• Journal of electromagnetic engineering and science
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• v.6 no.1
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• pp.30-35
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• 2006

This paper describes fully integrated low phase noise MMIC voltage controlled oscillators(VCOs). The Asymmetrical Inductance Tank VCO(AIT-VCO), which optimize the shortcoming of the previous tank's inductance optimization approach, has lower phase noise performance due to achieving higher equivalent parallel resistance and Q value of the tank. This VCO features an output power signal in the range of - 11.53 dBm and a tuning range of 261 MHz or 15.2 % of its operating frequency. This VCO exhibits a phase noise of - 117.3 dBc/Hz at a frequency offset of 100 kHz from carrier. A phase noise reduction of 15 dB was achieved relative to only one spiral inductor. The AIT-VCO achieved low very low figure of merit of -184.6 dBc/Hz. The die area, including buffers and bond pads, is $0.9{\times}0.9mm^2$.

• Journal of Crop Science and Biotechnology
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• v.11 no.3
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• pp.163-170
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• 2008

The detection, characterization and use of quantitative traits loci, QTL, have significant potential to improve the efficiency of selective breeding of species. Therefore, a population with 59 advanced backcross lines($BC_2F_5$), derived from a cross between IR64 and Tarome molaei, were studied in Tonekabon Rice Research Station of Iran in order to map QTLs for panicle length, number of grain per panicle, and panicle grain sterility in rice. The parental screening wtih 235 SSR markers in agarose and polyacrylamide gels revealed 114 markers with clear polymorphic bands. To search for QTLs associated with panicle length, number of grain per panicle, and panicle grain sterility, we constructed a genetic linkage map using 114 microsatellite markers. Positive and negative transgressive segregations were observed in $BC_2F_5$ lines for all traits. Using multiple interval mapping(MIM), a total of 20 putative QTLs were detected, of which eight were for panicle length, three for number of grains, and nine for panicle grain sterility. The maximum number of QTLs were mapped on chromosomes 1 and 2 with eight QTLs. These QTL markers could possible be utilized for marker-assisted selection.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.27 no.2
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• pp.115-122
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• 2016

In this paper, wideband Ku-band downconverter was designed to receiver digital satellite broadcasting. The low-nose downconverter was designed to form four local oscillator frequencies(9.75, 10, 10.75 and 11.3 GHz) representing a low phase noise due to VCO-PLL with respect to input signals of 10.7 to 12.75 GHz and 3-stage low noise amplifier circuit by broadband noise matching, and to select intermediate frequency bands by digital control. The developed low-noise downconverter exhibited the full conversion gain of 64 dB, and the noise figure of low-noise amplifier was 0.7 dB, the P1dB of output signal 15 dBm, and the phase noise -85 dBc@10kHz at the band 1 carrier frequency of 9.75 GHz. The low noise block downconverter(LNB) for wideband digital satellite broadcasting designed in this paper can be used for global satellite broadcasting LNB.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.5
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• pp.2443-2448
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• 2013

In this paper, a design of size-reduced microwave oscillator using common defected ground structure (common DGS) is described. At first, an oscillator is designed using the normal stub resonator, and the conventional DGS patterns are inserted for the first trial of size-reduction. Finally, the DGS resonator section is folded by half size in order to adopt the common DGS, and this produces the proposed size-reduced oscillator. Common DGS pattern is inserted for a better size-reduction than when conventional DGSs are used. The folded transmission line is connected using the 3-dimensional signal via-holes. For an example of design, a 2.1GHz oscillator is designed and fabricated using a small signal transistor and common DGS, which shows the size-reduction of 11 mm. The measurement shows 6.7dBm of output power and -133dBc/Hz@1MHz of phase noise. The measured performances are so similar to those of the oscillators before size-reduction and prove the proposed size-reduction method of oscillators using common DGS.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.2 s.105
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• pp.134-138
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• 2006

The isolation performance of the S-band single-pole single-throw(SPST) monolithic microwave integrated circuit (MMIC) switch with two different RF-interconnection approaches, microstrip and grounded coplanar waveguide(GCPW) lines, are investigated. On-to-off isolation is improved by 5.8 dB with the GCPW design compared with the microstrip design and additional improvement of 6.9 dB is obtained with the coplanar wire-bond interconnection(CWBI) at a 3.4 GHz. The measured insertion loss and third-order inter-modulation distortion(IMD3) are less than 1.94 dB over $3.2{\sim}3.6\;GHz$ and greater than 64 dBc.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.46 no.9
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• pp.74-80
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• 2009

This paper describes a $2{\sim}6GHz$ CMOS frequency synthesizer that employs only one LC-tank voltage controlled oscillator (VCO). For wide-band operation, optimized LO signal generator is used. The LC-tank VCO oscillating in $6{\sim}8GHz$ provides the required LO frequency by dividing and mixing the VCO output clocks appropriately. The frequency synthesizer is based on a fractional-N phase locked loop (PLL) employing third-order 1-1-1 MASH type sigma-delta modulator. Implemented in a $0.18{\mu}m$ CMOS technology, the frequency synthesizer occupies the area of $0.92mm^2$ with of-chip loop filter and consumes 36mW from a 1.8V supply. The PLL is completed in less than $8{\mu}s$. The phase noise is -110dBC/Hz at 1MHz offset from the carrier.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.3
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• pp.305-308
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• 2006

A genetic study was conducted to elucidate the effect of alpha-Lactalbumin (${\alpha}$-LA) gene polymorphism on milk production traits involving total milk yield and daily milk yield during first lactation in two breeds of water buffaloes namely, Murrah and Bhadawari. Single strand conformation polymorphism (SSCP) was carried out to explore genetic polymorphism present at this locus. For this study, exon 1 region of ${\alpha}$-LA was analyzed. Finally, polymorphism data was associated with milk production traits by employing least square analysis. In Murrah buffalo, five genotypes such as AB, BB, BC, CC and CD and four alleles A, B, C and D were detected whereas in Bhadawari buffalo two genotypes namely, AB and BC and three alleles namely, A, B and C were found. Genotypes showed significant effects ($p{\leq}0.05$) on total milk yield and daily milk yield in Bhadawari buffalo but had non-significant effects on these traits in Murrah buffalo.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.37 no.8
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• pp.33-44
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• 2000

The lightning with high voltage and current can enter the basestations for mobile communication through their antenna. The device which can protect the basestation against the lightning, is surge arrestor. In this paper, the concept, kind, operating mechanism, design and fabrication of surge arrestor were studied. Based on the studied data, variable surge arrestors were designed for the current mobile communication service like a cellular, GSM and PCS and the next generation mobile communication like a IMT-2000. Computer simulation for the prediction of their characteristics and inner structure optimization for the improvement of their electrical characteristics were carried with high frequency 3D structure simulator. Quarter wave short stub surge arrestors for IMT-2000 were fabricated with their final design and then the measurement of electrical characteristics and the lightning test were executed. As a results of measurement, we obtained below 1.05 of VSWR, -0.035 dB of insertion loss, -150 dBc of intermodulation and 7∼ll V of residual voltage.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.1
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• pp.68-74
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• 2003

This paper describes the design and the test results of the receiver-downconverter module for a Ka-band Satellite Payload. The developed module is not only a downconverter that convert the signal of 30.6 GHz∼31.0 GHz to the signal of 20.8 GHz∼21.2 GHz but also is a receiver that has the function of low noise amplification in the front stage. It has been fabricated and tested by the qualified satellite component manufacturing process and it shows the best performance of the receiver-downconverter modules operating at Ka-band frequency up to date. The module has the performance of 1.9 dB-NF, 55 dB-Gain, and 58 dBc-C/I3 fur the two tone signals of -59 dBm input power respectively at ambient temperature. It is a small and light module with the size of 93 mm${\times}$84 mm${\times}$26 mm and the weight of 240 g.

• Journal of IKEEE
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• v.24 no.1
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• pp.81-89
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• 2020

This paper describes the design and fabrication of a LNB(Low Noise Block downd-converter) which is a component of a FST(Flyaway Satellite Terminal), one of the ET(Earth Terminal) of the military satellite. LNB is physically composed of an down-converter module, a low noise amplifier module, a transmit band suppression filter, a isolator, a housing, and a cable assembly. It was designed using simulator (AWR) to satisfy the electrical characteristics of LNB's such as gain, noise figure and unwanted signal. The gain and noise figure characteristics were measured at 61.4dBm and 1.37dB, respectively. The unwanted wave was measured at -66.79dBc. Of the electrical requirements of Table 1, not only the above three but also all other items were confirmed to be satisfied.