lock detector that measures delay between elects helps the fast lock-acquisition time greatly. The idea has been confirmed by HSPICE simulations in a 0.35-${\mu}{\textrm}{m}$ CMOS process.

• 전자공학회논문지 IE
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• v.46 no.1
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• pp.1-6
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• 2009

This paper presents the digital PLL architecture and design for improving the frequency detection range and locking time for wide-band frequency synthesizer applications. In this research, a wide-range digital logic quadricorrelator is used for wide-band and fast frequency detector and sigma-delta modulator with 2-bit up-down counter is adopted for DCO control. The proposed digital PLL reduces the phase noise from quantization effect and is suitable for implementation of wide-band fast-locking as well as low power features, which is in high demand for mobile multimedia applications.

• Proceedings of the Korea Concrete Institute Conference
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• 1998.10c
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• pp.157-160
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• 1998

KS F 4419, which is dealt with the Inter-Locking block, states that water to cement ratio for manufacturing inter-locking block should be less than 25% and in KS F4419, the use of admixture is shown to be reluctant to recommend. In this paper, reinvestigation of some regulations in KS F 4419 are carried out. According to the experimental results, as W/C increases, flexural strength and compressive strength are tended to decrease, whereas they increases within certain range, Flexural strength and compressive strength have higher values in 1:2(W/C=35%), 1:4(W/C=45%) and 1:6(W/C=55%) of mix proportions. Moreover they have rather higher values with the containment of high range AE water-reducing agent. The absorption ratios decrease with the increase of W/C and the containment of high range AE water-reducing agent. Therefore, the regulations on the W/C and admixture in KS F 4419 reguire revision.

• Current Optics and Photonics
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• v.5 no.4
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• pp.384-390
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• 2021

This paper presents a wide-range tunable wavelength-locking technology based on optoelectronic oscillation (OEO) loops for optical fiber sensors and microwave photonics applications, explains the theoretical fundamentals of the design, and demonstrates a method for locking the relative wavelength differences between a leader semiconductor laser and its follower lasers. The input of the OEO loop in the proposed scheme (the relative wavelength difference) determines the radio-frequency (RF) signal frequency of the oscillation output, which is quantized into an injection current signal for feedback to control the wavelength drift of follower lasers so that they follow the wavelength change of the leader laser. The results from a 10-hour continuous experiment in a field environment show that the wavelength-locking accuracy reached ±0.38 GHz with an Allan deviation of 6.1 pm over 2 hours, and the wavelength jitter between the leader and follower lasers was suppressed within 0.01 nm, even though the test equipment was not isolated from vibrations and the temperature was not controlled. Moreover, the tunable range of wavelength locking was maintained from 10 to 17 nm for nonideal electrical devices with limited bandwidth.

• Clinics in Shoulder and Elbow
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• v.20 no.4
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• pp.217-221
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• 2017

Background: The purpose of this study was to evaluate the clinical and radiographic outcomes of internal fixation with locking T-plates for osteoporotic fractures of the proximal humerus in patients aged 65 years and older. Methods: From January 2007 through to December 2015, we recruited 47 patients aged 65 years and older with osteoporotic fractures of the proximal humerus. All fractures had been treated using open reduction and internal fixation with a locking T-plate. We classified the fractures in accordance to the Neer classification system; At the final follow-up, the indicators of clinical outcome-the range of motion of the shoulder (flexion, internal rotation, and external rotation) and the presence of postoperative complications-and the indicators of radiographic outcome-the time-to-union and the neck-shaft angle of the proximal humerus-were evaluated. The Paavolainen method was used to grade the level of radiological outcome in the patients. Results: The mean flexion was $155.0^{\circ}$ (range, $90^{\circ}-180^{\circ}$), the mean internal rotation was T8 (range, T6-L2), and the mean external rotation was $66.8^{\circ}$ (range, $30^{\circ}-80^{\circ}$). Postoperative complications, such as plate impingement, screw loosening, and varus malunion were observed in five patient. We found that all patients achieved bone union, and the mean time-to-union was 13.5 weeks of the treatment. The mean neck-shaft angle was $131.4^{\circ}$ at the 6-month follow-up. According to the Paavolainen method, "good" and "fair" radiographic results each accounted for 38 and 9 of the total patients, respectively. Conclusions: We concluded that locking T-plate fixation leads to satisfactory clinical and radiological outcomes in elderly patients with proximal humeral fractures by providing a larger surface area of contact with the fracture and a more rigid fixation.