• ETRI Journal
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• v.41 no.2
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• pp.262-269
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• 2019

This paper introduces a low-cost, high-performance mmWave antenna array module at 77 GHz. Conventional waveguide transitions have been replaced by 3D CPW-microstrip transitions which are much simpler to realize. They are compatible with low-cost substrate fabrication processes, allowing easy integration of ICs in 3D multi-chip modules. An antenna array is designed and implemented using multilayer coupled-fed patch antenna technology. The proposed $16{\times}16$ array antenna has a fractional bandwidth of 8.4% (6.5 GHz) and a 23.6-dBi realized gain at 77 GHz.

• ETRI Journal
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• v.32 no.5
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• pp.827-830
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• 2010

For an adaptive cruise control (ACC) stop-and-go system in automotive applications, three radar sensors are needed because two 24 GHz short range radars are used for object detection in an adjacent lane, and one 77 GHz long-range radar is used for object detection in the center lane. In this letter, we propose a single sensor-based 24 GHz radar with a detection capability of up to 150 m and ${\pm}30^{\circ}$ for an ACC stop-and-go system. The developed radar is highly integrated with a high gain patch antenna, four channel receivers with GaAs RF ICs, and back-end processing board with subspace based digital beam forming algorithm.

• IEIE Transactions on Smart Processing and Computing
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• v.4 no.4
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• pp.258-264
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• 2015

The first 77 GHz transceiver that applies a heterodyne structure-based linear frequency modulation-frequency shift keying (LFM-FSK) front-end module (FEM) is presented. An LFM-FSK waveform generator is proposed for the transceiver design to avoid ghost target detection in a multi-target environment. This FEM consists of three parts: a frequency synthesizer, a 77 GHz up/down converter, and a baseband block. The purpose of the FEM is to make an appropriate beat frequency, which will be the key to solving problems in the digital signal processor (DSP). This paper mainly focuses on the most challenging tasks, including generating and conveying the correct transmission waveform in the 77 GHz frequency band to the DSP. A synthesizer test confirmed that the developed module for the signal generator of the LFM-FSK can produce an adequate transmission signal. Additionally, a loop back test confirmed that the output frequency of this module works well. This development will contribute to future progress in integrating a radar module for multi-target detection. By using the LFM-FSK waveform method, this radar transceiver is expected to provide multi-target detection, in contrast to the existing method.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.553-554
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• 2006

In this paper, 77 GHz CPW power amplifier MMIC, which are consisted of a 2 stage driver stage and a power stage employing $8{\times}50um$ gate width, have been successfully developed by using 120nm $In_{0.4}AlAs/In_{0.35}GaAs$ Metamorphic high electron mobility transistors (MHEMTs). The devices show an extrinsic transconductance $g_m$ of 660 mS/mm, a maximum drain current of 700 mA/mm, and a gate drain breakdown voltage of -8.5 V. A cut-off frequency ($f_T$) of 172 GHz and a maximum oscillation frequency ($f_{max}$) of over 300 GHz are achieved. The fabricated PA exhibited high power gain of 20dB only with 3 stages. The output power is measured to be 12.5 dBm.

• Journal of electromagnetic engineering and science
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• v.9 no.4
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• pp.218-222
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• 2009

In this paper, we present a CPW-based 77 GHz 3-stage power amplifier MMIC for automotive radar systems. The power amplifier MMIC has been realized using a 130 nm $In_{0.88}$GaP/$In_{0.4}$AlAs/$In_{0.4}$GaAs metamorphic high-electron mobility transistors(mHEMTs) technology and an output stage with a cascode configuration. This produced a good output power and gain performance at 77 GHz. The fabricated power amplifier MMIC exhibited a small-signal gain of 18 dB, an output power of 17 dBm and 9 % power added efficiency(PAE) at 77 GHz with a total gate width of 800 ${\mu}m$ in the output stage. These performances could be useful to low-cost and small-sized components for 77 GHz automotive radar systems.

• Journal of Satellite, Information and Communications
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• v.9 no.3
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• pp.53-58
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• 2014

The global automotive radar is regulated to use the 22GHz~26GHz band. However, it plans to move to the 77~81GHz band of a broadband radar in the millimeter wave for the high resolution of pedestrian sensing and blind spot. On the other hand, the 71~275GHz band is regulated to use a radio astronomy service. The interference is predicted between an automotive radar and a radio astronomy service. Therefore, this paper analyzed the interference impact of the automotive radar on the radio astronomy service and then obtained separation distance for the protection of the radio astronomy service.

• JSTS:Journal of Semiconductor Technology and Science
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• v.16 no.5
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• pp.650-656
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• 2016

Voltage controlled oscillator (VCO) is widely used circuit component in high-performance microprocessors and modern communication systems as a frequency source. In present work, VCO designs using the different combination of NAND gates with three transistors and CMOS inverter are reported. Three, five and seven stages ring VCO circuits are designed. Coarse and fine tuning have been done using two different supply sources. The frequency with coarse tuning varies from 3.31 GHz to 5.60 GHz in three stages, 1.77 GHz to 3.26 GHz in five stages and 1.27 GHz to 2.32 GHz in seven stages VCO respectively. Moreover, for fine tuning frequency varies from 3.70 GHz to 3.94 GHz in three stages, 2.04 GHz to 2.18 GHz in five stages and 1.43 GHz to 1.58 GHz in seven stages VCO respectively. Results of power consumption and phase noise for the VCO circuits are also been reported. Results of proposed VCO circuits have been compared with previously reported circuits and present circuit approach show significant improvement.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.10
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• pp.41-49
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• 2013

This paper suggests the dielectric resonator antenna using LTCC process for mm-wave car radar system. In this paper, dielectric resonator antennas (DRA) operated in 76-77 GHz frequency band are designed. And, using the LTCC process, the structures of dielectric resonator with SRR (split ring resonator) inside and those of dielectric resonator with probe inside are suggested. Linear polarization antennas and circular polarization antenna are designed for the DRA with probe inside. Three kinds of the DRA antennas are designed and their characteristics are calculated using CST RF simulation tool. The designed antennas are fabricated and measured and the measured results are compared with calculated results. The measured operating frequencies of DRAs are within 76 GHz to 77 GHz, which are close to the calculated results, and the measured gains are about 8.15 dBi to 10.82 dBi.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2000.11a
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• pp.377-380
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• 2000

본 논문에서는 개구 결합 방식의 마이크로스트립 안테나에 U 슬롯과 turning stub를 동시에 사용하여 넓은 대역폭을 갖는 안테나를 설계 및 제작하였다. 상대 유전율이 2.2이고 두께가 61mil인 duroid 5880기판을 사용하여 ITS(Intelligent Transport System)대역인 5.77GHz에서 동작하는 안테나를 설계하였고, VSWR$\leq$2를 기준으로 하여 약 12.4%의 대역폭을 얻을 수 있었다. 그리고 약 7GHz에서 동작하는 안테나에서는 상대 유전율이 2.2이고 두께가 31mil인 5880기판과 1.6mm인 form을 사용하여 VSWR$\leq$1.5를 기준으로 약 11.7%의 대역폭을 얻을 수 있었다. 각각의 경우 U 슬롯만을 사용한 경우와 비교할 때 5.77 GHz에서는 5.7% 7GHz대역에서는 약 4%의 대역폭 개선 효과를 확인할 수 있었다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.30 no.2
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• pp.152-159
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• 2019

In general, a Doppler radar can measure only the velocity of a moving target. To measure the distance of a moving target, it is necessary to use a frequency-modulated continuous wave or pulse radar. However, the latter are very complex in terms of both hardware as well as signal processing. Moreover, the requirement of wide bandwidth necessitates the use of millimeter-wave frequency bands of 24 GHz and 77 GHz. Recently, a new kind of Doppler radar using multitone frequency has been studied to sense the distance of moving targets in addition to their speed. In this study, we show that distance sensing of moving targets is possible by adjusting only the frequency of a 2.4 GHz Doppler radar with low cost phase lock loop. In particular, we show that distance can be sensed using only alternating current information without direct current offset information. The proposed technology satisfies the Korean local standard for low power radio equipment for moving target identification in the 2.4 GHz frequency band, and enables multiple long-range sensing and radio-frequency identification applications.