• Journal of electromagnetic engineering and science
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• v.15 no.4
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• pp.232-238
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• 2015

This work describes the development of a D-band (110-170 GHz) signal source based on a SiGe BiCMOS technology. This D-band signal source consists of a V-band (50-75 GHz) oscillator, a V-band amplifier, and a D-band frequency doubler. The V-band signal from the oscillator is amplified for power boost, and then the frequency is doubled for D-band signal generation. The V-band oscillator showed an output power of 2.7 dBm at 67.3 GHz. Including a buffer stage, it had a DC power consumption of 145 mW. The peak gain of the V-band amplifier was 10.9 dB, which was achieved at 64.0 GHz and consumed 110 mW of DC power. The active frequency doubler consumed 60 mW for D-band signal generation. The integrated D-band source exhibited a measured output oscillation frequency of 133.2 GHz with an output power of 3.1 dBm and a phase noise of -107.2 dBc/Hz at 10 MHz offset. The chip size is $900{\times}1,890{\mu}m^2$, including RF and DC pads.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.8 s.111
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• pp.767-772
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• 2006

The receiver of this paper is Dual-band monopulse type for prototype of tracking radar. Localization of radar technology is an issue of SamsungThales and go into development. Dual-band radar in comparison with Single-band radar requires higher cost and power consumption but there are many advantages of dealing with jamming, detection range, image signal rejection, cloud-rain influence, clutter, resolution. The receiver is comprised of X-band RF head module, Ka-band RF head module and common IF module. Each signal of X-band and Ka-band is selected by the switch in If module. Phase shifter in IF module of local stage controls the phase of sum, azimuth, elevation channel. In the test result, gain is $40{\pm}3 dB$, isolation of transmitter/receiver is 39 dBc, dynamic range is 110 dB and noise figure of each channel is 4.5dB and 6.9dB.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.5
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• pp.815-820
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• 2008

Recently the frequency assignment and the technical specifications of UWB systems for communications are completed. Therefore many UWB systems have been developed. In our country $3.1{\sim}4.8GHz$ and $7.2{\sim}10.2GHz$ are assigned for UWB systems for communications. When we consider RF technologies and the easy implementation of UWB systems, UWB systems used in the low band are more developed than high band systems. In this paper we design and implement a BPF for low band UWB systems by means of considering the easy implementation of UWB systems. The designed and implemented BPFs are low band filter and low band channel filters. The measured results of the low band filter show that the filter has 21.85dB and 17.91dB attenuation at 3.1GHz and 4.8GHz, 1.53GHz of -10dB bandwidth and 2dB of insertion loss. Low band can be divided into 3 channels with 500MHz of the channel bandwidth. The channel filter for channel number 1 has the characteristics of 24.85dB attenuation at 3.1GHz, 0.61GHz of -10dB bandwidth and 1.87dB of insertion loss. The filter for channel 3 in low band has 19.2dB of attenuation at 4.8GHz, 0.49GHz of -10dB bandwidth and 2.49dB of insertion loss.

• Journal of Satellite, Information and Communications
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• v.8 no.3
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• pp.47-51
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• 2013

In this paper, we present design and test results of a Ka-band dual-band ortho-mode transducer (OMT) for use in a feed assembly for the very small aperture terminals (VSATs). The designed ortho-mode transducer have wideband characteristics to separate the signals that have two orthogonal linear polarizations operating at 20GHz of receive frequency band and at 30GHz of transmit frequency band. In addition, in order to reduce the volume of the feed assebly, a Boifot based ortho-mode transducer has been designed with a dual-band. Experimental results for the design verification, the return loss in the receive band and in the transmit band for the horizontal polarization showed over 20dB and 21dB, respectively, and for the vertical polarization showed over 20dB and 24dB, respectively. The port isolation for the horizontal polarization and the vertical polarization showed over 43dB and 52dB, respectively, in the receive band and in the vertical band.

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.6
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• pp.1053-1058
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• 2021

This paper presents the multi-band mixer which converts a X-, K- and Ka-band adaptively by adjusting the gate-bias voltage of an active device. The proposed mixer presented a conversion loss of -10 dB at -0.8 V gate-bias voltage for X-band, a conversion loss of -9 dB at -0.3 V gate-bias voltage for K-band and for Ka-band, a conversion loss of -7 dB at -0.2 V gate-bias voltage under the LO power of +6.0 dBm. The 1dB compression point (P1dB) is +0.5 dBm for all band.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.3
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• pp.376-379
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• 2014

In this paper, we designed more improving a dual-band power amplifier than the transceiver of RFID reader that operates at 910 MHz and 2.45 GHz. A dual-band power amplifier has two circuits. One matching circuit is composed lumped element in the band of 910 MHz. The other matching circuit using distributed element in the high band of 2.45 GHz. So, this dual-band power amplifier works as Band Rejection Filter in the band of 910 MHz but in the high band of 2.45 GHz works as Band Pass Filter. Therefore, this is composed a microstrip transmission line. A power amplifier is showed gains of 8 dB output power at 910 MHz and 1.5 dB output power at 2.45 GHz. If input power is 10 dBm, both of bands output 20 dBm.

• The Journal of the Korea institute of electronic communication sciences
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• v.11 no.1
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• pp.23-28
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• 2016

In this paper, a Multi-Band Ku-band down converter was designed for reception of multi-band digital satellite broadcasting. The Multi-band low-nose down converter was designed to form four local oscillator frequencies (9.75, 10, 10.75 and 11.3GHz) representing a low phase noise due to VCO-PLL with respect to input signals of 10.7 to 12.75GHz and 3-stage low noise amplifier circuit by broadband noise matching, and to select an one band of intermediate frequency (IF) channels by digital control. The developed low-noise downconverter exhibited the full conversion gain of 64dB, and the noise figure of low-noise amplifier was 0.7dB, the P1dB of output signal 15dBm, and the phase noise -73dBc@100Hz at the band 1 carrier frequency of 9.75GHz. The low noise block downconverter (LNB) for receiving four-band digital satellite broadcasting designed in this paper can be used for satellite broadcasting of vessels navigating international waters.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.31B no.5
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• pp.42-49
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• 1994

In this paper we consider efficient 1-D and 2-D linear-phased half-band filter designs. We first introduce a new derivation of the existing Vaidynathan-Nguyen 's half-band filter design method, which verifies that the design provides optimal half-band filters. We then propose an approximately-linear-phased IIR half-band filter design method, which is based on the all-pass equalizer design with the linear phase -$\omega$/2. Finally, we propose an efficient method to design optimal 2-D half-band filters, for which we utilize a 2-D all pass prototype filter of half the order of the desired 2-D half-band filters.

• ETRI Journal
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• v.23 no.1
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• pp.1-8
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• 2001

The performance of a long wavelength-band erbium-doped fiber amplifier (L-band EDFA) using 1530nm-band pumping has been studied. A 1530nm-band pump source is built using a tunable light source and two C-band EDFAs in cascaded configuration, which is able to deliver a maximum output power of 23dBm. Gain coefficient and noise figure (NF) of the L-band EDFA are measured for pump wavelengths between 1530nm and 1560nm. The gain coefficient with a 1545nm pump is more than twice as large as with a 1480nm pump. It indicates that the L-band EDFA consumes low power. The noise figure of 1530nm pump is 6.36dB at worst, which is 0.75dB higher than that of 1480nm pumped EDFA. The optimum pump wavelength range to obtain high gain and low NF in the 1530nm band appears to be between 1530nm and 1540nm. Gain spectra as a function of a pump wavelength have bandwidth of more than 10nm so that a broadband pump source can be used as 1530nm-band pump. The L-band EDFA is also tested for WDM signals. Flat Gain bandwidth is 32nm from 1571.5 to 1603.5nm within 1dB excursion at input signal of -10dBm/ch. These results demonstrate that 1530nm-band pump can be used as a new efficient pump source for L-band EDFAs.

• Applied Biological Chemistry
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• v.27 no.2
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• pp.129-134
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• 1984

Change of protein component in soybean sprout grown at four temperatures was investigated by polyacrylamide gel electrophoresis. Main bands were identified using purified seed globulins. Electrophoretogram showed 5 main bands (a. b, c, d, and p) and 10 minor bands in seed and maximum number (19) of bands (8 main band including 0 and 11 minor) at 4th day after germination in cotyledon. All bands appeared in axis protein but resolution was poor. In cotyledon, a component (most rapidly) and b+c+d component decreased while o+p component and other minor components were increased at 6th day and decreased thereafter. In axis all components increased rapidly, especially in minor components and b+c+d component. High growing temperature accelerated decrease in cotyledon and increase in axis of protein, especially for 11S. The a component was identified as 7S, b+c+d as 11S and o+p as 2S globulin.