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Hong-Teuk Kim

Bio: Hong-Teuk Kim is an academic researcher from LG Electronics. The author has contributed to research in topics: CMOS & Amplifier. The author has an hindex of 28, co-authored 71 publications receiving 1869 citations. Previous affiliations of Hong-Teuk Kim include Seoul National University & KAIST.


Papers
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Journal ArticleDOI
TL;DR: This paper describes a 28-GHz CMOS direct conversion transceiver with packaged patch antenna array for 5G communication with well-fit beam control capability with low error vector magnitude.
Abstract: This paper describes a 28-GHz CMOS direct conversion transceiver with packaged $2 \times 4$ patch antenna array for 5G communication. Beamforming antenna and reconfigurable transceiver architecture are used for high effective isotropic radiated power (EIRP). For low error vector magnitude (EVM), switchless matching transmitter (Tx)/receiver (Rx) to antenna and 28-GHz injection-locked local oscillator (LO) generator are employed. Test chip was fabricated in 28-nm RF CMOS process. Measurement results show Tx EIRPsat of 31.5 dBm ( $P_{\mathrm {sat}}$ of 10.5 dBm in one power amplifier (PA)), EIRPmax 24 dBm ( $P_{\mathrm {max}}$ of 2 dBm with backoff of 7.5 dB in one PA), Rx noise figure of 6.7 dB, and integrated LO phase noise of −38.7 dBc (0.67°). After IQ mismatch calibration, Tx LO leakage and image power are less than −35 dBc. Rx and Tx EVM show 2.2% (−33 dB) at medium RF power (Rx $P_{\mathrm {in}}$ of −60 dBm and Tx EIRP of 0 dBm) with well-fit beam control capability.

180 citations

Journal ArticleDOI
TL;DR: An IM2 distortion cancellation technique exploiting the complementary RF performance of NMOS and PMOS while retaining thermal noise canceling is adopted in the LNA, achieving a low noise figure and high IIP3.
Abstract: A wideband CMOS low noise amplifier (LNA) with single-ended input and output employing noise and IM2 distortion cancellation for a digital terrestrial and cable TV tuner is presented. By adopting a noise canceling structure combining a common source amplifier and a common gate amplifier by current amplification, the LNA obtains a low noise figure and high IIP3. IIP2 as well as IIP3 of the LNA is important in broadband systems, especially digital terrestrial and cable TV applications. Accordingly, in order to overcome the poor IIP2 performance of conventional LNAs with single-ended input and output and avoid the use of external and bulky passive transformers along with high sensitivity, an IM2 distortion cancellation technique exploiting the complementary RF performance of NMOS and PMOS while retaining thermal noise canceling is adopted in the LNA. The proposed LNA is implemented in a 0.18 mum CMOS process and achieves a power gain of 14 dB, an average noise figure of 3 dB, an IIP3 of 3 dBm, an IIP2 of 44 dBm at maximum gain, and S11 of under -9 dB in a frequency range from 50 MHz to 880 MHz. The power consumption is 34.8 mW at 2.2 V and the chip area is 0.16 mm2.

140 citations

Journal ArticleDOI
TL;DR: In this article, a low-loss digital distributed phase shifters using micromachined capacitive shunt switches for V-band applications was developed using high-Q metal-air-metal capacitors in series with the microelectromechanical system (MEMS) shunt capacitive switches to minimize the dielectric loss.
Abstract: Low-loss digital distributed phase shifters have been developed using micromachined capacitive shunt switches for V-band applications. Instead or conventional metal-insulator-metal capacitors, high-Q metal-air-metal capacitors were used in series with the microelectromechanical system (MEMS) shunt capacitive switches to minimize the dielectric loss. The operation voltage for the phase shifters was also reduced by applying the bias directly to the MEMS shunt switches through choke spiral inductors. Fabricated 2-b (270/spl deg/) and 4-b (337.5/spl deg/) distributed phase shifters showed low average insertion losses of 2.2 dB at 60 GHz and 2.8 dB at 65 GHz, respectively. The average phase errors for 2-b and 4-b phase shifters were 6.5% and 1.3%, respectively. The return losses are better than 10 dB over a wide frequency range from 40 to 70 GHz. Most of the circuits operated at 15-35-V bias voltages. These phase shifters present promising solution to low-loss integrated phase shifting devices at the V-band and above.

100 citations

Proceedings ArticleDOI
04 Jun 2017
TL;DR: In this article, a 28GHz direct conversion transceiver with packaged 2×4 patch antenna arrays for 5G communication is described, and the authors show good RF performances of Rx NF 6.7dB, Maximum Tx EIRP 31.5dBm, LO integrated phase noise −37.8dBc (0.67°), Rx/Tx EVM around 2.2% (−33.1dB) at mid RF power, and well-fitted beam control capability.
Abstract: This paper describes a 28GHz CMOS direct conversion transceiver with packaged 2×4 patch antenna arrays for 5G communication. Test results show good RF performances of Rx NF 6.7dB, Maximum Tx EIRP 31.5dBm (1PA P out_sat =10.5dBm), LO integrated phase noise −37.8dBc (0.67°), Rx/Tx EVM around 2.2% (−33.1dB) at mid RF power, and well-fitted beam control capability.

95 citations

Journal ArticleDOI
TL;DR: In this paper, the silver-coated nano-particle LiMn 2 O 4 showed excellent cycleability at 2C galvanostatic conditions. But the results indicate that such surface treatment of cathode powders should be an effective way to improve cycle-life with high current retention.

81 citations


Cited by
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Journal ArticleDOI
TL;DR: In this article, the authors provide an overview of strategies for powering MEMS via non-regenerative and regenerative power supplies, along with recent advancements, and discuss future trends and applications for piezoelectric energy harvesting technology.
Abstract: Power consumption is forecast by the International Technology Roadmap of Semiconductors (ITRS) to pose long-term technical challenges for the semiconductor industry. The purpose of this paper is threefold: (1) to provide an overview of strategies for powering MEMS via non-regenerative and regenerative power supplies; (2) to review the fundamentals of piezoelectric energy harvesting, along with recent advancements, and (3) to discuss future trends and applications for piezoelectric energy harvesting technology. The paper concludes with a discussion of research needs that are critical for the enhancement of piezoelectric energy harvesting devices.

1,151 citations

Journal ArticleDOI
TL;DR: In this article, the surface of cathode materials including LiCoO2, LiNiO2 and LiMn2O4 was coated with oxides such as MgO, Al2O3, SiO 2, TiO 2, ZnO, SnO 2 O 2, Li2O·2B2O 3-glass and other materials.

558 citations

Journal ArticleDOI
TL;DR: The recent progress in MEMS for radio frequency (RF) applications from a device perspective is reviewed in this article, where switches and relays, tunable capacitors, integrated inductors, mechanical resonators and filters, and some representative microwave and millimetre-wave components are discussed.
Abstract: This paper reviews the recent progress in MEMS for radio frequency (RF) applications from a device perspective. RF MEMS devices reviewed include switches and relays, tunable capacitors, integrated inductors, mechanical resonators and filters, and some representative microwave and millimetre-wave components. Important device parameters are highlighted, as they have significant contributions to the performance of the final products in which the devices are used. The challenges and statuses of these RF MEMS devices are outlined and discussed. The intent of this topical review is to provide perspective to newcomers in the field, and empower potential end-users with an overall device picture, current status, and a vision of their ultimate performance capabilities.

552 citations

Journal ArticleDOI
TL;DR: In this article, the authors present an overview of the causes and the relative magnitudes of stresses in the various electrode materials, highlights some of the more recent discoveries concerning the causes (such as stress development due to passivation layer formation), introduces the recently developed techniques for in situ observations of lithiation induced deformations and measurement of stresses, analyses the strategies adopted for addressing the stress-related issues, and raises various issues that still need to be addressed to overcome the stress related problems.

494 citations

Journal ArticleDOI
TL;DR: In this article, the physical, transport and electrochemical behaviors of the electrodes made from composites containing carbon nanotubes (CNTs) are discussed, and the challenges that remain in using CNTs and CNT-based composites as well as the prospects for exploiting them in the future are discussed.

418 citations