인덕터 피킹 기법을 이용한 인버터 구조의 광대역 CMOS 저잡음 증폭기 설계

정지학(Ji-Hak Jung) 산업기술교육훈련학회 2019 산업기술연구논문지 (JITR) Vol.24 No.1

본 논문에서는 3.1∼10.6 GHz의 주파수에서 동작하는 CMOS 초광대역 저잡음 증폭기 구조를 제안한다. 제안된 광대역 저잡음 증폭기는 2단의 구조로 설계 되었으며, 저잡음 증폭기의 1단 구조는 광대역 특성을 얻기 하여 저항 피드백과 인덕터 피킹 기법을 활용한 Inverter 기반의 구조를 적용하였으며, 2단 구조는 높은 전력이득과 광대역 특성을 확보하기 위하여 RC 피드백 common-source 구조를 적용하였다. 본 논문에서 제안된 광대역 저잡음 증폭기는 TSMC 0.18-  CMOS 파운드리 Post-layout 시뮬레이션을 수행하였으며, 시뮬레이션 특성 결과는 3.1∼10.6 GHz 대역 내에서 전력 이득은 14.3∼16.9 dB, 입력·출력 정합은 –10 dB 이하, 잡음지수는 3.4∼4 dB, 입력   는 -1 dBm 이고, 전체 소비전력은 27 mW를 가진다.

RF Front-End 에 적용 가능한 광대역 저잡음 증폭기 설계

정지학(Ji-Hak Jung) 대한전기학회 2022 대한전기학회 학술대회 논문집 Vol.2022 No.10

주파수 대역 저지 특성을 갖는 초광대역 안테나

최우영,정지학,정경호,최재훈,Choi Woo-Young,Jung Ji-Hak,Chung Kyung-Ho,Choi Jae-Hoon 한국전자파학회 2005 한국전자파학회논문지 Vol.16 No.2

In this paper, a novel compact and frequency band-notch antenna for Ultra-Wideband(UWB) applications is proposed. The designed antenna not only shows good impedance bandwidth for ultra-wideband but has band notch characteristic for the frequency band of $5.15\~5.825\;GHz$ limited by IEEE 802.1la and HIPERLAN/2. To achieve both properties of wide band and band notch, the techniques of a concaved ground plane and inserted U-shaped thin slot into planar radiator are used respectively. A manufactured antenna satisfied VSWR<2 for the frequency band of $2.95\~11.7\GHz$ except the limited band of $4.92\~5.866\;GHz$. 본 논문에서는 Ultra-Wideband(UWB)통신을 위한 새로운 소형 주파수 대역 저지 안테나를 설계 및 제작한다. 설계된 안테나는 초광대역 특성을 만족하면서, IEEE 802.11a와 HIPERLAN/2에 의해 사용이 제한된 $5.15\~5.825\;GHz$에서 주파수 대역 저지 특성을 갖는다. 안테나의 광대역 특성을 얻기 위해서 요철 모양의 접지면을 구현하였고, 또한 제한된 주파수 대역에서 저지 특성을 갖기 위해 U모양의 얇은 슬랏을 사각형 복사 패치 위에 구현 하였다. 제작된 안테나는 저지 대역인 $4.92\~5.866\;GHz$을 제외하고 $2.95\~11.7\;GHz$ 대역에서 정재파비 2 이하를 만족하는 광대역 특성을 나타낸다.

Filed Programmable Logic Control and Test Pattern Generation for IoT Multiple Object switch Control

김응주,정지학,Kim, Eung-Ju,Jung, Ji-Hak The Korea Internet of Things Society 2020 한국사물인터넷학회 논문지 Vol.6 No.1

사물인터넷 환경에서 다중 객체의 스위치 제어는 고전압을 구동하기 위해 레벨 시프터가 있는 여러 솔리드 스테이트 구조로써 낮은 ON 저항과 양방향 릴레이 MOS 스위치를 통합했으며 외부 직렬 논리 제어에 의해 독립적으로 제어되어야 한다. 이 장치는 의료용 초음파 이미지 시스템, 잉크젯 프린터 제어 등의 IoT 기기뿐만 아니라, 켈빈 4 단자 측정을 사용한 PCB 개방 / 단락 및 누출 테스트 시스템과 같은 저전압 제어 신호에 의한 고전압 스위칭 제어가 필요한 응용 제품에 사용하도록 설계되었다. 이 논문에서는 FPGA (Field Programmable Gate Array) 테스트 패턴 생성을 사용한 아날로그 스위치 제어 블록의 구현 및 검증에 대하여 고찰하였다. 각 블록은 Verilog 하드웨어 설명 언어를 사용하여 구현된 후 Modelsim에 의해 시뮬레이션 되고 FPGA 보드에서 프로토타입화 되어 적용되었다. 제안된 아키텍처는 IoT 환경에서 여러개의 개체들을 동시에 제어하여야 하는 분야에 적용할 수 있으며 유사 형태의 IC를 테스트하기 위해 제안된 패턴 생성 방법을 적용할 수 있다. Multi-Channel Switch ICs for IoT have integrated several solid state structure low ON-resistance bi-directional relay MOS switches with level shifter to drive high voltage and they should be independently controlled by external serialized logic control. These devices are designed for using in applications requiring high-voltage switching control by low-voltage control signals, such as medical ultra-sound imaging, ink-jet printer control, bare board open/short and leakage test system using Kelvin 4-terminal measurement method. This paper describes implementation of analog switch control block and its verification using Field programmable Gate Array (FPGA) test pattern generation. Each block has been implemented using Verilog hardware description language then simulated by Modelsim and prototyped in a FPGA board. Compare to conventional IC, The proposed architecture can be applied to fields where multiple entities need to be controlled simultaneously in the IoT environment and the proposed pattern generation method can be applied to test similar types of ICs.

시험관 아기 시술에서 여성의 연령이 수정란의 질과 다태 임신 발생에 미치는 영향

이명섭,박장옥,정지학,박준숙,강희규,김동훈,이호준,Lee, Myeong-Seop,Park, Jang-Ok,Jung, Ji-Hak,Park, Jun-Suk,Kang, Hee-Gyoo,Kim, Dong-Hoon,Lee, Ho-Joon 대한생식의학회 2000 Clinical and Experimental Reproductive Medicine Vol.27 No.3

Objective: This study was performed to evaluate the influence of maternal age on embryo quality and the frequency of multiple pregnancy in IVF-ET program. Method: 86 conventional IVF-ET cycles were divided into three groups according to the age by 5 year (group A: 26-30, group B: 31-35, group C: 36-40 yrs). The in vitro fertilization and development outcome (fertilization, cleavage and high quality embryo rate) and the pregnancy outcome (pregnancy, implantation, G-sac/high quality embryo and multiple pregnancy rate) were examined. And then, these results were compared among the groups. Results: The rates of fertilization (62.7, 68.5 and 65.4%, respectively) and cleavage (95.6, 97.6 and 98.0%, respectively) were not different among the groups. And the high quality embryo (HQE) rate also was not different among the groups (61.8, 62.9 and 62.8%, respectively). The pregnancy rate of group C (23.3%) was significantly lower than that of group A (41.2%) and B (48.7%). And the implantation rate was significantly decreased with advance in maternal age (group A; 17.3%, B; 12.6% and C; 6.0%). The G-sac/high quality embryo rate was significantly higher in group A (70.8%) when compared to group B (32.2%) and C (40.0%). On the other hand, the multiple pregnancy rate was significantly lower in group C (14.3%) when compared to group A (71.4%) and B (36.8%). Conclusion: The pregnancy rate was significantly decreased over 35 years. The G-sac/HQE and multiple pregnancy rate were significantly high below 31 years. Thus, these results suggest that the number of high quality embryo transferred should be limited by the age and another criteria for embryo quality evaluation were required for single embryo transfer.

UWB용 대역 저지 필터 설계

노양운,홍석진,정경호,정지학,최재훈,Roh Yang-Woon,Hong Seok-Jin,Chung Kyung-Ho,Jung Ji-Hak,Choi Jae-Hoon 한국전자파학회 2006 한국전자파학회논문지 Vol.17 No.2

본 논문에서는 초광대역(UWB: Ultra-Wideband) 무선 통신 시스템에 적합한 소형의 마이크로스트립 대역 저지 필터를 제안한다. 제안된 필터는 $50{\Omega}$ 마이크로스트립 선로 좌측에 단락 스터브(short-circuited)를 이용한 고역 필터와 우측에 결합 공진기를 이용한 대역 저지 필터를 합성하였다. 3.1 GHz에서 10.6 GHz까지의 초광대역 특성을 갖는 고역 필터를 설계하기 위해서 the mixed lumped/distributed(L/D) 방법을 이용하였다. 또한 원하는 주파수 대역의 협대역 저지 필터를 설계하기 위해서 3개의 결합 공진기(coupled resonator)를 이용하였다. 공진기를 미앤더(meander) 형태로 구현함으로써 L-형태의 공진기에 비해 면적을 $29\%$ 정도 소형화시켰다. 측정 결과 3-dB 삽입 손실을 기준으로 $146.7\;\%(2.1\;GHz{\sim}10.15\;GHz)$의 광대역 통과 특성을 얻었으며 $10.04\;\%(5.2\;GHz{\sim}5.75\;GHz)$의 저지 대역을 나타내었다. 측정된 군 지연(group delay) 특성은 저지 대역을 제외한 주파수 대역에서 0.7 ns 미만이다. A compact microstrip band-selective filter for ultra-wideband(UWB) radio system is proposed. The filter combines the traditional short-circuited stub highpass filter and coupled resonator band-stop filter on both sides of the mitered 50-ohm microstrip line. To realize the pseudo-highpass filtering characteristic over UWB frequency band(3.1 GHz to 10.6 GHz), a distributed highpass filter scheme is adopted. Three coupled resonators are utilized to obtain the band stop function at the desired frequency band. By meandering the coupled resonators, there is $29\;\%$ size reduction in footprint compared to the traditional band-stop filter using L-shaped resonators. The measured results show that the filter has a wide passband of $146.7\;\%$(2.1 GHz to 10.15 GHz) with low insertion loss and the stop band of $10.04\;\%$(5.2 GHz to 5.75 GHz) for 3-dB bandwidth. The measured group delay is less than 0.7 ns within the passband except the rejection band.

자율 다개체 로봇의 작업관리

김동원(Dong W. Kim),정지학(Ji-Hak Jung) 한국정보기술학회 2022 Proceedings of KIIT Conference Vol.2022 No.6

체외수정 시술시 배양액에 첨가된 과립구 대식세포 증식인자 (Granulocyte-Macrophage Colony Stimulating Factor)의 효과

박원일,권혁찬,김동훈,강희규,김묘경,이회창,정지학,이명섭,이호준,Park, Won-Il,Kwon, Hynck-Chan,Kim, Dong-Hoon,Kang, Hee-Kyoo,Kim, Myo-Kyung,Lee, Hoi-Chang,Jung, Ji-Hak,Lee, Myong-Seop,Lee, Ho-Joon 대한생식의학회 2001 Clinical and Experimental Reproductive Medicine Vol.28 No.2

Objective: Granulocyte-macrophage colony stimulating factors known to be secreted in murine and human reproductive tract. The development of human, bovine and murine embryos could be promoted by addition of GM-CSF in culture medium. However, the pregnancy and implantation rate of embryos cultured in GM-CSF have not been evaluated. The aim of this study was to assess the effect of GM-CSF in embryo development, pregnancy and implantation rate. Methods: A total of 191 IVF cycles were divided into control and GM-CSF supplement group (control=96, GM-CSF=95). The embryos were cultured for three day with or without 2 ng/ml of recombinant human GM-CSF. The quality of embryo, developmental velocity, pregnancy and implantation rates were compared. Results: There was no difference in age, number of gonadotropin ampules used, number of oocytes and fertilization. The number of ICSI cycle was higher in GM-CSF group. In GM-CSF group, G-1 grade embryos were the highest in proportion (56.4%), while G-2 grade embryos were highest (44.3%) in control group. The developmental velocity of embryos were not different between GM-CSF and control group. The pregnancy and implantation rates were significantly higher in GM-CSF group than control (47.4% vs. 33.3%, 17.0% vs. 11.1% respectively). Conclusion: By adding GM-CSF in culture medium, the quality of embryo, pregnancy and implantation rate could be improved.

밀리미터파 PHEMT의 도핑층 설계에 따른 특성 변화

박훈(Hoon Park),박진국(Jin-Kuk Park),정지학(Ji-Hak Jung),박현창(Hyun-Chang Park) 대한전자공학회 2000 대한전자공학회 학술대회 Vol.2000 No.6

자궁경관무력증의 임상적 고찰

양윤석(Yun Seok Yang),송치훈(Chi Hun Song),박종호(Jong Ho Park),신정환(Jung Whan Shin),홍서유(Seo Yoo Hong),박미혜(Mi Hye Park),김경진(Kyeng Jin Kim),황인택(In Taek Hwang),정지학(Ji Hak Jung),박준숙(Jun Sook Park) 대한산부인과학회 1999 Obstetrics & Gynecology Science Vol.42 No.2

N/A Objective:Our goal was to evaluate the clinical characteristics and statistical analysis in incompetent internal os of the cervix(IIOC) Method: At Department of Obstetrics and Gynecology, Eulgi Hospital and Eulgi university Hospital from January 1, 1991 to December 31, 1997, 296 cases of IIOC were admitted and treated with McDonald operation or modified Shirodkar operation. Of this, 38cases were follow up lost, so 252 cases were analayzed. Diagnostic criteria was previous history of painless cervical dilatation, followed by spontaneous abortion or preterm birth, and acceptance without resistance at the internal os of No. 8 Hegar dilator. Result: Incidence of IIOC was 1.61%, 1 in 60 deliveries. Most frequent age group was in 28-30 years old group and mean age was 30 years old. Total number and mean number of gravida was 818 and 3.2. The most common contributing factor was previous artificial abortion(77%), and cervix dilatation(9%), old cervical laceration(4.3%) etc, was followed. Operation methods were McDonald operation(56%) and modified Shirodkar operation(44%). The Success rate of McDonald and modified Shirodkar was 78.1% and 88.1%. Successful fetal salvage rate was 82.5%, and the highest success rate was 86.9% in 14-18th weeks of gestation group. The more cervix dilate, the more failure occured. Causes of operation failure was premature rupture of membrane(54.5%), preterm labor(43.2%) and fetal death in utero(2.3%). Delivery method after operation was vaginal delivery(146cases, 70.9%) and cesarean delivery(60cases, 29.1%). Cause of cesarean delivery was previous cesarean section(43.3%), breech presentation(16.7%), cephalopelvic disproportion(15%), prolonged labor(6.7%), fetal disttess(6.7%), twin(5%), placenta previa(3,3%) and abruptio placenta(3.3%). Conclusion: The 14-18th weeks of gestation group & no cervical dilatation group has higher success rate, which indicate early diagnosis and appropriate timing of operation is probably associated with a greater operation