• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.10
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• pp.1060-1070
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• 2003

The frequency selective surface for use in Ka/Ku band parabolic antenna of domestic satellite communications is proposed. The frequency selective surface structure consists of the infinite periodic arrays of the triple square loop slot element with narrow width on the honeycomb structure of multi-layered dielectric. The frequency selective surface is fabricated and measured. The good agreement is obtained between theory and experiment. It is demonstrated that the frequency selective surface passes 14/12 GHz band wave while reflecting 30/20 GHz band wave as required.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.7
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• pp.3201-3206
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• 2012

In this paper, the simplified design methodology for rotation of polarization plane using a square waveguide is proposed. In order to optimize the characteristics of $180^{\circ}$ polarizer operating from 14.3GHz to 14.8GHz in Ku-band, the modified mode matching method and piecewise power tower interpolation are applied to the polarizer design. The optimized results show that the frequency bandwidth in VSWR<2 has covered 500MHz in the Ku-band and phase difference between two orthogonal modes $TE_{10}$and $TE_{01}$ is $180^{\circ}{\pm}1^{\circ}$ in the range of 14.3GHz~14.8GHz. The cross polarization loss has obtained below 40dB and the insertion loss has 0.1dB in the passband. Therefore, the proposed polarizer is suitable for practical Ku-band system requiring the low VSWR and compact size.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.2
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• pp.19-22
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• 2014

In this paper, Ku-band low phase noise oscillator using DSRR structure resonator based on metamaterial was proposed. To improve the phase noise of the oscillator, the proposed resonator consist of a DSRR strcuture based on metamaterial. The proposed resonator have a characteristic of $S_{11}$ is -0.25 dB, and $S_{21}$ in -44.59 dB at 14.67 GHz, respectively. At 14.67 GHz, the proposed Ku-band low phased oscillator achieves a output power of 2.03 dBm, $2^{nd}$ harmonic of -36.04 dBc, and phase noise of -130.63 dBc at the 100 kHz offset, respectively.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.9
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• pp.46-53
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• 2014

In this paper, ku-band RF transceiver system is designed for the unmanned aerial vehicle(UAV) line-of-sight(LOS) datalink. The RF transceiver system is consisted of the transmitting and receiving unit, RF front-end unit, and high power amplification unit. The transmitting and receiving unit has the functions of frequency up/down converting and channel changing. The RF front-end unit has the functions of transmitting and receiving signal duplexing, antenna selection, small signal amplification, and frequency filtering excluding the receiving signal. The high power amplification unit has the functions of ku-band power amplification and transmitting power variation(High/Middle/Low/Mute). The frequency up/down converting of transmitting and receiving unit is designed by using the superheterodyne method. The RF transceiver system is designed to obtain the broadband and high linearity properties for the reliable transmission and reception of high data-rate and high speed data. Also, the channel changing function is designed to use selectively the frequency as the operation environment of UAV.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.4
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• pp.380-386
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• 2014

In this paper, a higher-order mode coupler using coaxial-structure waveguide for Ku-band monopulse satellite tracking is proposed. The proposed higher-order mode coupler is built in a coaxial structure for compactness and weight reduction, making it suitable for mobile tracking systems. The inner circular waveguide of coaxial-structure is used to extract the fundamental mode signal and the high-order mode signal is extracted from the four slots of the outer circular waveguide and then transmitted via given stepped rectangular waveguide structure. The simulated results show that proposed higher-order mode coupler covers 250 MHz(12.75 GHz ~ 13.00 GHz) bandwidth with return loss and insertion loss characteristics. The antenna patterns of fundamental mode and higher-order mode applicable to monopulse tracking are generated successfully. Designed higher-order mode coupler using coaxial waveguide structure for Ku-band is expected to be used for high precision monopulse satellite tracking systems.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.23 no.4
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• pp.65-71
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• 2023

In this paper, the design, fabrication and verification steps of an electronically scanned array antenna(AESA) for a photonics-based Ku-band FMCW radar system is described. The presented system consists of a transmitter and a receiver respectively, which has a same antenna in the transceiver. The designed antenna has 2×8 array configuration and operates at Ku-band. The VSWR(Voltage Standing Wave Ratio) of each 16-radiators and the coupling power between radiators is measured. Also, in order to minimize the radar system damage because of handover power from the transmitter antenna to the receiver antenna when the transmitter works, the isolation between the transmitter antenna and the receiver antenna is optimized by test. As a result, beamwidth, side lobe level and beam steering characteristic are obtained by synthesizing each radiator pattern measurement data after each beam pattern of 16-radiators is measured in the near-field chamber.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.2
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• pp.168-177
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• 2003

The performance sensitivity analysis due to manufacturing/alignment errors is performed for the Ku-band offset parabola antenna of the domestic Communications and Broadcasting Satellite. The performance variations due to reflector random surface error, which inevitably happens during reflector manufacturing, are statistically analyzed using RMS error and correlation interval. The impact on the antenna performance of the fred hem's position and angular errors is investigated, and the sensitive directions are identified. When the target tolerances are applied, the performance degradations are found to be within the loss budget or corresponding performance margins.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.29 no.7
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• pp.500-507
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• 2018

A three-channel radio frequency (RF) monopulse receiver using a data signal with a maximum transmission rate of 274 Mbps was designed. A monopulse receiver using a broadband communication signal was designed to operate in the Ku band, and it consists of a down-conversion module and a signal-processing module. To satisfy the performance of the proposed RF monopulse receiver, a signal-processing function less than the reception sensitivity for each transmission rate according to the adaptive transmission rate is required. To minimize signal reception and mutual frequency interference of various bandwidths, two RF filters were applied. To verify the satisfaction of system requirements, an AWR Corp. simulation tool was used.

• Journal of Satellite, Information and Communications
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• v.10 no.3
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• pp.137-142
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• 2015

This paper analyzed the background and status of studies for WRC-15 agenda item which considers additional frequency allocations to the fixed-satellite service in Ku-band and considered national future countermeasures. Satellite frequency can be acquired through compliance with the Radio Regulations for international registration and it has been recognized as the limited natural resource, and which leads to intensifying the competition among countries for the preoccupancy of it. Under the circumstances, WRC-15 is going to consider additional allocations to the fixed-satellite service in Ku-band and it is necessary to cope with the situation taking into account adequate protection of the existing services and future plan of frequency usage by the fixed-satellite service.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.26 no.11
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• pp.978-984
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• 2015

In this paper, we designed a RF transceiver operating up to 200 km operating range and 45 Mbps data rate. The RF transceiver operates in Ku band and composed of up/down converter, high power amplifier, front-end elements. To satisfy the operating range of RF transceiver, 10W power amplifier was required and realized by using GaN power amplifier. Moreover, to mitigate mutual interference for different bandwidth signals due to the adaptive transmission speed control function, SAW filter bank structure was used. To verify system requirement satisfaction AWR simulation tool was used.