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Woo-Kyung Lee

Bio: Woo-Kyung Lee is an academic researcher from Korea Aerospace University. The author has contributed to research in topics: Synthetic aperture radar & Inverse synthetic aperture radar. The author has an hindex of 6, co-authored 44 publications receiving 169 citations.

Papers
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Journal ArticleDOI
TL;DR: In this article, a novel phased array antennas suitable for X-band satellite communication are introduced and investigated for right-handed circular polarization (RHCP) in a multi-layered fabrication.
Abstract: Novel phased array antennas suitable for X-band satellite communication are introduced and investigated for right-handed circular polarization (RHCP) in a multi-layered fabrication. The primary function of the proposed antennas is to transmit high quality data obtained from satellites and the ground station systems with the lowest amount of loss. For accurate data transmission, the important parameters regarding antenna specifications and electrical performance are the antenna gain and the high-purity polarization. Hence, this paper describes novel procedures for gain enhancements of the array antennas working at X-band (from 8.0 to 8.5 GHz) with an RHCP characteristic, including a single element, 2×2 array, and 2×4 array with four-way and eight-way power dividers, respectively. Taking into consideration the long-distance communication between a satellite and ground station, a substrate-integrated waveguide structure has been proposed, in particular because it is known to have low radiation loss and a low weight comparable to that of a microstrip, as well as low material loss similar to that of a metal-surrounded waveguide.

50 citations

Journal ArticleDOI
TL;DR: In this article, a structural modification of S-band turnstile antenna with cylindrical parasitic elements around a main radiator is introduced and investigated with respect to its gain, axial-ratio (AR) beamwidth, and radiation pattern.
Abstract: A structural modification of S-band turnstile antenna with cylindrical parasitic elements around a main radiator is introduced and investigated with respect to its gain, axial-ratio (AR) beamwidth, and radiation pattern. The overall structure is composed of a main radiator of two crossed bowtie-shaped dipole antennas and a feeding network using a Wilkinson power divider with phase differences between two parts. A final optimization of the parameter values for the enhancement of AR beamwidth is carried out from the parametric studies. The proposed antenna has not only a broad 5-dB AR bandwidth of 12.3% ranging from 2025 to 2290 MHz, but also a stable peak gain of 7.6 dBic with circular polarization (CP) characteristic.

36 citations

Proceedings Article
28 Nov 2011
TL;DR: A design scheme for isoflux pattern antenna suitable for SAR data transmission of LEO satellite requiring wide angle coverage of the earth and constant power transmission to the ground station during the passage on the orbit is presented.
Abstract: In this paper, a design scheme for isoflux pattern antenna suitable for SAR data transmission is presented. An isoflux pattern is suitable for SAR data transmission of LEO satellite requiring wide angle coverage of the earth for the longer time visibility. Also, it is advantageous to provide uniform power density over the earth and constant power transmission to the ground station during the passage on the orbit. Based on the principle of generating isoflux pattern, we design basic isoflux pattern antenna which shows required isoflux characteristics. For improved performance, the basic antenna is optimized with genetic algorithm. The optimized isoflux pattern antenna is designed and implemented and shows rapid skirt characteristics, low side lobe, and low back lobe level.

22 citations

Proceedings ArticleDOI
03 Jul 2011
TL;DR: In this article, a modified triangular-shaped waveguide-typed septum polarizer has been suggested and verified by using commercially available software and carrying out the comparison with the conventional rectangular waveguide -typed polarizer, which showed the better electrical performances than the conventional one in terms of the smooth energy transfer of TE 10 and TE 01 -modes.
Abstract: In this paper, modified triangular-shaped waveguide-typed septum polarizer has been suggested and verified by using commercially available software and carrying out the comparison with the conventional rectangular waveguide-typed polarizer. It is expected that the proposed structure shows the better electrical performances than the conventional one in terms of the smooth energy-transfer of TE 10 and TE 01 -modes. The simulated result shows that the proposed structure accomplished axial ratio of less than 0.32dB, return losses of lower than −32dB, and isolation characteristics between −24dB and −35dB at the target frequency ranging from 8 to 8.4GHz.

15 citations

Journal ArticleDOI
01 Nov 2021-Sensors
TL;DR: In this paper, a compressive sensing-based signal recovery method was proposed for reconstructing synthetic aperture radar (SAR) images by applying a Compressive Sensing (CS) technique to sparsely acquired radar sensor data.
Abstract: In this paper, we propose a method for reconstructing synthetic aperture radar (SAR) images by applying a compressive sensing (CS) technique to sparsely acquired radar sensor data. In general, SAR image reconstruction algorithms require radar sensor data acquired at regular spatial intervals. However, when the speed of the radar-equipped platform is not constant, it is difficult to consistently perform regular data acquisitions. Therefore, we used the CS-based signal recovery method to efficiently reconstruct SAR images even when regular data acquisition was not performed. In the proposed method, we used the l1-norm minimization to overcome the non-uniform data acquisition problem, which replaced the Fourier transform and inverse Fourier transform in the conventional SAR image reconstruction method. In addition, to reduce the phase distortion of the recovered signal, the proposed method was applied to each of the in-phase and quadrature components of the acquired radar sensor data. To evaluate the performance of the proposed method, we conducted experiments using an automotive frequency-modulated continuous wave radar sensor. Then, the quality of the SAR image reconstructed with data acquired at regular intervals was compared with the quality of images reconstructed with data acquired at non-uniform intervals. Using the proposed method, even if only 70% of the regularly acquired radar sensor data was used, a SAR image having a correlation of 0.83 could be reconstructed.

9 citations


Cited by
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Journal ArticleDOI
TL;DR: In this paper, a circularly polarized (CP) antenna based on substrate integrated waveguide (SIW) technology is presented, which is achieved by applying the sequential rotation technique (SRT) with a well-designed sequential feed network and linear-polarized array elements.
Abstract: A circularly polarized (CP) $\text{4}\times\text{4}$ array antenna based on substrate integrated waveguide (SIW) technology is presented. Circular polarization is achieved by applying the sequential rotation technique (SRT) with a well-designed sequential feed network and linear-polarized array elements. The proposed $\text{4}\times\text{4}$ array has a wide axial ratio (AR) bandwidth of 14% from 18.3 to 21.1 GHz with gain $ > \!\!13\,{\rm dBic}$ . Then, the array is expanded to achieve higher gains. A $\text{16}\times\text{16}\hbox{-}{\rm element}$ array is designed, fabricated, and tested. Test results show that the $\text{16}\times\text{16}$ array has an AR bandwidth of 13.8% from 18.5 to 21.25 GHz and a peak gain of 25.9 dBic at 20.5 GHz.

106 citations

Journal ArticleDOI
11 Jan 2021
TL;DR: In this article, the authors present a general overview of substrate integrated transmission lines, from the perspective of historical background and progress of guided-wave structures and their impacts on the development of microwave circuits and integration solutions.
Abstract: This paper presents a general overview of substrate integrated transmission lines, from the perspective of historical background and progress of guided-wave structures and their impacts on the development of microwave circuits and integration solutions. This is highlighted through a technology roadmap involving the categorized five generations of microwave circuits. In particular, the substrate integration technologies are reviewed and discussed with focus on technical features, design highlights, component developments, structures evolution, and systems integration. A number of examples are presented to showcase some of the selected milestone research and development activities and accomplishments in connection with substrate integrated transmission line technologies, with particular focus on substrate integrated waveguide (SIW) techniques. Practical applications and industrial interests are also presented with key references and technical results, which show more and more product developments in the end-user sectors. It can be found that the popularity of SIW techniques is closely related to the achieved seamless integration of planar and non-planar structures into a unified design space, thereby allowing the possibility of combining major advantages of all the structures while alleviating their potential drawbacks. The future perspectives of the substrate integration technology are discussed through five major research directions, which suggest potential impacts in the development of future generations of circuits and systems such as system-on-substrate (SoS).

100 citations

Journal ArticleDOI
TL;DR: In this paper, two single-fed low-profile cavity-backed slot antennas and an antenna array for circular polarization (CP) applications are introduced using the low-cost standard printed circuit board process.
Abstract: Two single fed low-profile cavity-backed slot antennas and an antenna array for circular polarization (CP) applications are introduced. By employing the substrate-integrated waveguide (SIW) and half-mode SIW (HMSIW) techniques in antenna designs, low-profile cavity-backed structures are realized using the low-cost standard printed circuit board process. First, a novel spoon-shaped slot antenna is proposed to realize CP radiation based on the SIW cavity. Then, to minimize the antenna size and achieve the impedance bandwidth enhancement, the HMSIW cavity is introduced to realize a cavity-backed semicircle slot antenna (SSA). The equivalence between the edge of the HMSIW cavity and the longitude slot curved on the surface of the SIW cavity is proposed to guide the design process of the SSA. In addition, two hybrid modes are used to improve the impedance bandwidth of the SSA. Furthermore, a sequential rotation antenna array is introduced to validate the feasibility of the SSA for antenna array application. Finally, the proposed antennas and the antenna array are designed and fabricated at 28 GHz. The measured and simulated results agree very well.

89 citations

Journal ArticleDOI
TL;DR: In this paper, a new main-beam deceptive jamming suppression approach is proposed, using nonhomogeneous sample detection in the frequency diverse array-multiple-input and multiple-output radar with non-perfectly orthogonal waveforms to obtain the jamming-plus-noise covariance matrix with high accuracy.
Abstract: Suppressing the main-beam deceptive jamming in traditional radar systems is challenging. Furthermore, the observations corrupted by false targets generated by smart deceptive jammers, which are not independent and identically distributed because of the pseudo-random time delay. This in turn complicates the task of jamming suppression. In this paper, a new main-beam deceptive jamming suppression approach is proposed, using nonhomogeneous sample detection in the frequency diverse array-multiple-input and multiple-output radar with non-perfectly orthogonal waveforms. First, according to the time delay or range difference, the true and false targets are discriminated in the joint transmit–receive spatial frequency domain. Subsequently, due to the range mismatch, the false targets are suppressed through a transmit–receive 2-D matched filter. In particular, in order to obtain the jamming-plus-noise covariance matrix with high accuracy, a nonhomogeneous sample detection method is developed. Simulation results are provided to demonstrate the detection performance of the proposed approach.

73 citations

Journal ArticleDOI
Qi Wu1, Jiexi Yin1, Chen Yu1, Haiming Wang1, Wei Hong1 
TL;DR: In this article, a single-fed low-profile millimeter-wave substrate-integrated waveguide (SIW) cavity-backed slot antenna for dual-band circular polarization (CP) applications is proposed, which employs two annular exponential slots carved on the surface of a circular SIW cavity.
Abstract: A single-fed low-profile millimeter-wave substrate-integrated waveguide (SIW) cavity-backed slot antenna for dual-band circular polarization (CP) applications is proposed. First, by employing two annular exponential slots carved on the surface of a circular SIW cavity, dual-band CP radiation is achieved. Two different modes, that is, the cavity mode and the surface mode, separately modulated by the cavity field distribution and the surface current, are investigated. They are utilized to achieve the dual-band CP radiation. Next, a two-order matching circuit using inductor windows is introduced to achieve dual-band matching at the low-profile antenna design with the help of the differential evolution method. Finally, for the dual-band CP application at 37.5 and 47.8 GHz, an antenna prototype is fabricated and its performance is evaluated. Simulation and measurement results agree very well.

59 citations