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Author

Ho-Jun Lee

Bio: Ho-Jun Lee is an academic researcher. The author has contributed to research in topics: Antenna (radio) & Dipole antenna. The author has an hindex of 2, co-authored 5 publications receiving 59 citations.

Papers
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Patent
26 Feb 2001
TL;DR: In this paper, the authors proposed a distributed antenna device for intermediate frequency conversion/process, which comprises a centralized hub unit for transmitting and receiving signals to/from a base transceiver station through a certain antenna, and a coaxial cable connected between the hub unit and the distributed antenna module for transferring signals there.
Abstract: A distributed antenna device for intermediate frequency conversion/process which comprises a distributed antenna module including a plurality of antenna modules packaged therein, each for transmitting and receiving signals to/from a subscriber terminal through a low-power antenna, a hub unit for transmitting and receiving signals to/from a base transceiver station through a certain antenna, and a coaxial cable connected between the hub unit and the distributed antenna module for transferring signals therebetween. According to this invention, the distributed antenna device has the effect of minimizing the number of dead zones and maximizing the entire antenna output capacity with lower power than conventional outdoor switching centers.

49 citations

Proceedings ArticleDOI
05 Jul 2008
TL;DR: In this paper, a compact UWB antenna with band-notch characteristic is proposed, where the spoon-shaped slots are inserted in the pattern of planar monopole antenna to realize the stopband.
Abstract: In this paper, a compact UWB antenna with band-notch characteristic is proposed. To realize the stop-band, the spoon-shaped slots are inserted in the pattern of planar monopole antenna. This antenna is operating in the UWB spectrum from 3.1 to 10.6 GHz and has the stop band from 4.8 GHz to 6.3 GHz where VSWR is higher than 3. This antenna is made by LTCC process and the size of this antenna is 15*15*1 mm3.

6 citations

Journal ArticleDOI
TL;DR: In this paper, the authors proposed a compact ultra-wideband (UWB) antenna with band notch characteristic and the miniaturized antenna is made by low-temperature co-fired ceramic process.
Abstract: In this article, the compact ultra-wideband (UWB) antenna with band notch characteristic and the miniaturized antenna are proposed. To realize the stop band, the spoon-shaped slots are inserted in the pattern of planar monopole antenna. These antennas are operating in the UWB spectrum from 3.1 to 10.6 GHz and has the stop band from 4.8 to 6.3 GHz where VSWR is higher than 3. They are made by low-temperature cofired ceramic process, and the size of the miniaturize antenna is 8 × 15 × 1 mm3. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 717–720, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24190

2 citations

Proceedings ArticleDOI
01 Oct 2008
TL;DR: In this paper, the authors proposed a compact UWB antenna with band-notch characteristic and the miniaturized antenna is made by LTCC process and the size of miniaturize antenna is 8*15*1 mm3.
Abstract: In this paper, the compact UWB antenna with band-notch characteristic and the miniaturized antenna are proposed. To realize the stop-band, the spoon-shaped slots are inserted in the pattern of planar monopole antenna. These antennas are operating in the UWB spectrum from 3.1 to 10.6 GHz and has the stop band from 4.8 GHz to 6.3 GHz where VSWR is higher than 3. They are made by LTCC process and the size of the miniaturize antenna is 8*15*1 mm3.

1 citations

Proceedings ArticleDOI
03 Jul 2005
TL;DR: In this article, a photonic bandgap (PBG) structure was introduced to suppress harmonic radiation from the antenna, and two identical patch antennas operating at 12 GHz were designed to verify the performance of this cell.
Abstract: As a new method to suppress harmonic radiation from the antenna, a 1-dimensional photonic bandgap (PBG) structure is introduced. This cell has a quarter wavelength at cutoff frequency and is inserted in the microstrip line. In order to verify the performance of this cell, two identical patch antennas operating at 12 GHz were designed. Simulation and experimental results show that second harmonics are perfectly removed.

1 citations


Cited by
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Patent
10 Jun 2016
TL;DR: In this article, a host node device having a terminal interface that receives downstream channel signals from a communication network and send upstream channel signals to the communication network is described. But the subject disclosure may include, for example, an access point repeater launching the downstream channels as guided electromagnetic waves on a guided wave communication system and to extract a first subset of the upstream channels signals from the guided wave communications system.
Abstract: Aspects of the subject disclosure may include, for example, a host node device having a terminal interface that receives downstream channel signals from a communication network and send upstream channel signals to the communication network. An access point repeater launches the downstream channel signals as guided electromagnetic waves on a guided wave communication system and to extract a first subset of the upstream channel signals from the guided wave communication system. A radio wirelessly transmits the downstream channel signals to at least one client node device and to wirelessly receive a second subset of the upstream channel signals from the at least one client node device. Other embodiments are disclosed.

279 citations

Patent
10 Jun 2016
TL;DR: In this paper, the authors describe a repeater device having a first coupler to extract downstream channel signals from first guided electromagnetic waves bound to a transmission medium of a guided wave communication system.
Abstract: Aspects of the subject disclosure may include, for example, a repeater device having a first coupler to extract downstream channel signals from first guided electromagnetic waves bound to a transmission medium of a guided wave communication system. An amplifier amplifies the downstream channel signals to generate amplified downstream channel signals. A channel selection filter selects one or more of the amplified downstream channel signals to wirelessly transmit to the at least one client device via an antenna. A second coupler guides the amplified downstream channel signals to the transmission medium of the guided wave communication system to propagate as second guided electromagnetic waves. Other embodiments are disclosed.

278 citations

Patent
08 Jun 2016
TL;DR: In this paper, the subject disclosure may include, for example, receiving, by each of a plurality of receivers, one of the plurality of communication signals, each electromagnetic wave of the electromagnetic waves guided by a different one of a different twin-lead transmission lines.
Abstract: Aspects of the subject disclosure may include, for example, receiving, by each of a plurality of receivers, one of a plurality of electromagnetic waves, each electromagnetic wave of the plurality of electromagnetic waves guided by a different one of a plurality of twin-lead transmission lines, each twin-lead transmission line sharing a wire, and each electromagnetic wave of the plurality of electromagnetic waves including a different one of a plurality of communication signals, and obtaining, by each of the plurality of receivers, one of the plurality of communication signals. Other embodiments are disclosed.

273 citations

Patent
21 Oct 2016
TL;DR: In this paper, a convex dielectric radome has an operating face that radiates or receives microwave signals, and the face is shaped to reduce an accumulation of water on the operating face.
Abstract: Aspects of the subject disclosure may include, for example, a dielectric antenna and a convex dielectric radome having an operating face that radiates or receives microwave signals. The operating face is shaped to reduce an accumulation of water on the operating face.

243 citations

Patent
02 Feb 2010
TL;DR: In this paper, the authors present an indoor distributed antenna system (IDAS) to provide wireless communication services to clients inside a building or other facility, where the communications can be distributed between a head end unit (HEU) that receives carrier signals from one or more service or carrier providers and converts the signals to Radio-over-Fiber (RoF) signals for distribution over optical fibers to end points.
Abstract: Optical fiber-based wireless systems and related components and methods are disclosed. The systems support radio frequency (RF) communications with clients over optical fiber, including Radio-over-Fiber (RoF) communications. The systems may be provided as part of an indoor distributed antenna system (IDAS) to provide wireless communication services to clients inside a building or other facility. The communications can be distributed between a head end unit (HEU) that receives carrier signals from one or more service or carrier providers and converts the signals to RoF signals for distribution over optical fibers to end points, which may be remote antenna units (RAUs). In one embodiment, calibration of communication downlinks and communication uplinks is performed to compensate for signal strength losses in the system.

238 citations