Browsing by Author "Meng, C. C."

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2.4/5.7-GHz Dual-Band Dual-Conversion Low-IF Downconverter Using 0.35 mu m SiGe HBT Technology
(2010)
Syu, J. -S.
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Meng, C. C.
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Yu, S. -W.
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Huang, G. -W.
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電機工程學系
A 2.4/5.7-GHz dual-band dual-conversion low-IF downconverter is demonstrated using 0.35 mu m SiGe heterojunction bipolar transistor (HBT) technology. The first image signal is shifted away from the IF band by a complex Weaver architecture while the second image signal is eliminated by a complex Hartley architecture. The downconverter achieves a 45/44-dB image-rejection ratio of the first image (IRR1) and a 50/48-dB image-rejection ratio of the second image (IRR2) for 2.4/5.7-GHz modes, respectively, when IF frequency ranges from 20 to 40 MHz.
4-GHz fully monolithic SiGe HBT QVCO using superharmonic coupling topology
(2006)
Tseng, S. C.
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Meng, C. C.
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Chang, Y. W.
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Huang, G. W.
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電信工程研究所
This paper demonstrates a 4-GHz monolithic SiGe heterojunction bipolar transistor (HBT) quadrature voltage controlled oscillator (QVCO) using superharmonic coupling topology. The quadrature VCO at 4.17 GHz has phase noise of -116 dBc/Hz at lMHz offset frequency, output power of -6 dBm and the figure of merit (FOM) -179 dBc/Hz. The core current consumption is 3.2 mA at 3V supply voltage. The die size is about 1.4 mm. x 1.2 mm.
4-GHz low-phase-noise transformer-based top-series GaInP/GaAs HBT QVCO
(2006)
Meng, C. C.
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Tseng, S. C.
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Chang, Y. W.
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Su, J. Y.
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Huang, G. W.
The fully integrated GaInP/GaAs heterojunction bipolar transistor (HBT) transformer-based top-series quadrature voltage controlled oscillator (QVCO) is demonstrated at 4 GHz. The transformers on the semi-insulating GaAs substrate possess good electrical properties at high frequencies. The quadrature VCO at 4.1 GHz has phase noise of -120 dBc/Hz at 1MHz offset frequency, output power of 2 dBm and the figure of merit (FOM) -178 dBc/Hz.
C-band fully integrated SiGe HBT superharmonic QVCO
(2007-04-01)
Tseng, S. C.
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Meng, C. C.
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Chang, Y. W.
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Huang, G. W.
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電信工程研究所
This paper demonstrates a 4-GHz monolithic SiGe heterojunction bipolar transistor quadrature voltage-con trolled oscillator (QVCO) using superharmonic coupling topology. The QVCO at 4.17 GHz has phase noise of -116 dBc/Hz at 1 MHz offset frequency, output power of -6 dBm, and the figure of merit - 179 dBc/Hz. The core current consumption is 3.2 mA at 3 V supply voltage. The die size is about 1.4 mm X 1.2 mm. (c) 2007 Wiley Periodicals. Inc.
Comparisons of complex permittivity measurements using free-space and waveguide Fabry-Perot resonators at E/W-band frequencies
(2006)
Meng, C. C.
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電信工程研究所
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Institute of Communications Engineering
Dielectric materials with the real relative permittivity ranging from 5 to 16 are studied thoroughly at 60-110 GHz using the free-space quasi-optical and waveguide Fabry-Perot interferometer measurement techniques. The optical n and k constants can be obtained accurately even though the undesired standing waves resulting from the imperfection interfaces in the measurement system cause strong spikes in the measured Fabry-Perot interference fringe pattern.
Gain enhancement techniques for CMOS LNA and mixer
(2006-10-01)
Su, J. -Y.
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Meng, C. C.
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Li, Y. -H.
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Tseng, S. -C.
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Huang, G. -W.
Two major techniques for gain improvement of the CMOS low noise amplifier (LNA) and mixer are presented. First, the inductive interstage matching is applied to design a cascode amplifier for increasing the power transfer between the common source (CS) and common gate (CG) stages. Second, a super source follower (SSF) is utilized in a P-type micromixer for increasing the conversion gain of the mixer. A series of investigations are performed for demonstrating the feasibilities of the proposed techniques. The LNA and mixer designs based on the proposed techniques are realized using 0.35 im IP4M CMOS technology. Then their measured results are compared with those of a preliminary design, which fully integrates a conventional cascode amplifier and a P-type micromixer. The gain of the LNA is increased 2.1 dB and the noise figure is maintained at the same value of the preliminary design. On the other hand, the conversion gain of the super source follower (SSF) of the micromixer output is improved about 9.5 dB. Such improvements reveal great potential of the proposed design techniques on the gain enhancement for the LNA and mixer. Then, the measured results of the preliminary design show the return-loss of 25 dB, the isolation of better than 30 dB, and the conversion gain of 4.8 dB in the 2.4 GHz ISM hand. (C) 2006 Wiley Periodicals, Inc.
GaInP/GaAs HBT wideband transformer Gilbert downconverter with low voltage supply
(2008-01-17)
Tseng, S. -C.
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Meng, C. C.
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Wu, C. -K.
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電信工程研究所
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Institute of Communications Engineering
A low-voltage wideband downconverter along with an integrated transformer RF balun using the 2 mu m GaInP/GaAs HBT technology is demonstrated. This transformer is a symmetric type and plays a role as a single-to-differential balun. Without the parasitic between the transformer and the substrate, the transformer can work at higher frequencies. This transformer downconverter operates from 1.5 to 14 GHz with around 20 dB conversion gain and 1.8 GHz IF 3 dB bandwidth. The frequency range of the mixing operation is wide and covers the digital video broadcasting via satellite (DVB-S) bands. This mixer is therefore useful for DVB-S applications.
High-gain high-isolation CMFB stacked-LO subharmonic Gilbert mixer using SiGe BiCMOS technology
(2007-05-01)
Wu, T. H.
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Meng, C. C.
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Huang, G. W.
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電信工程研究所
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Institute of Communications Engineering
A 5.2-GHz SiGe BiCMOS stacked-LO-stage CMFB (common made feedback) subharmonic mixer is demonstrated in this article. The stacked-LO-stage and the active loads are used to improve the 2LO-RF isolation and the conversion gain, respectively. The SiGe mixer includes five levels of transistors stacked together at the supply voltage of 3.3 V because of the low knee-voltage characteristic of the SiGe HBTs (heterojunction bipolar transistors). The mixer demonstrated achieves 23 dB conversion gain and -78 dB 2LO-RF isolation. (c) 2007 Wiley Periodicals, Inc.
INTERCONNECTION LOSS FROM SUBSTRATE EFFECTS ON LNA PERFORMANCE AND DESIGN ACCURACY
(2009-01-01)
Tseng, S. -C.
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Meng, C. C.
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Liao, H. -Y.
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Lin, Y. -C.
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Teng, Y. -H.
A 5.2 GHz 0.18-mu m SiGe BiCMOS low noise amplifier is implemented with guided-wave interconnections in this letter. These interconnections reduce the substrate skin and proximity effects and hence are suitable for high frequency circuits. The guided interconnections bring 1.7-dB gain and 0.55-dB noise figure enhancement for the low noise amplifier. In addition, accurate and simple design methodology relies on the complete models of components and interconnections when the poststimulation from the rc extraction is not enough for the high,frequency circuit design. The measurement results give excellent agreements with the schematic simulation. (C) 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 144-146, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23968
Low-phase-noise transformer-based top-series QVCO using GaInP/GaAs HBT technology
(2007-01-01)
Meng, C. C.
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Tseng, S. C.
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Chang, Y. W.
;
Su, J. Y.
;
Huang, G. W.
The fully integrated GaInP/GaAs heterojunction bipolar transistor, transformer-based top-series quadrature voltage controlled oscillator (QVCO) is demonstrated at 4 GHz. The transformers on the semi-insulating GaAs substrate possess good electrical properties at high frequencies. The QVCO at 4.1 GHz has phase noise of - 120 dBc/Hz at 1 MHz offset frequency, output power of 2 dBm and the figure of merit -178 dBc/Hz. (c) 2006 Wiley Periodicals, Inc.
Performance enhancement of the nMOSFET low-noise amplifier by package strain
(2007-01-01)
Hua, W. -C.
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Chang, H. -L.
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Wang, T.
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Lin, C. -Y
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Lin, C. -P.
The package strain improves the noise figure (NF) of the low-noise amplifier (LNA). The maximum noise reduction is similar to 0.53 dB (13%) at the operating frequency of 2.4 GHz under the biaxial tensile strain of 0.037%. The NIT reduction of the strained LNA is mainly due to the enhanced transconductance and cutoff frequency of the individual nMOSFET device under the same strain and bias conditions.
RF characteristics of BJT devices with selectively or fully ion-implanted collector
(2005)
Meng, C. C.
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Su, J. Y.
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Tsou, B. C.
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Huang, G. W.
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電信工程研究所
A selectively ion-implanted collector (SIC) is implemented in a 0.8 um BiCMOS process to improve the RF characteristics of the BJT devices. The SIC BJT device has better ft and fmax than the FIC (fully ion-implanted collector) BJT device because the extrinsic base-collector capacitance is reduced by the SIC process. The fmax is 9.5GHz and ft is 7.8 GHz for the SIC BJT device while the fmax is 7.2 GHz and fmax is 4.5 GHz for the FIC BJT device when biased at Vce=3.6 V and Jc=0.09 mA/um(2). The nois parameters are the same for both BJT devices but the associated gain is higher for the SIC BJT device.
Sige BiCMOS subharmonic Gilbert mixer using lumped-element ratrace couplers
(2007-08-01)
Tseng, S.-C.
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Meng, C. C.
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Huang, G.-W.
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電信工程研究所
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Institute of Communications Engineering
A single-ended down-conversion subharmonic miser is implemented using 0.35-mu m SiGe BiCMOS technology. Two lumped-element rat-race couplers are applied to generate differential LO and RF signals. This single-ended rat-race mixer has the conversion gain of 25 dB, -90-dB 2xLO-to-RF isolation and -78-dB 2xLO-to-IF isolation at the RF frequency of 10 GHz. The input return loss is about -10 dB. (c) 2007 Wiley Periodicals, Inc.
SSH and SHHGaInP/GaAs HBT divide-by-3 prescalers with true 50% duty cycle
(2006-07-06)
Tseng, S. C.
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Meng, C. C.
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Chen, W. Y.
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電信工程研究所
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Institute of Communications Engineering
Two 50% duty cycle divide-by-3 prescalers - sample-sample-hold (SSH) and sample-hold-hold (SHH) prescalers - in the 2 pm GaInP/GaAs heterojunction bipolar transistor (HBT) technology are realised. Current switchable emitter couple logic D flip-flops are employed to form both prescalers. The proposed SHH prescaler functions up to 2.6 GHz while the SSH prescaler operates from DC to 1.75 GHz. The maximum operating frequency of the SHH prescaler is enhanced about 50% compared with that of the SSH prescaler owing to better signal synchronisation.