So Young Kang

Publications (2)1.72 Total impact

• Article: A 2.16 mW Low Power Digitally-Controlled Variable Gain Amplifier

  So Young Kang, Jooyoung Jang, Inn-Yeal Oh, Chul Soon Park
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  ABSTRACT: A low power digitally-controlled CMOS variable gain amplifier (VGA) was fabricated in a TSMC 0.18 ??m CMOS technology. By extending the transconductor operation range from saturation mode for high gain to triode mode for low gain, the proposed VGA can obtain a wide gain range with low power dissipation. The power consumption of the proposed VGA is as small as 2.16 mW while keeping a wide gain range of 53 dB. The proposed VGA has a controlled gain from -22 dB to 31 dB with 1 dB steps. When the proposed VGA was set to a maximum gain, the total harmonic distortion (THD) and the 3 dB bandwidth are -48 dB and at least 65 MHz, respectively.
  IEEE Microwave and Wireless Components Letters 04/2010; · 1.72 Impact Factor
• Conference Proceeding: A 0.75–6.75 GHz receiver with a digitally controlled LO generator for software-defined radio

  Hyun Seok Choi, Quang Diep Bui, So Young Kang, Joo Young Jang, Un Bong Lee, Chan Ho Chun, Inn Yeal Oh, Chul Soon Park
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  ABSTRACT: This paper describes a receiver composed of a wideband LNA, mixers, and a frequency generator toward multifunction and multistandard mobile terminals. The proposed frequency generator can cover the frequency range from 750 MHz to 6.75 GHz by following the frequency planning which consists of a VCO, two mixers, and four divide-by-2 dividers. Firstly, to achieve better phase noise, a low-phase noise wideband LC VCO is proposed. The power consumption of the VCO is 7.8 mW and its phase noise is -126 dBc/Hz at 1 MHz offset frequency. The LO generator is controlled for the targeted frequency range by turning on and off the mixer and divider input and output buffers. The total power consumption of the LO generator is 27.3~60.6 mW under 1.8 V supply. The phase noise at 1 MHz offset for each frequency band varies from -122 dBc/Hz to -136 dBc/Hz. A 2-stage wideband low noise amplifier has bandwidth of 6.6 GHz (0.2-6.8 GHz), power gain of 13.3 dB including 6 dB loss from buffers, and minimum noise figure of 3.7 dB.
  RF Front-ends for Software Defined and Cognitive Radio Solutions (IMWS), 2010 IEEE International Microwave Workshop Series on; 03/2010