• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.17 no.5
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• pp.351-357
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• 2024

The power handling capacity of the Loran-C transmitting antenna for terrestrial navigation was analyzed in this paper. The power handling capacity of a shortened umbrella-type monopole antenna for terrestrial navigation is determined by the insulation voltages of the base and guy insulators used in the antenna in addition to the effective height of the antenna. In this paper, the insulation voltage of the base insulator according to the transmitting antenna power was derived, and in order to obtain the insulation voltages of the points where the antenna and the guy lines are connected, the antenna voltages for the antenna height were derived. By comparing with the insulation voltages of the insulators used, the power handling capacity of the antenna can be analyzed. As a result of comparative analysis of the insulation characteristics of the insulators used for the transmitter antenna, the guy line insulation voltages were approximately 69[kV]~128[kV] depending on the antenna output of 50[kW]~100[kW], so the method of using two guy insulators in series was appropriate, and the insulation voltages at the base of the antenna were 64.8[kV]~91.7[kV], so it was possible to have a power handling capacity that could operate the antenna output power from 50[kW] to 100[kW].

• ETRI Journal
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• v.33 no.1
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• pp.6-12
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• 2011

A case study of an active transmitting patch antenna revealed a characteristic loop locus of DC power versus RF output power as drive frequency was varied, with an operational bandwidth substantially smaller than the impedance bandwidth of the radiator. An approximate simulation technique, based on separation of the output capacitance of the power transistor, yielded easily visualized plots of power dependence on internal load impedance, and a simple interpretation of the experimental results in terms of a near-resonance condition between the output capacitance and output packaging inductance.

• Proceedings of the KSRS Conference
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• v.1
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• pp.204-207
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• 2006

COMS will receive two different meteorological signals in S-Band from IDACS (Image Data Acquisition and Control System) in ground station before transmitting them in L-Band to user station. MODCS (Meteorological Ocean Data Communication Subsystem) in satellite released the value of required PFD (Power Flux Density) to receive two signals. Thus, DATS (Data Acquisition and Transmission Subsystem) needs to send two signals to satellite with a satisfied EIRP. The value of minimum HPA (High Power Amplifier) output power was estimated by subtracting antenna directional gain and path loss between antenna and HPA from the needed EIRP in this paper. Besides the minimum output power of HPA, the maximum output power was also calculated with considering IMD (Inter-Modulation Distortion) characteristics. IMD is always occurred in the output of HPA when LRIT and HRIT are amplified by using single HPA as COMS application. In this paper, the setting of maximum output power was determined when the IMD of modelled HPA was corresponded to the requirement of MODCS.

• International Journal of Internet, Broadcasting and Communication
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• v.16 no.1
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• pp.330-338
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• 2024

In this paper, a Ka-band high-output active phased array antenna device applicable to small radars and seekers was designed, and the improved performance was studied. The radiation device assembly consists of 1x8 arrangements, and the step flared notch antenna type. It shows low active reflection loss characteristics in broadband, and low loss characteristics by applying the air-strip feeding structure, and is designed to enable beam steering up to 45 degrees. The TRM(transmit receive module) output power is more than 2.0W per channel using GaN HPA in the transmitting path, and satisfies more than 25.0 dB gain and less than 6.0 dB noise figure in the receiving path. Accordingly, the Effective Isotropically Radiated Power(EIRP) of the antenna unit shows the performance of 0.00 dB or more and the receive gain-to-noise temperature ratio(G/T) of 0.00 dB/k or more. For demonstration, we have designed aforementioned planar array antenna which consists of 64 radiating elements having a size within 130 mm x 130 mm x 300 mm and weight of less than 4.9 kg..

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.4
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• pp.1889-1910
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• 2017

This paper investigates a protocol so-called Adaptive Harvest Then Transmit (AHTT) for wireless powered communication networks (WPCNs) in multiple-input single-output (MISO) downlink systems, which assists in transmitting signals from a multi-antenna transmitter to a single-antenna receiver. Particularly, the power constrained relay is supplied with power by utilizing radio frequency (RF) signals from the source. In order to take advantage of multiple antennas, two different linear processing schemes, including Maximum Ratio Combining (MRC) and Selection Combination (SC) are studied. The system outage capacity and ergodic capacity are evaluated for performance analysis. Furthermore, the optimal power allocation is also considered. Our numerical and simulation results prove that the implementation of multiple antennas helps boost the energy harvesting capability. Therefore, this paper puts forward a new way to the energy efficiency (EE) enhancement, which contributes to better system performance.

• ETRI Journal
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• v.31 no.4
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• pp.357-364
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• 2009

In this paper, we propose a novel equalization on-channel repeater (OCR) with a feedback interference canceller (FIC) to relay terrestrial digital multimedia broadcasting signals in single frequency networks. The proposed OCR not only has high output power by cancelling the feedback signals caused by insufficient antenna isolation through the FIC, but also shows better output signal quality than the conventional OCR by removing multipath signals existing between the main transmitter and the OCR through an equalizer. In addition, computer simulations and laboratory test results demonstrate that the proposed OCR successfully cancels feedback signals and compensates channel distortions and provides a higher quality transmitting signal with higher output power than conventional OCRs.

• Journal of the Korea Computer Industry Society
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• v.2 no.9
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• pp.1147-1154
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• 2001

In this paper, we make plans for facilities, the 8-VSB DTV transmission system, installed in the near future, based on presently NTSC TV operating it. First of all we estimate transmission power for analog NTSC, digital 8-VSB terrestrial broadcasting and the effective condition of optimal receiving power result from it. It's also to estimate optimal receiving condition by using Longley-Rice's Field Strength calculating method that is to guess a profile between transmitting station and many receiving points. The 8-VSB DTV Propagation aims to high-speed transmission rates of 19.39Mbps datum to enable HDTV(High Definition Television) at NTSC 6MHz bandwidth. First of all, an optimization of field strength between transmission station and receiver must deal with considerable. Because of these reasons, 8-VSB DTV transmission needs effective extension for NTSC TV service coverage. Finally we present the transmitting output that is expected in changing NTSC VHF to DTV UHF for maintaining the transmitting output of NTSC TV that is equal to 8-VSB DTV in service coverage.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.18 no.6
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• pp.163-168
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• 2018

We developed W-band transceiver module using open MMIC chip such as receiver single chip and transmitting power amplifier. In order to calculate the noise figure and output power value, we analyzed the W-band transition loss from the antenna to MMIC connection and constructed the 12 channel receiver and the 5 channel transmitter. And compared with the results of the measurement. As a result, the output power of the transmitter was similar to the analytical results and the measured results at room temperature and environmental conditions. The noise figure of the receiver was also similar, but some channels showed error of about 3 dB due to manufacturing error.

• Journal of the Korea Institute of Military Science and Technology
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• v.23 no.1
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• pp.59-65
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• 2020

Many technologies are being studied to reduce the RCS(Radar Cross Section) of stealth aircraft. Most RCS-reduction technlogies correspond to platforms. It is important to identify factors that RCS performance through simulation analysis of aircraft Mounted equipment. In particular, there are no studies of RCS performance in the radar frequency band when antenna transmit signals are applied. In this paper, the RCS performance variation on the transmit signal on/off of antennas mounted on a stealth aircraft was verified. Antennas were selected for each frequency band and simulated analysis to the RCS performance changes during antenna transmitting signal. Finally, to verify the characteristics of the change in RCS performance, RCS test measurements on the low-profile antenna transmit signal on/off were performed. In addintion, antenna RCS test measurement was performed according to the change of transmit signal power output. As a result, it was confirmed that there is no change in RCS performance when an antenna transmit signal is applied.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.11C
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• pp.1564-1572
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• 2004

UWB(Ultra Wide Band) under standardization for WPAN has a restriction in transmitting power because of interference with existing systems. To overcome the restriction, in this paper, we construct the MIMO(Multi-input-Multi-Output) channel using multi-transmit/receiver antennas and analyze the performance of the proposed system. In addition, through numerical simulation, we obtain the interference property among these antennas and analyze the effect of an interference to the system. The proposed UWB system has a ML detector and the least square method will be used to cancel the multi-user interference and the inter symbol interference caused by multipath.