W-band Downconversion Mixer with Finline Transition for Intelligent Traffic System

Seonghan Ryu(류성한) 한국정보기술학회 2016 한국정보기술학회논문지 Vol.14 No.10

A W-band MMIC mixer using 0.15-㎛ T-gate GaAs pHEMT technology is presented. The proposed mixer is designed as a single balanced diode mixer type with schottky barrier diode and implemented with finline transition for 77-㎓ intelligent traffic system(ITS) transceiver(TRx) module. The mixer also includes an IF amplifier to increase a conversion gain, and the waveguide-to-microstrip antipodal finline transition is designed with cosine-squared taper function curve and fabricated with duroid 5880 substrate. The optimized finline transition shows the measured insertion loss of less than 1㏈ and the return loss of higher than 20㏈ for 77㎓. The measured conversion gain of the proposed W-band mixer is 0.3㏈ at LO power of 11㏈m, which satisfies the mixer specification for ITS automotive collision avoidance radar receiver module.

Design of a Low Noise Bias Generator for Multi-band RF CMOS Transceiver

Seonghan Ryu 한국정보기술학회 2013 한국정보기술학회논문지 Vol.11 No.2

A low noise bias generator for RF CMOS transceiver is proposed and implemented. The bias generator consists of a bandgap reference(BGR) and a low dropout regulator(LDO). In RF transceiver, the bias blocks determining bias quantity and quality of the signal-processing circuits are separately placed near each signal block for noise performance and proper power dividing. Therefore, bias block design issues such as power consumption, noise and chip size should be considerd for multi-band RF CMOS transceiver which has various circuit blocks and chip area constraints. This paper describes a design procedure and techniques for a low noise bias generator. The proposed techniques allow good trade-off among chip size, noise and power consumption. The bias generator gives temperature compensated bandgap reference of 1.2V with mean temperature dependency of 5ppm/˚C for -25˚C to 75˚C. The LDO is able to drive max bias current of 15mA. The bias generator is implemented in a 0.18m RF CMOS technology with a size of 0.2×0.4mm2 and consumes a bandgap core current of 40A at 2.5V supply and works for a power supply down to 1.8V. Output noise level is below 30nV/√Hz at 100kHz. A CMOS VCO with the proposed bias generator has the phase noise difference of only 2.2dBc/Hz at 400kHz offset.

Wide Tuning-range LO Chain with a Hybrid Inductor for LTE and SAW-less GSM Transceiver

Seonghan Ryu 대한전자공학회 2021 IEIE Transactions on Smart Processing & Computing Vol.10 No.6

A low phase noise, multi-standard local oscillator (LO) chain for LTE and GSM is presented. The LO chain is composed of a dynamic divider and a CMOS VCO with a hybrid inductor using both bondwire and a planar spiral inductor in the same area. This approach improves both tuning range and phase noise characteristics without additional area loss. Based on this concept, the LO chain with a hybrid inductor VCO is implemented in a 65nm CMOS process. The measured performance satisfies wide tunability and most stringent GSM transmitter phase noise specification, which proves that the LO chain can be used for LTE and SAW-less GSM transceiver.

Low Phase Noise CMOS VCO with Hybrid Inductor

Ryu, Seonghan The Institute of Electronics and Information Engin 2015 IEIE Transactions on Smart Processing & Computing Vol.4 No.3

A low phase noise CMOS voltage controlled oscillator(VCO) for multi-band/multi-standard RF Transceivers is presented. For both wide tunability and low phase noise characteristics, Hybrid inductor which uses both bondwire inductor and planar spiral inductor in the same area, is proposed. This approach reduces inductance variation and presents high quality factor without custom-designed single-turn inductor occupying large area, which improves phase noise and tuning range characteristics without additional area loss. An LC VCO is designed in a 0.13um CMOS technology to demonstrate the hybrid inductor concept. The measured phase noise is -121dBc/Hz at 400KHz offset and -142dBc/Hz at 3MHz offset from a 900MHz carrier frequency after divider. The tuning range of about 28%(3.15 to 4.18GHz) is measured. The VCO consumes 7.5mA from 1.3V supply and meets the requirements for GSM/EDGE and WCDMA standard.

Design Issues of CMOS VCO for RF Transceivers

Seonghan Ryu 한국전자파학회JEES 2009 Journal of Electromagnetic Engineering and Science Vol.9 No.1

This paper describes CMOS VCO circuit design procedures and techniques for multi-band/multi-standard RF transceivers. The proposed techniques enable a 4 ㎓ CMOS VCO to satisfy all requirements for Quad-band GSM/EDGE and WCDMA standards by achieving a good trade-off among important specifications, phase noise, power consumption, modulation performance, and chip area efficiency. To meet the very stringent GSM T/Rx phase noise and wide frequency range specifications, the VCO utilizes bond-wire inductors with high-quality factor, an 8-bit coarse tune capbank for low VCO gain(30~50 ㎒/V) and an on-chip 2nd harmonic noise filter. The proposed VCO is implemented in 0.13 ㎛ CMOS technology. The measured tuning range is about 34 %(3.17 to 4.49 ㎓). The VCO exhibits a phase noise of -123 ㏈c/㎐ at 400 ㎑ offset and -145 dBc/㎐ at 3 ㎒ offset from a 900 ㎒ carrier after LO chain. The calculated figure of merit(FOM) is -183.5 ㏈c/㎐ at 3 ㎒ offset. This fully integrated VCO occupies 0.45×0.9 ㎟.

Noise Optimized Channel Selection Filter Design for WCDMA

Seonghan Ryu 보안공학연구지원센터 2016 International Journal of Software Engineering and Vol.10 No.8

A low noise 6th-order elliptic low-pass filter is proposed and implemented. For the high level integration of multi-standard wireless terminal at low cost, the direct conversion architecture is favored for the RF transceiver, and a low noise channel selection filter with enough out-of-band suppression takes a critical role for the direct conversion receiver. For the noise optimized filter design, a noise analysis, design procedure and techniques are described for a biquad circuit and the 6th- order elliptic filter. The filter is implemented in a 0.35μm BiCMOS technology and has the 3dB cutoff frequency of 2.3MHz. The chip size is 1.0×1.15mm2. The measurement results show that the noise characteristics are optimized by proper allocation of the biquad circuit component values and biquad placement as proposed. And also, the filter shows good linearity. The filter consumes 3.8mA current at 1.8V supply and provides about 60dB stopband rejection, input referred noise of 27 .8 nV Hz and IIP3 of 22.4 dBm. The filter performance meets the WCDMA standard specification.

광대역 저잡음 CMOS VCO를 위한 Inductor 설계 Issue

류성한(Seonghan Ryu) 한국정보기술학회 2015 한국정보기술학회논문지 Vol.13 No.9

An inductor structure for low phase noise CMOS VCO with wide tuning range is proposed in this paper. The proposed inductor is designed to have both low inductance for wide tuning range and high quality factor for low phase noise, and is implemented as a planar spiral inductor and a 3-D bondwire inductor structure considering a frequency bandwidth, a phase noise specification and a chip size. To prove the performance of the proposed inductor structure, two CMOS VCOs are designed, fabricated and measured. RFID VCO shows the tuning range of 415MHz for 1.7GHz carrier, the phase noise of -120.7dBc/Hz at 200KHz offset and the power consumption of 21mA for 1.8V. WCDMA shows the tuning range of 1GHz for 3.7GHz carrier, the phase noise of -130.1dBc/Hz at 3MHz offset and the power consumption of 7.5mA for 1.3V. Two VCOs satisfy each standard specification and a FOM is -184.1 for RFID VCO, -181.7 for WCDMA VCO, which shows good performance of the proposed inductor VCOs.

Intestinal Enterococcus population affects Galleria mellonella metamorphosis

Seonghan Jang,Hyun Gi Kong,Jin-Soo Son,Joon-Hui Chung,Soohyun Lee,Jun-Seob Kim,Choong-Min Ryu 한국응용곤충학회 2023 한국응용곤충학회 학술대회논문집 Vol.2023 No.10

Microbes in insect gut significantly influence host physiology. While Lepidoptera is a diverse insect order, the relationship between microbial symbiosis and host development remains elusive, especially concerning role of gut-colonizing bacteria in metamorphosis. We investigated the gut microbial diversity in Galleria mellonella throughout its life cycle using 16S rRNA amplicon sequencing. Our findings revealed a predominance of Enterococcus spp. in larvae and Enterobacter spp. in pupae. Remarkably, removing Enterococcus spp. hastened the larval-to-pupal transition. Transcriptome analysis showed an upregulation of immune response genes in pupae and hormone genes in larvae. Notably, the production of antimicrobial peptides in the host gut varied with developmental stages. Some of these peptides suppressed the growth of Enterococcus innesii, a dominant gut bacterium in G. mellonella larvae. This research underscores the pivotal role of gut microbiota shifts in metamorphosis, driven by the secretion of antimicrobial peptides in the G. mellonella digestive system.

디스플레이 화면에 추가적인 정보 출력을 위한 도트 패턴 인식 연구

신성한(Seonghan Shin),박재영(Jaeyoung Park),김태훈(Taehoon Kim),홍학표(Hakpyo Hong),이상준(Sangjoon Lee),유영기(Young-Kee Ryu) 대한전기학회 2018 대한전기학회 학술대회 논문집 Vol.2018 No.-

X-band CMOS VCO for 5 GHz Wireless LAN

kim, Insik,Ryu, Seonghan The Institute of Internet 2020 International journal of advanced smart convergenc Vol.9 No.1

The implementation of a low phase noise voltage controlled oscillator (VCO) is important for the signal integrity of wireless communication terminal. A low phase noise wideband VCO for a wireless local area network (WLAN) application is presented in this paper. A 6-bit coarse tune capacitor bank (capbank) and a fine tune varactor are used in the VCO to cover the target band. The simulated oscillation frequency tuning range is from 8.6 to 11.6 GHz. The proposed VCO is desgned using 65 nm CMOS technology with a high quality (Q) factor bondwire inductor. The VCO is biased with 1.8 V VDD and shows 9.7 mA current consumption. The VCO exhibits a phase noise of -122.77 and -111.14 dBc/Hz at 1 MHz offset from 8.6 and 11.6 GHz carrier frequency, respectively. The calculated figure of merit(FOM) is -189 dBC/Hz at 1 MHz offset from 8.6 GHz carrier. The simulated results show that the proposed VCO performance satisfies the required specification of WLAN standard.