Phased Array Antenna Using Active Device

Seo, Chul-Hun The Korean Institute of Electrical Engineers 2004 KIEE International Transactions on Electrophysics Vol.4C No.6

This paper presents a new active antenna consisting of a microstrip patch for the passive radiator, a mixer for frequency conversion, a voltage controlled oscillator (VCO) and a phase detector for phase control. The microwave signal frequency has been converted into intermediate frequency (IF) on the antenna elements by the mixer. The active antenna consists of two ports, the IF port has a transmitted IF signal via power combined to the baseband and the dc control port is under the control of the phase-detector. The input voltage of the VCO is controlled by the phase detector. The scan range of the array is determined by the phase detector and the VCO and is obtained between 30$^{\circ}$ and - 30$^{\circ}$

300-GHz Integrated Heterodyne Receiver Chain for Phased-Array with Wide IF Bandwidth

박건우,이승종,한인수,전상근 한국과학기술원 반도체설계교육센터 2021 IDEC Journal of Integrated Circuits and Systems Vol.7 No.4

This paper presents a fully integrated terahertz receiver chain for phased-array with a wide IF bandwidth designed using a 250-nm InP double heterojunction bipolar transistor (DHBT) technology. The phased-array receiver chain consists of a variable-gain low-noise amplifier (VG-LNA), phase shifter, down-conversion mixer, and injection locking local oscillator (ILO). Each circuit block is designed to be broadband to achieve a wide receiver chain bandwidth. The VG-LNA adopts cascaded amplifying stages with a current steering technique to control the gain. While the control voltage (Vcon) varies from 2 to 3.6 V, the gain varies from 15.6 to 0 dB at 300 GHz. The noise figure is no higher than 15 dB at all Vcon conditions. The phase shifter uses a current combining structure based on Gilbert cells. The peak conversion gain is -10 dB at 303 GHz and the 3 dB bandwidth is 52 GHz extending from 270 to 322 GHz. The LO employs an injection locking technique. The locking range is from 260 to 328 GHz (22.7%) when a 10-dBm signal is injected. The maximum output power is 0.5 dBm at 300 GHz. The Gilbert-cell-based down-conversion mixer shows a 72-GHz bandwidth extending from 252 GHz to 324 GHz. The proposed fully integrated phased-array receiver chain shows a wide bandwidth characteristic. When the control voltage is set to 2.0 V, the peak conversion gain is 12.3 dB and the 3-dB bandwidth reaches 45 GHz from 270 GHz to 315 GHz.

능동 역지향성 배열 안테나용 공액 위상변위기

전중창,정덕수,이병로,탁한호,Chun Joong-Chang,Jeung Deuk-Soo,Lee Byung-Rho,Tack Han-Ho 한국전자파학회 2005 한국전자파학회논문지 Vol.16 No.2

본 논문에서는 능동 역지향성 배열 안테나용의 마이크로파 공액 위상변위기에 관한 새로운 구조를 제안하였다. 본 논문에서 제안된 공액 위상변위기는 Single-Balanced 혼합기를 응용한 것으로, 일반적인 혼합기와 달리, LO 및 RF 신호의 결합과 임피던스 매칭의 복잡성을 줄이기 위해서 2-포트 구조를 채택하였으며, 병렬 연결된 두 개의 Single-Ended 혼합기에 180도 위상반전 회로를 삽입하여, 공액 위상변위기 설계에서 가장 큰 문제가 되는 IF 출력단의 RF 누설성분을 억제하였다. 동작 주파수는 LO 4 GHz, RF 2.01 GHz, IF 1.99 GHz이다. 제작된 공액 위상변위기는 9 dBm의 LO전력에서 변환손실은 -7 dB, 1-dB 억압점 15 dBm의 특성을 보인다. 공액 위상 변위기의 가장 중요한 파라미터인 RF/IF 격리도는 25 dB에 달한다. In this paper, we have developed a new type of the microwave phase conjugator for the active retrodirective antenna array. The circuit topology is consisted of a 2-port structure to avoid the complexity of LO and RF signal combination and matching, using the cascade connection of two single-ended mixers. The operating frequencies are 4.0 GHz, 2.01 GHz and 1.99 GHz for LO, RF, and IF, respectively. Conversion loss is measured to be -7 dB and 1-dB compression point 15 dBm with the LO power of 9 dBm. For the most important parameter, the isolation between RE leakage and IF signal is as high as 25 dB.

다상유동해석을 이용한 파일롯규모 혼합확산장치의 운영인자 도출에 관한 연구

오대민(Daemin Oh) 대한환경공학회 2018 대한환경공학회지 Vol.40 No.8

본 연구의 목적은 녹조발생으로 인한 호소의 부영양화를 최소화하기 위해 설치하고 있는 혼합확산장치 임펠러를 실제 호소에 적용하기 위해 파일롯 규모의 혼합확산장치를 개발함에 앞서 임펠러 운전으로 인한 혼합확산영향에 대한 운영인자를 도출하고자 한다. 본 연구대상 혼합확산장치 임펠러는 하부의 물을 상승시키고 수표면에서 Jet흐름에 의한 대기접촉 및 물표면으로 확산하는 기능을 가지고 있으며 직경 700 mm로 제작된다. 다상유동해석기법을 적용하여 정상상태 조건에서 임펠러의 운전특성을 예측하고 비정상상태 조건으로 영향반경을 예측하였다. 임펠러의 최대속도는 약 6.78 m/s로 나타났으며, 임펠러에 의해 발생하는 자유표면의 높이와 속도벡터는 날개의 압력면에서 수위상승과 흡입면에서 수위가 하강하는 것으로 나타났다. 토출량은 회전수에 정비례하였고 모드전환에 따른 토출량 및 에너지효율은 거의 동일하였다. 또한, 혼합확산장치 운전 후 3분후에는 40 m의 영향반경을 나타냈고 13분 경과 후 자유표면에서 약 90 m 확산되며, 자유표면 하부에서는 약 40 m까지 영향반경이 확대되는 것으로 나타났다. The purpose of this study was to derive operational parameters by predicting the effect of mixed diffusion by operating the pilot-scale device’s impeller applied to the actual lake. This device is installed to prevent the eutrophication of the reservoir due to the occurrence of algae. The diffusion mixer’s impeller of this study has the function of raising the lower water and diffusing to the atmospheric contact and water surface by the jet flow at the water surface, and it is manufactured with a diameter of 700 mm. In this study, the multi-phase flow analysis technique was applied and the operating characteristics of the impeller were predicted under the steady state conditions and the influence radius was predicted under the un-steady condition. The maximum velocity of the impeller was about 6.78 m/s. The height and velocity vector of the free surface generated by the impeller showed a increase in the pressure level of the wing and a decrease in the water level on the suction side. The discharge flow rate was directly proportional to rpm, and the discharge amount and energy efficiency of the mode conversion were the same. Also, after 3 minutes from the operation of the water circulator, the radius of influence was 40 m. After 13 minutes, the free surface was spread about 90 m and the radius of influence was increased to about 40 m below the free surface.

전자기파 반사 감소를 위한 역지향 배열 안테나 시스템

하정제(Jungje Ha),장성훈(Sunghoon Jang),이용식(Yongshik Lee) 한국전자파학회 2015 한국전자파학회논문지 Vol.26 No.1

본 논문에서는 병렬 믹서 구조의 역지향 배열 안테나 시스템을 제안하고, 이를 능동 상쇄에 적용하였다. 주파수 체배기를 이용해 입사 신호의 두 배 주파수를 발생시켜 국부 발진 신호로 활용함으로써 임의의 주파수에서 위상 공액 특성을 자동적으로 얻을 수 있다. 이러한 특성의 제안된 시스템은 전자기파가 입사할 경우 입사 방향뿐만 아니라 주파수에 대한 사전 지식이 없더라도 입사 방향으로 상쇄 신호를 송신할 수 있으므로 능동 상쇄를 위해 활용될 수 있다. 또한, 병렬믹서 구조를 통해서 주파수가 동일한 믹서의 입출력 신호 사이의 높은 격리도를 확보함으로써 정확한 입사 신호 방향으로 송신 신호를 발생 시킬 수 있다. 실험적 검증을 위해서 병렬 믹서 방식의 2×2 역지향 배열 안테나 시스템을 설계, 제작하여 금속성 원통에 대한 반사파 상쇄 실험을 수행하였다. 제안된 시스템 적용 후 반사 신호의 크기가 최대 26 dB까지 감소되는 결과를 통해 제안된 방법의 유효성을 확인하였다. In this paper, a cancellation technique for electromagnetic waves is realized based on a retrodirective antenna array system. The system re-transmits a signal to the direction of the incoming signal, with the same frequency and opposite phase. For the experimental verification, a 2×2 retrodirective array system is designed and fabricated. Experimental results for a metallic cylinder show as much as 26-dB reduction in reflection.

위상주파수 검출기를 이용한 주파수 잠금회로

임평순(Pyung-Soon Im),이동현(Dong-Hyun Lee),염경환(Kyung-Whan Yeom) 한국전자파학회 2017 한국전자파학회논문지 Vol.28 No.7

논리회로로 구성된 위상주파수 검출기(Phase Frequency Detector: PFD)는 집적회로 구현의 용이성으로 인해 위상잠금회로(Phase Locked Loop: PLL)에 널리 사용되고 있다. 반면, 주파수 잠금회로(Frequency Locked Loop: FLL)는 PLL에서 기준발진기를 제거하고 공진기가 기준발진기 역할을 하는 구성이다. FLL 구성에는 주파수 검출기(Frequency Detector: FD)가 반드시 필요하며, 통상적으로 혼합기(mixer)로 구성된 주파수 검출기를 이용한 FLL을 구성하게 된다. 본 논문에서는 혼합기를 이용한 FD대신에, PFD의 범용성을 고려하여, 마이크로스트립으로 구성된 1.175 ㎓ 공진기와 PFD를 이용하여 FD를 구성하였다. 또한 설계된 FD를 이용 주파수 1.175 ㎓에서 발진하는 FLL을 구성하였다. 혼합기(mixer)를 이용한 FD로 구성된 FLL과 비교결과 제안된 FLL은 FLL 대역 내에서 혼합기 FD를 이용한 FLL에 비하여 위상잡음 성능이 우수한 것을 확인하였다. A phase frequency detector(PFD) composed of logic circuits is widely used in a phase locked loop(PLL) due to the easy implementation for integrated circuits. A frequency locked loop(FLL) removes the reference oscillator in the PLL, and the resonator serves as a reference oscillator. A frequency detector(FD) is indispensable for the FLL configuration, and a FD, which is usually composed of a mixer is used to build an FLL. In this paper, instead of FD using mixer, a FD is constructed by using 1.175 ㎓ resonator composed of microstrip and PFD taking the versatility of PFD into consideration. Using the designed FD, FLL oscillating at a frequency of 1.175 ㎓ is composed. As a result of comparison with the FLL composed of FD using mixer, it was confirmed that the proposed FLL has better phase noise performance than FLL using mixer FD with FLL bandwidth.

Design and Analysis of Multi Beam Space Optical Mixer

Lian Guan,Zheng Yang 한국광학회 2024 Current Optics and Photonics Vol.8 No.1

In response to the current situation where general methods cannot effectively compensate for the phase delay of ordinary optical mixers, a multi-layer spatial beam-splitting optical mixer is designed using total reflection triangular prisms and polarization beam splittings (PBS). The phase delay is generated by the wave plate, and the mixer can use the existing parallel plates in the structure to individually compensate for the phase of the four output beams. A mixer model is established based on the structure, and the influence of the position and orientation of the optical components on the phase delay is analyzed. The feasibility of the phase compensation method is simulated and analyzed. The results show that the mixer can effectively compensate for the four outputs of the optical mixer over a wide range. The mixer has a compact structure, good performance, and significant advantages in phase error control, production, and tuning, making it suitable for free-space coherent optical communication systems.

Experimental study of gas-liquid two-phase bubbly flow characteristics in a static mixer with three twisted leaves

Huibo Meng,Yuning Hao,Yanfang Yu,Zhonggen Li,Shuning Song,Jianhua Wu 한국화학공학회 2020 Korean Journal of Chemical Engineering Vol.37 No.11

Under the conditions of liquid phase inlet Re ranging from 9,836 to 56,206 and gas fraction α from 4.76% to 66.67%, gas-liquid two-phase bubbly flow was investigated in a static mixer with three twisted leaves (TKSM) with a diameter of 100mm and an aspect ratio of 1.5. A high-speed camera Revealer-2F04M with a resolution of 1,920×1,080 pixels was used to capture the evolution of bubble groups at the different axial windows of mixer elements. The results show that the flow pattern in the TKSM is still in bubbly flow at the flow rate of continuous phase QL no more than 1.0 m3/h and gas fraction α higher up to 54.55%-66.67%. The Sauter mean diameter d32 of bubble groups gradually decreased with the increase of the mixing elements number. With the given liquid flow rate QL1.0m3/h, the Sauter mean diameter d32 firstly decreased and then increased with the increase of gas flow rate. The local minimum of d32 was obtained at QG=0.72m3/h and 84.5% of the dB/D0 is in the range of 0.02-0.05. The relationship among Sauter mean diameter, the inner diameter and the non-dimensional residence time  satisfies the correlation We0.35·d32/D0=0.026 0.17.

산업용 교반기의 고체-액체 혼합에 대한 Eulerian Two-Phase 유동해석

송애경(Aekyung Song),허남건(Nahmkeon Hur),원찬식(Chan-Shik Won),안익진(Ickjin Ahn) 한국유체기계학회 2006 유체기계 연구개발 발표회 논문집 Vol.- No.-

The Mixer is apparatus that help precipitation or an inhomogeneous distribution of various phases to be mixed and that user makes necessary material mixing one or the other. Mainly the mixer which is used from chemical and food industry is very important system in engineering that mixes the material. The inside flow of the mixer under the actual states which put a basis in flow of the fluid is formed rotation of the impeller. The inside flow of impeller will be caused by various reasons change with shape of impeller, number of rotation, mixing material and flow pattern of free surface etc. Also mixer study depended in single-phase flow and experimental research. So the numerical analysis of flow mixing solid-fluid particle is simulated. It is become known, that the case where agitator inside working fluid includes the solid particle the sinkage reverse which the solid particle has decreases an agitation efficiency. From the research which it sees the hazard solid which examines the effect where the change of the sinkage territory which it follows agitation number of revolution and diameter of the particle goes mad to an agitator inside flow distribution - numerical analysis the inside flow distribution of liquid state with Eulerian Two-Phase Method.

A Differential Voltage-controlled Oscillator as a Single-balanced Mixer

Nam-Jin Oh 한국인터넷방송통신학회 2021 Journal of Advanced Smart Convergence Vol.10 No.1

This paper proposes a low power radio frequency receiver front-end where, in a single stage, singlebalanced mixer and voltage-controlled oscillator are stacked on top of low noise amplifier and re-use the dc current to reduce the power consumption. In the proposed topology, the voltage-controlled oscillator itself plays the dual role of oscillator and mixer by exploiting a series inductor-capacitor network. Using a 65 nm complementary metal oxide semiconductor technology, the proposed radio frequency front-end is designed and simulated. Oscillating at around 2.4 GHz frequency band, the voltage-controlled oscillator of the proposed radio frequency front-end achieves the phase noise of ‒72 dBc/Hz, ‒93 dBc/Hz, and ‒113 dBc/Hz at 10KHz, 100KHz, and 1 MHz offset frequency, respectively. The simulated voltage conversion gain is about 25 dB. The double-side band noise figure is ‒14.2 dB, ‒8.8 dB, and ‒7.3 dB at 100 KHz, 1 MHz and 10 MHz offset. The radio frequency front-end consumes only 96 μW dc power from a 1-V supply.