• JSTS:Journal of Semiconductor Technology and Science
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• v.14 no.6
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• pp.712-717
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• 2014

The performance of npn SiGe HBT on thin film SOI is investigated at 32 nm technology node by applying body bias. An n-well is created underneath thin BOX to isolate the body biased SOI HBT from SOI CMOS. The results show that the HBT voltage gain and power gain can be programmed by applying body bias to the n-well. This HBT can be used in variable gain amplifiers that are widely used in the receiver chain of RF systems. The HBT is compatible with 32 nm FDSOI technology having 10 nm film thickness and 30 nm BOX thickness. As the breakdown voltage increases by applying the body bias, the SOI HBT with 3 V $V_{CE}$ has very high $f_tBV_{CEO}$ product (839 GHzV). The self heating performance of the proposed SOI HBT is studied. The high voltage gain and power gain (60 dB) of this HBT will be useful in designing analog/RF systems which cannot be achieved using 32 nm SOI CMOS (usually voltage gain is in the range of 10-20 dB).

• The Journal of Korean Institute of Communications and Information Sciences
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• v.17 no.5
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• pp.509-520
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• 1992

AIGaAs /GaAs HBT OR /NOR gate. which can be used for high speed digital system was designed. Equivalent circuit parameters of HBT were obtained from Gummel-Poon's model and direct extraction method. Simulation results with PSPI CE showed that propagation delay time and cutoff toggle frequency of designed gate were 25ps and 200Hz, respectively. the designed gate exhibited superior properties to the recently reported HBT ECL and MESFET SCFL when considering the fan-out characteristics and noise margin.

• Herbal Formula Science
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• v.17 no.2
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• pp.73-83
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• 2009

Objective : In vitro proapoptotic effect of Hangbaek-Tang (HBT) has been documented by one of us. In the present study, we aimed to demonstrate in vivo effect of HBT on tumor growth. Methods : In vitro selective cytotoxicity of HBT was examined by enumeration of viable cell numbers using BC3A mouse leukemic cells and normal spleen cells. In vivo effect of HBT (25 and 50 mg/mouse) on tumor growth was assayed using BC3A cells innoculated subcutaneously in the flank. Annexin-V apoptosis assay and PI staining was performed to determine the effective serum factor in HBT-treated mice. Leukocyte recruitment into peritoneum were analyzed by microscopy with a stained cytosmear of peritoneal lavage fluid. Results : HBT exhibited in vitro selective cytotoxicity to leukemic cells and did not show any toxicity on immune organs. In vivo i.p. administration of HBT induced significant reduction in tumor growth but not complete regression. Sera obtained from HBT-treated mice strongly inhibited BC3A cell growth in vitro and were revealed to markedly enhance apoptosis and accompanying cell death, when compared to those from PBS-treated mice. Abundant extravasation of leukocytes, especially neutrophils, into peritoneum was observed in HBT-treated mice. Conclusions : HBT causes leukemic, BC3A cell death in vivo via apoptosis as well as in vitro, for which functional involvement of leukocytes is suggested.

• JSTS:Journal of Semiconductor Technology and Science
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• v.14 no.3
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• pp.274-283
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• 2014

In this paper, the epi layer of npn SOI HBT with n+ buried layer has been studied through Sentaurus process and device simulator. The doping value of the deposited epi layer has been varied for the npn HBT to achieve improved $f_tBV_{CEO}$ product (397 GHzV). As the $BV_{CEO}$ value is higher for low value of epi layer doping, higher supply voltage can be used to increase the $f_t$ value of the HBT. At 1.8 V $V_{CE}$, the $f_tBV_{CEO}$ product of HBT is 465.5 GHzV. Further, the film thickness of the epi layer of the SOI HBT has been scaled for better performance (426.8 GHzV $f_tBV_{CEO}$ product at 1.2 V $V_{CE}$). The addition of this HBT module to fully depleted SOI CMOS technology would provide better solution for realizing wireless circuits and systems for 60 GHz short range communication and 77 GHz automotive radar applications. This SOI HBT together with SOI CMOS has potential for future high performance SOI BiCMOS technology.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.11A
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• pp.902-911
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• 2003

Using InGaP/GaAs HBT power cells with a 2.0${\times}$20$\mu\textrm{m}$$^2$ emitter area of a unit HBT, a two stage MMIC power amplifier has been developed for IMT-2000 handsets. An active-bias circuit has been used for temperature compensation and reduction in the idling current. Fitting on measured S-parameters of the HBT cells, circuit elements of HBT's nonlinear equivalent model have been extracted. The matching circuits have been designed basically with the extracted model. A two stage HBT MMIC power amplifier fabricated using ETRI's HBT process. The power amplifier produces an 1-㏈ compressed output power(P$\_$l-㏈/) of 28.4 ㏈m with 31% power added efficiency(PAE) and 23-㏈ power gain at 1.95 GHz in on-wafer measurement. Also, the power amplifier produces a 26 ㏈m output power, 28% PAE and a 22.3-㏈ power gain with a -40 ㏈c ACPR at a 3.84 ㎒ off-center frequency in COB measurement.quency in COB measurement.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.15 no.7
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• pp.713-721
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• 2004

This paper presents a high Performance LNA based on InGaP/GaAs HBT for 5.4㎓ WAM band applications. During the past days, InGaP/GaAs HBT has been being used for mainly high power amplifiers, but InCaP/GaAs is recognized as a suitable device for RF single chip. At this point, the research about a high performance LNA based on InGaP/GaAs HBT must be preceded, and in this paper, a excellent linearity and noise characteristics LNA based on InGaP/GaAs HBT is desisted and fabricated. The LNA is integrated in new of 0.9${\times}$0.9$\textrm{mm}^2$ single chip with high Q spiral inductors and MIM capacitors. The proposed LNA is biased at current point for optimum noise figure and gain characteristics, futhermore, excellent linearity is achieved. The proposed LNA shows 13㏈ gain, 2.1㏈ noise figure, and excellent linearity in terms of IIP3 of 5.5㏈m.

• ETRI Journal
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• v.26 no.1
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• pp.61-64
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• 2004

We have explored the fabrication of an InP/InGaAs single heterojunction bipolar transistor (HBT) and a wave guide p-i-n photodiode (PD) on two kinds of double stacked layers for the implementation of an optoelectronic millimeter-wave monolithic integrated circuit (OEMMIC). We applied a photosensitive polyimide for passivation and integration to overcome the large difference between the HBT and PD layers of around $3{\mu}m$. Our experiment showed that the RF characteristics of the HBT were dependent on the location of the PD layer, while the dc performances of the HBTs and PDs were independent of the type of stacked layer used. The $F_t$ and $F_{max}$ of the HBTs on the HBT/PD stacked layer were 10% lower than those of the HBTs on the PD/HBT stacked layer.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2000.11a
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• pp.220-224
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• 2000

AlGaAs/GaAs HBT를 이용하여 1.9 GHz 대역 2단 MMIC 전력증폭기를 설계하였다. HBT의 실측 S 파라미터를 이용하여 정합회로를 설계하였으며, 목적에 따라 적절한 형태의 출력 정합 회로를 하이브리드 형태로 칩 외부에 부가할 수 있도록 설계하였다. HBT의 실측정 S 파라미터의 fitting을 통하여 비선형 등가모델을 추출하였고, load-pull 시뮬레이션으로 최대 출력 정합 임피던스를 결정하였다. 시뮬레이션 결과, 29 dBm의 출력 전력, 40 %의 전력 부가 효율, 그리고 16 dB의 전력 이득을 얻었다.

• Proceedings of the IEEK Conference
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• 1998.06a
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• pp.405-408
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• 1998

Due to the large conduction band discontinuity between emitter base, OmGaAs HBT has an advantge to enable the hot electrons to inject into the base. In this paper, InAlGaAs/InGaAs HBT with the various emitter junction gradings and the modified collectors are simulated and analyzed by HMC(hybrid monte carlo) simulator in order to find a optimal structure for the shortest transit time. A minium base transit time (.tau.$_{b}$ ) of 0.21 ps was obtained for HBT with the grading layer, which is parabolically graded from x=1.0 to x=0.5. The minimum collector transit time (.tau.$_{c}$ ) of 0.31ps was found when the collector was modified by inserting p$^{[-10]}$ and p$^{+}$ layers. Thus HBT in combination with the emitter grading and the modified collector layer showed the cut-off frequency (f$_{T}$) of 183GHz.z.z.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.32B no.5
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• pp.710-719
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• 1995

In LD driver with HBT's. the speed characteristics of HBT's are deteriorated very much mainly due to the source resistance(Rs) of the signal applied to the LD driving HBT. We improved the bandwidth of LD driver by 2-5GHz with modifications of EF buffer. Because the modified buffers are composed of EF structure, their bandwidths are decreased rapidly as Rs is increased. When Rs is large these buffers decrease the bandwidth of the LD driver rather than increase it. To solve this problem, we propose a new buffer structure which contaings new charging and discharging path for the parasitic collector capacitance of the HBT. For Rs>100${\Omega}$, it shows superior characteristics of improving bandwidth to the EF buffers. It also shows good gain characteristics.