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이주흔(Ju-Heun Lee),김효철(Hyo-Chul Kim),조흥래(Heung-Rae Cho),이덕재(Deok-Jae Lee),안세환(Se-Hwan An),이만희(Man-Hee Lee),주지한(Ji-Han Joo),김홍락(Hong-Rak Kim) 한국정보기술학회 2022 한국정보기술학회논문지 Vol.20 No.2
In this paper, a study was conducted to combining two 100W class SSPA produced by applying a 10W class MMIC T-junction combining and an 8-way binary combiner to manufacture 200W class SSPA. While research on amplifiers for high power and integration in Ka-band satellite communication systems continues, semiconductor-type combining amplifiers SSPA(Solid State Power Amplifier), which are relatively small and easy to maintain, have been studied to replace TWTA(Traveling Wava Tube Amplifier) with warm-up time and high maintenance. SSPA requires low-loss, high-efficiency combining techniques to meet high output because it has lower single device output than TWTA. The SSPA produced in this paper produces 100W class SSPA using an 8-way waveguide binary combiner with a reflection loss of 20㏈ or more and an insertion loss of 1㏈ or less, a 2-way waveguide binary combiner with a reflection loss of 19.9 ㏈ and insertion loss of 0.5 ㏈ or less was applied to fabricate it as a 200W class SSPA.
이주흔(Ju-Heun Lee),윤원상(Won-Sang Yoon),채상훈(Sang-Hoon Chai) 한국정보기술학회 2018 한국정보기술학회논문지 Vol.16 No.10
This paper describes design and fabrication of variable frequency divider IC for RF PLL for ultra wideband communication system using 0.18 ㎛ silicon standard CMOS technology. A frequency divider unit element was designed using super dynamic circuit to obtain high speed low noise characteristics, and a MOSFET switch was used to obtain a variable integer division ratio. In order to solve the limitation problem of the frequency band of the dynamic circuit, changing size of the load resistance used in the frequency divider unit element circuit is applied. The designed circuit was fabricated as a semiconductor IC chip and then measured. As a result, the operating frequency range was in the range of 1 to 7 ㎓ and showed fast and wide frequency band operating characteristics.
P-코어 VCO를 사용한 10.525GHz 자체발진 혼합기의 설계
이주흔(Ju-Heun Lee),채상훈(Sang-Hoon Chai) 한국정보기술학회 2018 한국정보기술학회논문지 Vol.16 No.11
This paper describes design of a 10.525 GHz self oscillating mixer semiconductor IC chip combining voltage controlled oscillator and frequency mixer using silicon CMOS technology for Doppler radar applications. The p-core type VCO included in the self oscillating mixer minimizes the noise contained in the transmitted signal. This noise minimization increases the sensing distance and acts in a direction favorable to the reaching distance and the sensitivity of the motion detection sensor. Simulation results for phase noise show that a VCO designed as a P-core has a noise characteristic of -106.008 dBc / Hz at 1 MHz offset and -140.735 dBc / Hz at 25 MHz offset compared to a VCO designed with N-core and NP-core showed excellent noise characteristics. If a self-oscillating mixer is implemented using a p-core designed VCO in this study, a motion sensor with excellent range and reach sensitivity will be produced.
김효철,조흥래,이주흔,이덕재,안세환,이만희,주지한,권준범,정해창,김소수,Kim, Hyo-Chul,Cho, Heung-Rae,Lee, Ju-Heun,Lee, Deok-Jae,An, Se-Hwan,Lee, Man-Hee,Joo, Ji-Han,Kwon, Jun-Beom,Jeong, Hae-Chang,Kim, So-Su 한국인터넷방송통신학회 2021 한국인터넷방송통신학회 논문지 Vol.21 No.3
초고주파 대역에서 TWTA(Traveling Wave Tube Amplifier)를 대체하기 위한 증폭기 연구가 활발히 이루어지고 있다. 반도체형 소자를 결합하여 높은 출력을 얻는 SSPA(Solid State Power Amplifier)의 경우 상대적으로 낮은 단일 소자의 출력으로 요구 출력을 충족하기 위해서는 저손실, 고효율의 결합 기술이 필요하다. 본 논문을 통해 8-way 도파관 결합기를 설계, 제작하여 20dB 이상의 반사 손실과 85% 이상의 결합 효율을 확인하였다. 전계 분석을 통해 결합기 내부의 임계 전력을 계산하여 안정적인 Power Rating을 확보하였고 전력 모니터링을 위한 커플러를 내장하여 소형화 및 경량화를 이루었다. The research of amplifier have been actively conducted to replace the Traveling Wave Tube Amplifier (TWTA) in the mmWave. For Solid State Power Amplifiers (SSPA), which combine semiconductor-type devices to obtain high output, Low-loss, high-efficiency combination techniques are required to meet the required output as the output of a single relatively low device is relatively low. In this paper, we design and produce an 8-way waveguide combiner and a reflective loss of more than 20dB and a binding efficiency of 85% or more were identified. Field analysis calculates the critical power inside the combiner. It secured stable Power Ratings and built-in coupler for power monitoring to achieve miniaturization and light weight.
TM<sub>01</sub> 모드 변환을 이용한 Ka 대역 고출력 고효율 공간 결합기 설계 및 제작
김효철,조흥래,이주흔,이덕재,안세환,이만희,주지한,김홍락,Kim, Hyo-Chul,Cho, Heung-Rae,Lee, Ju-Heun,Lee, Deok-Jae,An, Se-Hwan,Lee, Man-Hee,Joo, Ji-Han,Kim, Hong-Rak 한국인터넷방송통신학회 2021 한국인터넷방송통신학회 논문지 Vol.21 No.6
본 논문에서는 비교적 구현이 쉽고, 최종 결합 포트의 전송 선로 길이를 짧게 구현할 수 있는 모드 변환기에 대해 제안하고, 8-way 공간 결합기에 적용하여 제작 및 시험을 하였다. 제안하는 모드 변환기는 그라운드와 연결되어 있는 Doorknob 형태의 원형 디스크에서 변환된 신호를 원형 도파관 내에서 개방을 시켜 TM<sub>01</sub> 모드로 변환이 이루어진다. 8-way 도파관 공간 결합기는 H-평면에서 입력된 8개의 신호를 중심의 원형 도파관에서 결합이 이루어지고, 최종 결합 모드는 TM<sub>01</sub>이 되도록 설계를 하였다. 시험 결과는 삽입손실 0.4dB 이하, 결합효율 95%이상의 우수한 성능을 확인하였다. 또한 전계 분석을 통해 새로운 모드 변환 구조의 절연 파괴 전압 및 방전 임계전력을 계산하여 고출력에 적합함을 확인하였다. 본 연구를 통해 확인된 결과는 향후 고출력 고효율 SSPA에 다방면으로 적용이 가능할 것으로 기대된다. In this study, it proposes a mode converter that is relatively easy to implement and can shorten the transmission line length of the final combining port and it was fabricated and tested by applying it to an 8-way spatial combiner. The proposed mode converter converts the signal converted from the doorknob-shaped circular disk connected to the ground into the TM<sub>01</sub> mode by opening it in the circular waveguide. The 8-way waveguide spatial combiner is designed and implemented so that 8 signals input from the H-plane are combined in a circular waveguide at the center, and the final combining mode is TM<sub>01</sub>. The test results confirmed excellent performance with an insertion loss of less than 0.4dB and a combining efficiency of 95% or more. In addition, it was confirmed that it is suitable for high output by calculating the breakdown voltage and discharge threshold power of the new mode conversion structure through electric field analysis. The results confirmed through this study are expected to be applicable to high-power, high-efficiency SSPA in various fields in the future.
Ka 대역 고출력 고효율 도파관 공간 결합기 설계 및 제작
김효철,조흥래,이주흔,이덕재,안세환,이만희,주지한,김홍락,Kim, Hyo-Chul,Cho, Heung-Rae,Lee, Ju-Heun,Lee, Deok-Jae,An, Se-Hwan,Lee, Man-Hee,Joo, Ji-Han,Kim, Hong-Rak 한국인터넷방송통신학회 2021 한국인터넷방송통신학회 논문지 Vol.21 No.5
본 논문에서는 고출력 저손실의 도파관 공간결합 구조를 제안하였다. 제안하는 공간결합구조는 각 포트의 중심에서 원형 도파관을 통해 결합하는 방식으로 구현 하였다. 특히 도파관의 모드 중 전송 선로 손실이 가장 적은 TE01모드를 이용하여 저 손실을 구현하고, 새로운 모드 변환 방식을 적용하여 소형화를 이루었다. 또한 전계 분석을 통해 새로운 모드 변환 구조의 절연 파괴 전압을 계산하여 고출력에 적합함을 확인하였다. 최종 8-way 도파관 공간 결합기를 설계, 제작하여 삽입 손실은 0.4dB 이하 결합효율 97% 이상의 결과를 얻어 평면 결합 방식 대비 전기적 성능이 매우 우수함을 확인하였다. This report proposes a waveguide spatial combiner with high power low loss. The proposed spatial combiner implements high power by combining from the center of each port through a waveguide. In particular, we implement low loss using TE01 mode, which has the lowest transmission track loss among modes of circular waveguide, and miniaturization is achieved by applying a new mode conversion method. IIn addition, it was confirmed that it was suitable for high output by calculating the insulation breakdown voltage of the new mode conversion structure through E-field analysis. The final 8-way waveguide spatial combiner was designed and manufactured, and the insertion loss was less than 0.4dB and the combining efficiency was 97% or more, confirming that the electrical performance was very good compared to the planar combining method.
비대칭 개구면 결합 급전을 이용한 원형편파 마이크로스트립 패치 안테나 설계
홍민철(Min-Cheol Hong),이주흔(Ju-Heun Lee),오정택(Jeong-Taek Oh),윤원상(Won-Sang Yoon) 한국정보기술학회 2018 한국정보기술학회논문지 Vol.16 No.6
A circularly polarized(CP) aperture coupled microstrip antenna with an asymmetric aperture is introduced in this paper. The proposed antenna consists of a lower substrate including a feeder line and a ground plane with an aperture and an upper substrate with a patch. Two orthogonal degenerated mode is induced on the patch due to the asymmetric aperture on the ground and air gap between ground plane and upper substrate is utilized to enhance the bandwidth for the proposed antenna. For validation of proposed CP antenna, we design and fabricate the prototype with right handed circular polarization over 2.45GHz band. From the experimental results, the proposed antenna has impedance bandwidth of 160MHz(2.41 ~ 2.57GHz), the CP bandwidths of 40MHz(2.45 ~ 2.49GHz), and the peak gain of 8.37dBi.
X-band 레이더 응용을 위한 개구면 결합 급전 마이크로스트립 배열 안테나 설계
윤원상(Won-Sang Yoon),홍민철(Min-Cheol Hong),이주흔(Ju-Heun Lee) 한국정보기술학회 2017 한국정보기술학회논문지 Vol.15 No.4
In this paper, an aperture coupled microstrip array antenna applicable to X-band radar systems is described. Eight unit radiators and a 8-way Wilkinson divider consist of the proposed array antenna. The unit radiator is composed by two stacked substrates using common ground plane with aperture slot and two rectangular patches and feeding network using T-junction divider is etched on each substrates. Two substrates including two patches and feeder network are bonded using a prepreg for obtaining solid structure. From the experimental results, the fabricated array antenna has an impedance bandwidth of 9.19~9.78GHz and a maximum gain of 14.7dBi in the operating band. Also, the 3dB beamwidth is measured 12.5° at 9.35GHz.