• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.13 no.10
• /
• pp.1089-1097
• /
• 2002

In this paper, the novel shipboard Active Phased Array Antenna(APAA) system for maritime mobile satellite communications is introduced. The antenna uses novel technologies like wide range hybrid tracking, single antenna elements with both of Rx and Tx, asymmetrical array structure, interference isolation between Rx and Tx, and error correction method from frequency scan effect. The antenna has single aperture for both of Rx and Tx with 32 $\times$ 4 two-dimensional array. The antenna has two beams. Its frequencies are 7.25 ~ 7.75 GHz for Rx and 7.9 ~ 8.4 GHz for Tx. The antenna gains are 35.4 dBi for Rx and 35.7 dBi for Tx, those are 54 % of efficiency. The electrically steering ranges are $\pm$35$^{\circ}$ of elevation direction and $\pm$4$^{\circ}$ of azimuth direction. The mechanical control ranges at hybrid tracking capability are continuous 360$^{\circ}$ of azimuth direction and $\pm$10$^{\circ}$ of elevation direction. The antenna has 2.2$^{\circ}$ of 3 dB beamwidth, -14 dB of sidelobe level, and 21 dB of cross-pol suppression. The antenna performance was measured by near field measurement set. Its system performance was tested on the ship motion simulator and with the satellite transponder simulator. The test result showed that its tracking error was within -3 dB from its peak gain under motion condition. The antenna system was tested by real modulated Direct Broadcasting Satellite(DBS) signals to check its communication processing function.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.59 no.11
• /
• pp.1980-1985
• /
• 2010

This paper is about design of optimal structure of slot antenna array antenna with inner waveguide in accordance with the slot model, and fabrication of its prototype sample operating at the frequency of 24 GHz. Results of this work can be employed as a useful tool to develop and diversify slot antenna having superior performance and omni-directivity to that of current antenna. The implemented antenna demonstrates ultra-wideband performance for frequency ranges 24 GHz with the relatively high and flat antenna gain of 18.64dBi and low sidelobe levels. In addition, a $2{\times}8$ antenna array for phased-array systems and mm-wave sensor applications is also presented.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.50 no.7
• /
• pp.59-67
• /
• 2013

The radiation characteristics of an E-plane linear array antenna composed of inductive loaded patch antennas (ILPAs) are investigated. The radiation characteristics of an ILP array antenna are significantly improved compared to those of a conventional array antenna because the mutual coupling of an ILP array antenna is very small. The patch length of a $5{\times}2$ ILPA for the enhancement of the radiation characteristics of a 5-element E-plane linear array antenna composed of ILPAs is presented.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.20 no.10
• /
• pp.1061-1070
• /
• 2009

In this paper, we have designed TDL(True-time Delay Line) for eliminating beam-squint occurring in active phased array antenna with large electrical size operated in wide bandwidth, and have tested its electrical performance. The proposed TDL device is composed of 4-bit microstrip delay line structure and MMIC amplifier for compensation of the delay-line loss. The measured results of gain and phase versus delay state satisfy the electrical requirements, also P1dB output power and noise figure meet the requirement. To verify the performance of fabricated TDL, we have simulated the beam patterns of wide-band active phased array antenna using the measured results and have certified the beam pattern compensation performance. As a result of simulated beam pattern compensation with respect to the 675.8 mm size antenna which is operated in X-band, 800 MHz bandwidth, we have reduced the beam squint error of ${\pm}1^{\circ}$ with ${\pm}0.1^{\circ}$. So this TDL module is able to be applied to active phase array antenna system.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.21 no.3
• /
• pp.763-770
• /
• 1996

In this paper, the Single-stage Transmission type Injectiong-Locked Oscillator(STILO) was designed and fabicated for the Active Integrated Phased Array Antenna(AIPAA) system. The STILO, which was designed and fabricated by injection-locked technique and hair-pin resonator, has the same 210MHz frequency tuning range of the Voltage Controlled Oscillator(VCO) used by varactor. The locking bandwidth of STILO with 11.5MHz bandwidth, is much better than that of the Injection-Locked Dielectric Resonator Oscillator(ILDRO), And the STILO has the improved noise characteristics in AM, FM, and PM. This STILO is useful for the AIPAA, the coupled VCO array, an the MMIC structure.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.22 no.8
• /
• pp.1622-1631
• /
• 1997

A 3-stages Active Microstrip Phased Array Antenn(AMPAA) is implemented using Injection-Locking Coupled Oscillators(ILCO). The AMPAA is a beam scanning active antenna with capability of electrical scanning by frequency varation of ILCO. The synchronization of resonance frequencies in array elements is occured by ILCO, and the ILCO amplifies the injection signal and functions as a phase shifter. The microstrip ptch is operated as a radiation element. The unilateral amplifier is a mutual coupling element of AMPAA, eliminates the reverse locking signal and controls the locking bandwidth of ILCO. The possibility of Monolithic Microwave Integrated Circuits(MMIC) of T/R module is proposed by simplified and integrated fabrication process of AMPAA. The 0.75.$lambda_{0}$ is fixed for a mutual coupling space to wide the scanning angle and minimize the multi-mode. The AMPAA has beam scanning angle of 31.4.deg., HPBW(Half Power Beam Widths) of 26.deg., directive gain of 13.64dB and side lobe of -16.5dB were measured, respectively.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.21 no.5
• /
• pp.913-920
• /
• 2017

In this development, By using the phase array antenna, the beam around was electronically revolved and the marine fixed type radar of which the detection is possible was made and the check around was tested. There are the risk of the corrosion because of the abrasion of the axis of rotation and salinity with the way that the existing marine pulse radar detects the check by using the mechanical rotation. Besides, the maintenance cost of the magnetron gets to happen by using the detection signal. In this development, The fixed type radar of the low output which revolves electronically around the beam by using the radar signal processing method of the phase array antenna using the phase shifter and FMCW(Frequency Modulation Continuous Wave) method was made. And by using the fixed type radar, the check detection test was conducted.

• Proceedings of the Korean Institute of Communication Sciences Conference
• /
• 1998.10a
• /
• pp.788-791
• /
• 1998

• Journal of the Korean Institute of Telematics and Electronics A
• /
• v.30A no.1
• /
• pp.1-7
• /
• 1993

The radiation characteristics of a phased array antenna consisted of rectangular waveguides with a slant grid are investigated here. In particular, the effects of the slant angle on the radiation patterns are calculated by solving numerically the integral equation to the electric field over the waveguide aperture in view of the modal analysis. And it is found that the blindness on the radiation pattern can be moved by inserting a dielectric plug or sheath properly.

• Journal of the Korean Institute of Telematics and Electronics A
• /
• v.29A no.2
• /
• pp.24-32
• /
• 1992

The impedance matching properties of infinite planar arrays of rectangular waveguides with dielectric plug loading and sheath covering are studied here. The effects of several involved parameters on the impedance matching of the phased array antenna are investigated by calculating the reflection coefficients numerically. The improvement of impedance matching and the appearance of forced surface wave resonances are also discussed.