• Journal of Korea Society of Industrial Information Systems
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• v.20 no.1
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• pp.49-55
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• 2015

This paper proposes a 2.4 GHz RF oscillator with a very low close-in phase noise performance. This is composed of a low frequency crystal oscillator and three frequency multipliers such as two doubler (X2) and one tripler (X3). The proposed oscillator is implemented as a hybrid type circuit design using a discrete silicon bipolar transistor. The measurement results of the proposed oscillator structure show -115 dBc/Hz close-in phase noise at 10 kHz offset frequency, while only dissipating 5 mW from a 1-V supply. Its close-in phase noise level is very close to that of a low frequency crystal oscillator with little degradation of noise performance. The proposed structure which is consisted of a low frequency crystal oscillator and a frequency multiplier provides new method to implement a low power low close-in phase noise RF local oscillator.

• Journal of the Korea Institute of Military Science and Technology
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• v.16 no.3
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• pp.373-381
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• 2013

In this paper, the effects of phase noise on the radar system were analyzed in terms of 3 point of view. The impact(s) on the compressed pulse waveform, the FMICW(Frequency Modulated Interrupted Continuous Wave) radar performance and the receiver sensitivity were investigated. From the investigation, it was indicated that the phase noise over 10 kHz offset frequency makes the side lobe level of compressed pulse worse. Also it was founded that the FMICW radar performance, especially at the noise level of range profile, is related to the phase noise. Finally, the investigation showed that the phase noise at local oscillator affects the receiver sensitivity.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.7
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• pp.1247-1253
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• 2007

The system phase noise spectrum distribution for COMS sensor data transmitter and receiver system was proposed in this paper. On the basis of the analyzed design parameter to reduce the phase noise effect in a receiver, the optimal system phase noise were proposed for raw, IRIT and HRIT data transmission that are sensor data, respectively. The proposed system phase noise provides the qualified transmission performance of sensor data and reduces the performance degradation due to phase noise generating in the transmission channel. Also the system phase noise spectrums are utilized in the design of frequency generation source for sensor data transmission and receiver system.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2003.11a
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• pp.155-159
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• 2003

This paper presents fully integrated 5 GHz band low phase noise LC tank VCO. The implemented VCO is tuned by integrated PN diode and tuning rage is $5.01{\sim}5.30$ GHz under $0{\sim}3 V$ control voltage. For good phase noise performance, LC filtering technique, common in Si CMOS process, is used, and to prevent degradation of phase noise performance by collector shot-noise and to reduce power dissipation the HBT is biased at low collector current density bias point. The measured phase noise is -87.8 dBc/Hz at 100 kHz offset frequency and -111.4 dBc/Hz at 1 MHz offset frequency which is good performance. Moreover phase noise is improved by roughly 5 dEc by LC filter. It is the first experimental result in InGaP/GaAs HBT process. The figure of merit of the fabricated VCO with LC filter is -172.1 dBc/Hz. It is the best result among 5 GHz InGaP HBT VCOs. Moreover this work shows lower DC power consumption, higher output power and more fixed output power compared with previous 4, 5 GHz band InGaP HBT VCOs.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.2
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• pp.152-160
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• 2008

In this paper, we analyze the performance of a direct-conversion UHF RFID reader with the range correlation effects of the phase noise. Since a UHF RFIB system uses the same oscillator to generate the transmitted carrier and the local oscillation, the periodic interference and phase noise reduction effects occur due to time delay between two signals. Through exact theory and simulation, we verify how to cancel the periodic interference phenomena using I/Q diversity combining technique. And, we analyze phase noise reduction effects due to range correlation as a function of the tag-reader distance and the offset frequency Using these results, we simulate the symbol-error-rate performance with respect to phase noise with and without range correation effects. We show that the phase noise of the local oscillator has little effect on the symbol-error-rate performance because of phase noise reduction by range correlation.

• Proceedings of the IEEK Conference
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• 1999.06a
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• pp.695-698
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• 1999

Passive noise reduction is a classical approach to attenuate industrial noise. But Active noise cancellation has several advantages over the passive noise cancellation. Such a system offers a better low frequency performance with a smaller and lighter system. This paper presents an active closed loop control system which consists of an controller for inverting and compensating the phase delay, an microphone for picking up the external noise, and loudspeaker for radiating the acoustic anti-phase signal to reduce external noise. The noise in the phase delay covered from 80$^{\circ}$ to 270$^{\circ}$ tends to be reduced. The degree of noise cancellation obtainable with this system reaches value about 17㏈.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.4
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• pp.481-488
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• 2011

In this paper, we study a novel wireless interference cancellation system(ICS) repeater based on OFDM system with phase noise analysis and performance evaluation. Recently, there were many researches about wireless repeater. The previous study is just considering the feedback channel cancellation algorithm. But, in wireless repeater system, the phase noise effect can exist at up and down converter of wireless repeater. In wireless repeater system, if there are phase noise effects, the performance of system will get worse. So, the phase noise compensator is needed in wireless repeater. Therefore, we propose adaptive phase noise compensator based on OFDM system in order to effectively cancel phase noise. In order to cancel interference, we adapt adaptive phase noise compensator in wireless repeater system. The adaptive phase noise compensator compensates phase noise effect. Therefore, in this paper, we analyze phase noise of wireless repeater based on OFDM system. In this paper, when phase noise power is -15 dBc and phase noise cutoff frequency is 100 kHz at 4QAM, the BER performance of propose algorithm is better about 4 dB than with adaptive equalizer and without phase noise compensator at $10^{-4}$.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.48 no.12
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• pp.28-34
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• 2011

In this paper, a PLL frequency synthesizer for RSSI applications is designed by phase noise analysis. Required synthesizer performance is achieved by optimizing the noise performance of PLL components and a loop transfer function, since its phase noise, lock time, and spur suppression capability are determined by the performance of loop components and loop filter characteristics. As an application example, a PLL frequency synthesizer for RSSI applications, which operates at the frequency of 2.288GHz, is designed using the phase noise analysis. The validity of the design technique is proved by experiments.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.2A
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• pp.155-163
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• 2009

OFDM System is a promising transmission technique due to its spectral efficiency But, a major disadvantage of the OFDM system is its sensitivity to frequency offset and phase noise that makes intercarrier interference (ICI), which degrades the system performance severely The ICI self-cancellation method has a good performance with frequency offset or phase noise. This paper proposed the N/2 spacing data-conjugate method that works well in large frequency offset and phase noise (normalized frequency offset=0.2-0.4, phase noise standard deviation=about lodes). Also, an efficiency ICI cancellation method using pilot was proposed. Simulation results confirm that performance of the proposed scheme is better than conventional schemes.

• ETRI Journal
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• v.33 no.2
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• pp.176-183
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• 2011

This paper presents a new analytical approach and experimental verification for the improvement of noise performance in phased-array receivers. For analysis purposes, a multi-channel array system is converted into an equivalent single-channel system, such that the two presents the identical signal and noise powers at the output, respectively. We define an effective gain, noise figure, and signal-to-noise ratio in the equivalent system. Through the proposed approach, the noise performance of the array receiver is analyzed in a general and straightforward manner and then compared to that of each individual array channel. In addition, the phase noise of the array system is analyzed in a rigorous manner, showing its effective reduction by a factor of the array size. The predicted improvement of the noise performance is experimentally confirmed with a CMOS integrated phased-array receiver.