Browsing by Author "Meng, C."

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10 GHz dual-conversion low-IF downconverter with microwave and analogue quadrature
(2009-06-18)
Syu, J. -S.
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Meng, C.
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Teng, Y. -H.
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電信工程研究所
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Institute of Communications Engineering
A 10 GHz dual-conversion low-IF downconverter using 0.18-mm CMOS technology is demonstrated. The high-frequency quadrature RF and LO(1) signals are generated by broadside-coupled quadrature couplers while a two-section polyphase filter is utilised for the low-frequency LO(2) quadrature signal generation. As a result, the demonstrated downconverter achieves a conversion gain of 7 dB, IP(1dB) of -16 dBm, IIP(3) of 25 dBm and noise figure of 26 dB at a 1.8 V supply. The image-rejection ratio of the first/second image signal is 33/42 dB for IF frequency ranging from 10 to 60 MHz, respectively.
5 GHz quadrature voltage-controlled oscillator using trifilar transformers
(2008-04-24)
Syu, J. -S.
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Meng, C.
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Tsung, K. -C.
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Huang, G. -W.
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電信工程研究所
A 0.18 mm CMOS 5 GHz quadrature voltage-controlled oscillator (QVCO) is demonstrated by using trifilar transformer coupling. The trifilar transformers composed of one primary coil and two secondary coils are used to separate the gate and drain bias for output voltage swing optimisation and also replace a conventional transistor-coupling method for quadrature output generation simultaneously. As a result, the trifilar-coupling QVCO achieves 180.1 dBc/Hz figure of merit (FOM) at the supply voltage of 1.2 V. The on-chip passive single sideband upconversion mixer is also demonstrated to fairly measure the quadrature accuracy of the QVCO. Thus, a 33.7 dB sideband rejection ratio is achieved.
5.2 GHz SiGe HBT upconverter using active-inductor LC current mirror
(2006-07-20)
Wu, T. -H.
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Meng, C.
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Wu, T. -H.
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電信工程研究所
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Institute of Communications Engineering
A compact 5.2 GHz upconversion micromixer using the 0.35 mu m SiGe HBT technology is demonstrated. A bandpass and area-saving LC current mirror using the active inductor is incorporated to increase the conversion gain. The demonstrated upconverter has conversion gain of -3.5 dB, OP(1dB) of -10 dBm, and O1P(3) of 0 dBm.
5.7 GHz GalnP/GaAs HBT sub-harmonic gilbert downconverter with octet-phase LO generator
(2006-09-14)
Wu, T. -H.
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Meng, C.
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Wu, T. -H.
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電信工程研究所
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Institute of Communications Engineering
A 5.7 GHz GaInP/GaAs heterojunction bipolar transistor (HBT) sub-harmonic Gilbert downconversion mixer with octet-phase LO generator is demonstrated. The conversion gain is 15 dB, IP1dB is - 13 dBm, IIP3 is 0 dBm, and IIP2 is 24 dBm when the LO power equals 3 dBm. The measured IF quadrature output waveforms indicate that the phase difference between the in-phase and quadrature-phase output channels is only 1.3 degrees.
9.5 GHz GaInP/GaAs HBT divide-by-two frequency divider using super-dynamic D-type flip-flop technique
(2007-06-21)
Wei, H.-J.
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Meng, 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
A frequency divider with super-dynamic D-type flip-flop is demonstrated in 2 mu m GaInP/GaAs HBT (f(T) = 40 GHz) technology. By biasing the HBT devices around the peak transit-time frequency (f(T)), the operating frequency of a D-FT with ECNFP (emitter-coupled negative feedback pairs) can be improved. At a supply voltage of 5 V a divide-by-two function of 9.5 GHz is achieved.
Broadband SiGe HBT Gilbert downconverter with 1.8 to 36 GHz integrated dual Marchand balun
(2008-07-03)
Syu, J. -S.
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Meng, C.
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Yu, S. -W.
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電信工程研究所
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Institute of Communications Engineering
A broadband Gilbert downconverter with an integrated dual Marchand balun (balanced to unbalanced transformer) is demonstrated by using 0.35 mu m SiGe heterojunction bipolar transistor (HBT) technology. A dual Marchand balun consisting of a lower band balun and an upper band balun is employed in the LO stage of the downconverter to maintain balanced LO signals from 1.8 to 36 GHz. The broadband downconverter has peak conversion gain of 3 dB at RF = 3 GHz and 3 dB bandwidth of 1.8 to 20 GHz at 3.3 V DC supply.
Dynamic Range Reduction Due to RF and Image Signal Co-Existence in a Highly-Merged 2.4/5.7-GHz Dual-Band Low-IF Downconverter
(2010)
Syu, J.
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Meng, C.
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Huang, G.
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交大名義發表
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National Chiao Tung University
UWB Gilbert downconverter utilising a wideband LR-CR quadrature generator
(2009-05-07)
Syu, J. -S.
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Meng, C.
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Teng, Y. -H.
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電信工程研究所
;
Institute of Communications Engineering
An ultra-wideband (UWB) I/Q downconverter with an LR-CR quadrature generator is demonstrated using 0.35 mu m SiGe HBT technology. The I/Q outputs of this generator are always in quadrature phase at any frequency while the BJT-type active mixer inherently tolerates much LO power difference for a. at gain response. Consequently, the amplitude imbalance and phase error of the I/Q outputs are less than 1 dB and 2 degrees in the RF frequency range 3-11 GHz.
UWB Gilbert downconverter with lumped-distributed phase-inverter rat-race coupler based on Chebyshev band-broadening technique
(2011-07-21)
Wei, H. -J.
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Meng, C.
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Chang, C. -H.
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Huang, G. -W.
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電子工程學系及電子研究所
A broadband Gilbert downconverter with a miniature phase-inverter rat-race coupler is demonstrated using 0.35 mu m SiGe BiCMOS technology. By lumped-distributed and band-broadening techniques, a large shrinkage ratio with wide bandwidth of Chebyshev response can be simultaneously attained in the spiral-shape coplanar-stripline phase-inverter rat-race coupler. The area of the demonstrated lumped-distributed phase-inverter rat-race coupler is 0.65 x 0.65 mm(2) and the experimental bandwidth ranging from 2.5 to 12.5 GHz is large enough to cover the UWB bandwidth. As a result, a broadband Gilbert downconverter with the proposed coupler achieves a conversion gain of 11-12 dB, IP(1dB) of -11 dBm, IIP(3) of -1 dBm and noise figure of 16 dB from 3 to 11 GHz.
Wide-ratio broadband SiGe HBT regenerative frequency divider enhanced by differential TIA load
(2007-09-13)
Wei, H.-J.
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Meng, C.
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Chang, Y.-W.
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電信工程研究所
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Institute of Communications Engineering