• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.7
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• pp.1374-1379
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• 2003

In this paper, twoㆍstage low noise amplifier(LNA) for 24㎓ is designed and fabricated using NE450284C HJ-FET of NEC CO. In order to get noise figure and input VSWR to be wanted it is considered input VSWR and noise figure simultaneously in matching-circuit designing. The fabricated two-stage low noise mph u has the gai of 16.6㏈, input VSWR of 1.6, and output VSWR under 1.5.

• Journal of Advanced Navigation Technology
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• v.8 no.2
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• pp.176-183
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• 2004

In this paper, two-stage low noise amplifier(LNA) for S-band is designed and implemented using ATF54143 HEMT of HP CO. In order to get noise figure and input VSWR to be wanted, it is considered input VSWR and noise figure simultaneously in matching-circuit designing. The fabricated two-stage low noise amplifier has the gain of 27.8dB, input VSWR and output VSWR under 1.5.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.10a
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• pp.304-308
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• 2003

In this paper, two-stage low noise amplifier(LNA) for 24GHz is designed and fabricated using NE450284C HJ-FET of NEC CO. In order to get noise figure and input VSWR to be wanted, it is considered input VSWR and noise figure simultaneously in matching-circuit designing. The fabricated two-stage low noise amplifier has the gain of 16.6dB, input VSWR of 1.6, and output VSWR under 1.5.

• ETRI Journal
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• v.32 no.4
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• pp.618-621
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• 2010

A low cross-polarization broadband stacked patch antenna is proposed. By means of the stacked patch configuration and probe-fed strip feed technique, the VSWR 1.2:1 bandwidth of the patch antenna is enhanced to 22% from 804 MHz to 1,002 MHz, which outperforms the other available patch antennas (<10%). Furthermore, the antenna has a cross-polarization level of less than -20 dB and a gain level of about 9 dBi across the operating bandwidth. Simulation results are compared with the measurements, and a good agreement is observed.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.11 no.2
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• pp.101-107
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• 1986

Analysis and design procedure for the low noise amplifier design are presented. A Microwave low noise amplifier is designed and fabricated using packaged GaAs FET at the center frequency of 12GHa. The experimental results with respect to the noise figure and power gain are quite agreeable with the design specifications except that the input and output VSWR are slightly higher than the desingned.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.11 no.8
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• pp.1455-1461
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• 2000

There are many researches to increase bandwidth of the microstrip patch antenna for wireless LAN. In spite of broad bandwidth, Bow-Tie antenna has disadvantages that are low gain and big size. In this paper, stacked Bow-Tie microstrip patch antenna for wireless LAN is designed in 5.725 ~5.825 GHz band. This antenna has characteristics that are broadband bandwidth, high gain and small size compared with microstrip patch antenna. In simulated results, the return loss is -34.2 dB at 5.78 GHz and bandwidth is 11.345% for VSWR 2:1 and 7.75%for VSWR 1.5:1. In measured results, the return loss is -38.45 dB at 5.78 GHz and bandwidth is 13% for VSWR 2:1 and 5.6% for VSWR 1.5:1. It has 73.16$^{\circ}$ -3dB beam width and 6.5dB gain.

• Journal of the Microelectronics and Packaging Society
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• v.12 no.2 s.35
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• pp.105-109
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• 2005

A compact antenna switch module for GSM/DCS dual band applications based on multilayer low temperature co-fired ceramic (LTCC) substrate is presented. Its size is $4.5{\times}3.2{\times}0.8 mm^3$ and insertion loss is lower than 1.0 dB at Rx mode and 1.2 dB at Tx mode. To verify the stability of the developed module to the process window, each block that is diplexer, LPF's and bias circuit is measured by probing method in the variation with the thickness of ceramic layer and the correlation between each block is quantified by calculating the VSWR In the mean while, two types of bias circuits -lumped and distributed - are compared. The measurement of each block and the calculation of VSWR give good information on the behavior of full module. The reaction of diplexer to the thickness is similar to those of LPF's and bias circuit, which means good relative matching and low value of VSWR, so total insertion loss is maintained in quite wide range of the thickness of ceramic layer at both band. And lumped type bias circuit has smaller insertion itself and better correspondence with other circuit than distributed stripline structure. Evaluated ceramic module adopting lumped type bias circuit has low insertion loss and wider stability region of thickness over than 6um and this can be suitable for the mass production. Stability characterization by probing method can be applied widely to the development of ceramic modules with embedded passives in them.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.8
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• pp.1352-1358
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• 2006

In this paper, we have fabricated and tested a broad band bow-tie slot antenna with dual reflector. If we put 1/2 length thin and long slot on a wide metal plate, the slot antenna radiates efficient and strong radio wave as same as 1/2 dipole antenna does. we made with bow-tie form slot which has wider broad band than normal rectangular slot. At first, we made and test a single reflector slot antenna. To enlarge the broad band, we inserted another reflection plate between the slot antenna and reflection plate. After the test, we could have known that the low band(VSWR<2.0) has about $22%(793MHz\sim992MHz)$, high band(VSWR<2.0) has about 61% (1626MHz\sim3064MHz).

• Proceedings of the IEEK Conference
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• 2000.11a
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• pp.497-500
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• 2000

There are many researches to increase bandwidth of the microstrip patch antenna for wireless LAN. In spite of broad bandwidth, Bow-Tie microstrip patch antenna, broadband microstrip patch antenna, has disadvantages that are low gain and big size. In this paper, stacked Bow-Tie microstrip patch antenna for wireless LAN is designed in 5.725∼5.825㎓ band. This antenna has characteristics that are broadband bandwidth, high gain and small size compared with microstrip patch antenna. In simulated results, the return loss is -34.2㏈ at 5.78㎓ and bandwidth is 11.345% for VSWR 2：1 and 7.75% for VSWR 1.5：1. In measured results, the return loss is -38.45㏈ at 5.78㎓ and bandwidth is 13% for VSWR 2：1 and 5.6% for VSWR 1.5：1. It has 59.37$^{\circ}$-3㏈ beam width and 6.5㏈ gain.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2000.11a
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• pp.341-344
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• 2000

There are many researches to increase bandwidth of the microstrip patch antenna for wireless LAN. In spite of broad bandwidth, Bow-Tie microstrip patch antenna, broadband microstrip patch antenna, has disadvantages that are low gain and big size. In this paper, stacked Bow-Tie microstrip patch antenna for wireless LAN is designed in 5.725～5.825GHz band. This antenna has characteristics that are broadband bandwidth, high gain and small size compared with microstrip patch antenna. In simulated results, the return loss is -34.2dB at 5.78GHz and bandwidth is 11.345% for VSWR is 2:1 and 7.75% for VSWR is 1.5:1. In measured results, the return loss is -38-45dB at 5.78GHz and bandwidth is 13% for VSWR is 2:1 and 5.6% for VSWR is 1.5:1.