• Journal of Satellite, Information and Communications
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• v.2 no.2
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• pp.64-68
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• 2007

This paper describes the development of RF front.end equipment of a wide band high precision satellite navigation receiver to be able to receive the currently available GPS navigation signal and the GALILEO navigation signal to be developed in Europe in the near future. The wide band satellite navigation receiver with high precision performance is composed of L - band antenna, RF/IF converters for multi - band navigation signals, and high performance baseband processor. The L - band satellite navigation antenna is able to be received the signals in the range from 1.1 GHz to 1.6 GHz and from the navigation satellite positioned near the horizon. The navigation signal of GALILEO navigation satellite consists of L1, E5, and E6 band with signal bandwidth more than 20 MHz which is wider than GPS signal. Due to the wide band navigation signal, the IF frequency and signal processing speed should be increased. The RF/IF converter has been designed with the single stage downconversion structure, and the IF frequency of 140 MHz has been derived from considering the maximum signal bandwidth and the sampling frequency of 112 MHz to be used in ADC circuit. The final output of RF/IF converter is a digital IF signal which is generated from signal processing of the AD converter from the IF signal. The developed RF front - end has the C/N0 performance over 40dB - Hz for the - 130dBm input signal power and includes the automatic gain control circuits to provide the dynamic range over 40dB.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.8 no.6
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• pp.600-613
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• 1997

The implementation of a BTS(Base station Transceiver) for WLL system using W-CDMA(Wideband-Code Division Multiple Access) method is presented in this paper. It consists of three boards; receiver, transmitter and RF controller. Some RF parameters are considered and simulated by the RF simulation S/W using commercial and customized components specifications. The implemented transceiver of 5 MHz RF channel bandwidth satisfies the system requirements of a transceiver such as dynamic range, sensitivity in the receiver and spurious emission suppression in the transmitter. At the receiver, the experimental measurement showed 2.86 dB of NF and 60 dB above of dynamic range in AGC(Automatic Gain Control) locking. At the transmitter, the -49.46 dBc of spurious emission suppression is attained when the output power of the transmitter is 34.3 dBm. These results are good enough to meet to standard performance specifications.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.2
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• pp.287-293
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• 2009

This paper would suggest about data communicate using RF Transmitter-Receiver and about PC protection method authenticate using software of PC which Receiver is connected. Older PC protection system is demanded manual operation of the user but the suggesting method protect PC automatically with judge existing of the user who has Tag approaches the distance which gets near. And it is impossible about the forgery and it is safe about sniffing attack and spoofing.

• ETRI Journal
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• v.26 no.6
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• pp.605-614
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• 2004

In this paper, we investigate array calibration algorithms to derive a further improved version for correcting antenna array errors and RF transceiver errors in CDMA smart antenna systems. The structure of a multi-channel RF transceiver with a digital calibration apparatus and its calibration techniques are presented, where we propose a new RF receiver calibration scheme to minimize interference of the calibration signal on the user signals. The calibration signal is injected into a multi-channel receiver through a calibration signal injector whose array response vector is controlled in order to have a low correlation with the antenna response vector of the receive signals. We suggest a model-based antenna array calibration to remove the antenna array errors including mutual coupling errors or to predict the element patterns from the array manifold measured at a small number of angles. Computer simulations and experiment results are shown to verify the calibration algorithms.

• Proceedings of the KIEE Conference
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• 2002.11c
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• pp.613-616
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• 2002

This paper has been studied an improvement of receive sensitivity for RF module of Industrial Scientific Medical(ISM) Band. In the paper, Also this paper handles receive sensitivity progress of RF module in ISM band. how to improve receive sensitivity adds to Surface Acoustic Wave(SAW) filter, Low Noise Filter(LNA), etc and insulates receiver and transmitter. And then the circuit is inspected by the effective range test of receiver and transmitter. And this Paper was designed that micro-controler controls the part of RF by software.

• JSTS:Journal of Semiconductor Technology and Science
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• v.11 no.1
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• pp.59-64
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• 2011

A low noise and low power RF front-end for 5.8 GHz DSRC (Dedicated Short Range Communication) receiver is presented. The RF front-end is composed of a single-to-differential two-stage LNA and a Gilbert down-conversion mixer. In order to remove an external balun and 5.8 GHz LC load tuning circuit, a single-to-differential LNA with capacitive cross coupled pair is proposed. The RF front-end is fabricated in a 0.13 ${\mu}m$ CMOS process and draws 7.3 mA from a 1.2 V supply voltage. It shows a voltage gain of 40 dB and a noise figure (NF) lower than 4.5 dB over the entire DSRC band.

• Journal of the Semiconductor & Display Technology
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• v.16 no.2
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• pp.85-88
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• 2017

In this paper, we have designed and fabricated a RF-DC voltage multiplier for 5.8GHz microwave wireless power transmission. In order to obtain higher voltage, the RF-DC voltage multiplier with 10 diodes (D-10) and the receiver module with an antenna and BPF (Band Pass Filter) was manufactured. The measured and compared results show that the voltages of the proposed one are lower than those of the previous tripler module up to 40cm. However, the voltage of the proposed one with the voltage multiplier is higher than that of the tripler module at the distances of 45cm and 50cm due to the voltage multiplier with 10 diodes.

• Journal of Satellite, Information and Communications
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• v.5 no.1
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• pp.58-62
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• 2010

This paper presents the effects of RF performance parameters on the Galileo receiver design via simulation after reviewing the requirements of the Galileo receiver structure. At first, we considered the general requirements, structure and characteristics of the Galileo system. Then we designed the Galileo receiver focused on performance requirement of 16 dB C/N which is equal to 15 % Error Vector Magnitude(EVM) by using Advanced Design System(ADS) simulation program. In order to verify the function of Automatic Gain Control(AGC)), we measured the IF output power level by changing the input power level at the front - end of the receiver. We analyzed the performance degradation due to phase noise variations of Local Oscillator(LO) in the Galileo receiver through EVM when the minimum sensitivity level of -127 dBm is applied at the receiver. We also analyzed the performance degradation according to variable Analog-to-Digital Converter(ADC) bits within the Dynamic range, -92 ~ -139 dBm, which has been defined by gain range (-2.5 ~ +42.5 dB) in the AGC operation. The results clearly show that the performance of the Galileo receiver can be improved by increasing ADC bits and reducing Phase Noise of LO.

• The Journal of the Korea institute of electronic communication sciences
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• v.10 no.6
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• pp.665-670
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• 2015

In this paper, We proposed a broadband RF amplifier for Microwave band receiver. We also proposed a broadband RF amplifier, designed by using EM simulation for reliable amplification of the received signal. Connected to a source terminal to via, it minimizes those which are the active elements of source-side oscillation as the operating element in an ideal GND, and a constant gain characteristic in a broadband. The goal of this was to obtain stable amplification characteristics. For implementing this architecture, we designed the broadband(500 MHz ~ 7 GHz) RF amplifier by using commercial GaAs FET, which operate on 720 MHz, 4,595 MHz, and 6,035 MHz by impedance matching. The voltage gain is 10.635 dB ~ 14.407 dB(737.5 MHz ~ 6.0575 GHz), P1dB is 20 dBc of band(1st harmonic/2nd harmonic).

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.47 no.5
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• pp.388-396
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• 2019

This paper describes the RF(Radio Frequency) interference on the GNSS receiver due to the S-band signals transmitted from the transmitters in the Test Launch Vehicle, and analyzes the cause of the RF interference. Due to the S-band signals that have relatively high power levels compared with GNSS signals, an LNA(Low Noise Amplifier) in the active GNSS antenna was saturated, and the intermodulation signal within GNSS in-bands was produced in the LNA whenever two S-band signals were received from the GNSS antenna. For these reasons, the C/N0 of the satellite signals in the GNSS receiver was attenuated severely. The design of the LNA was changed in order to protect the RF interference due to the S-band signals and the suppression capability of the RF interference was confirmed in the new LNA through the comparison of the old LNA.