• Journal of the Korean Institute of Telematics and Electronics
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• v.17 no.4
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• pp.11-17
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• 1980

This paper describes realization of digital filter using $\mu$p controler and discusses measured characteristics of this filter, The idea of P. L. implementation[1] is used in realization, and in this system we utilize a DMA and arithmatic control program of $\mu$p. In this way, we can get more flexible capability than the basic PL method, and higher speed than a filter using general purpose $\mu$p in hardware, Furthermore, we get a 15 KHz sampling frequency(fs) as speed limit in real time processing, and know that this limitation is restricted by execution time (58$\mu$ sec) of DMA control statement. As for filter charateristics, maximum stop band frequencies (fsp) are 1665 Hz, 1445 Hz in Butterworth and Tchebichef approximation, respectively, when fs = 14 KHz. Measured errors between the design specification and the actual result are 0.2dB, 0.1 dB in pass band (when cufoff frequency is 500Hz),-1.1dB (when fsp is 1000Hz), 0.4dB(when fsp is 750 Hz) in stop band frequency of Butterworth and Tchebichef, respectively.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.2
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• pp.303-312
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• 2009

In this paper, we design and fabricate a disk sector antenna fed by CPW fur UWB communications. Also, we insert a rectangular slit on the arc-edge of the disk sector antenna. Then, the antenna has the directivity of E-면. In order to design the antenna, the input impedance is matched with the feed line of $50{\Omega}$ as varying the physical antenna parameters, which are the radius, the flare angle of disk sector, the length of ground, and the length of ground comer near by feed tine. Dimension of the antenna designed for UWB communication is $72mm{\times}26mm$ and bandwidth through computer simulation is $3{\sim}13GHz$. From the measured results, the bandwidth is $1.98{\sim}11GHz$. Return loss and gain of the fabricated antenna are -50.38dB, 1.34dBi at 3.5GHz, -12.27dB, 3.35dBi at 5.5GHz, -23.2dB, 3.8dBi at 8GHz and -16.17dB, 5.2dBi at 10GHz, respectively.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.2
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• pp.491-495
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• 2016

Background: Small B-cell non-Hodgkins lymphoma (NHL) is difficult to be distinguished from non-neoplastic reactive processes using conventional haematoxylin-eosin (HE) staining due to different interpretations among pathologists with diagnosis based on morphologic features. Ancillary examinations such as immunohistochemical (IHC) staining are essential. However, negative or doubtful results are still sometimes obtained due to unsatisfactory tissue processing or IHC technique. The polymerase chain reaction (PCR) as a molecular diagnostic technique is very sensitive and specific. Clonality detection of heavy chain immunoglobulin (IgH) gene rearrangement has been widely used to establish diagnosis of B-cell NHL. Aims: To elaborate interobserver variation in small B-cell NHL diagnosis based on morphologic features only and to confirm sensitivity and specificity of the PCR technique as an ancillary method. Materials and Methods: A toptal of 28 samples of small B cell NHL and suspicious lymphoma were interpreted by 3 pathologists in Sardjito General Hospital based on their morphology only. The reliability of assessment and the coefficient of interobserver agreement were calculated by Fleiss kappa statistics. Interpretation results were confirmed with IHC staining (CD20, CD3, Bcl2). PCR was performed to analyze the clonality of IgH gene rearrangement. Results: Interobserver agreement in morphologic evalution of small B cell NHL and chronic lymphadenitis revealed kappa coefficient 0.69 included in the substantial agreement category. The cases were divided into 3 groups based on morphology and IHC results; lymphoma, reactive process and undetermined group. PCR analysis showed 90% sensitivity and 60% specificity. Conclusions: The present study revealed a substantial agreement among pathologists in small B-cell NHL diagnosis. For difficult cases, PCR is useful as complementary method to morphologic and IHC examinations to establish definitive diagnosis.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2000.10a
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• pp.190-195
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• 2000

This paper presents the fabrication of the LNA which is operating at 2.13∼2.16 GHz for IMT-2000 lot-end receiver using series feedback and resistive decoupling circuit. Series feedback added to the source lead of a transistor keep the low noise characteristics and drop the input reflection coefficient of amplifier simultaneously. Also, it increases the stability of the LNA. Resistive decoupling circuit is suitable for input stage matching because a signal at low frequency is dissipated by a resistor in the matching network The amplifier consist of GaAs FET ATF-10136 for low noise stage and VNA-25 which is internally matched MMIC for high gain stage. The amplifier is fabricated with both the RF circuits and self bias circuit on the Teflon substrate with 3.5 permittivity. The measured results of the LNA which is fabricated using above design technique are presented more than 30 dB in gain P$\_$ldB/ 17 dB and less than 0.7 dB in noise figure, 1.5 in input$.$output SWR(Standing Wave Ratio).

• Journal of IKEEE
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• v.12 no.2
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• pp.95-101
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• 2008

In this paper, we study an optimum design of search synchronization structure for Baseband Modem to support ISO/IEC 18185-5 and 24730-2 Standard. For DSSS Modem, we design the code acquisition and tracking structure which are important in receiver operation, and examine the parameters to be considered. The data and PN chip transmission rates and processing gain of the proposed modem are 59.7 kbps, 30.521875 Mcps, and 27 dB, respectively. This indicates that the noise immunity of the proposed modem is 17dB better than IEEE 802.11b (Processing gain : 10dB). Therefore, we design the optimum structure for the modem search synchronization which is compatible to the proposed modem standard.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.20 no.9
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• pp.900-905
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• 2009

A common drain feedback CMOS wideband LNA with current bleeding and input inductive series-peaking techniques is presented in this paper. DC coupling is adopted between cascode and feedback amplifiers, so that the gain and NF of the LNA can be dynamically controlled by adjusting the bleeding current. The fabricated LNA shows the bandwidth of 2.5 GHz. The high gain mode shows 17.5 dB gain with $1.7{\sim}2.8\;dB$ NF and consumes 27 mW power and the low gain mode has 14 dB gain with $2.7{\sim}4.0\;dB$ NF and dissipates 1.8 mW from 1.8 V supply.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.42 no.3 s.333
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• pp.33-38
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• 2005

In this paper, we have designed and fabricated a hybrid ring coupler to prove the fabrication possibility of various passive components, applying millimeter wave using newly proposed transmission lines, i.e. BAMLs. The characteristics of the fabricated hybrid ing coupler were a the S31(coupling) of 3.58 dB, the S21(thru) of 3.31 dB at the 60 GHz center frequency, the S11(return loss) over 16.17 dB, S41(isolation) over 55 dB at 61 GHz, and the phase difference between port 2 and port 3 of $180{\pm}loat$ 60GHz. In order to reduce the size of hybrid ring coupler, we designed the hybrid ring coupler which inserts a slow wave structure. With this structure, we were able to reduce the hybrid ring coupler by $33\%$ area.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2000.11a
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• pp.61-64
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• 2000

We fabricated and characterized Low Noise Amplifier (LNA) using MCM-C (Multi-Chip-Module-Cofired) technology for 2.14 GHz IMT-2000 mobile terminal application. First, We designed LNA circuits and simulated it's high frequency characteristics using circuits simulator. For the simulation, we adopted high frequency libraries of all the devices used in LNA samples. By the simulation, Gain was 17 dB and Noise Figure was 1.4 dB. We used multilayer process of LTCC (Low Temperature Co-fired Ceramics) substrate and conductor, resistor pattern for the MCM-C LNA fabrication. We made 2 buried inductors, 2 buried capacitors and 3 buried resistors. The number of the total layers was 6. On the top layer, we patterned microstrip line and pads for the SMT device. We measured the high frequency characteristics, and the results were 14.7 dB Gain and 1.5 dB Noise Figure.

• Journal of the Microelectronics and Packaging Society
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• v.12 no.4 s.37
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• pp.323-330
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• 2005

We fabricate PIN PD (Positive Intrinsic Negative Photo-Diode) for CWDM optical repeater and optical transmission system, and analyze theoretically the characteristics to verify the capability of device fabricated. Furthermore, we integrate CWDM filter into PD package to enhance the cost and the performance when compared to the conventional system, in which CWDM filter and PD package are linked by optical fusion splicing. The integrated CWDM PD is fabricated by three steps as follows: CWDM filter design, PD packaging, and product assembly and test. The results of measurement for PD fabricated reveal 0.5 dB bandwidth of 17 nm, isolation over 60 dB at transmission port and over 20 dB at reflection port. Also, the IMD3 for wireless communication is over 63 dBc, and the responsivity of PD presents over 0.9 A/W for 20 samples of the total 23 PD. The total insertion loss reduces about 0.4${\~}$0.7 dB due to the integrated assembly of CWDM and PD.

• Journal of Advanced Navigation Technology
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• v.18 no.4
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• pp.359-363
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• 2014

This paper presents the design and performance of an unequal divider with physical separation and electrical isolation. This divider has a series $18{\Omega}$ resistor and 0.7 pF capacitor circuit between two quarter-wave transmission lines at half phase angle from input terminal. This design method was improved a physical isolation between output ports and easy connected other circuit because of unnecessary of extra transmission line. To show the validity of the unequal divider with complex isolation components, a 4:1 ratio unequal divider was designed and measured at center frequency of 2 GHz. The measured divider performances have the return loss of 17 dB, insertion loss of 1.5 dB and 7.7 dB, and isolation of 18 dB. Its performance is in good agreement with the simulated results.