Browsing by Author "Chao, Tzu-Yuan"

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A 37.5-mW 8-dBm-EIRP 15.5 degrees-HPBW 338-GHz Terahertz Transmitter Using SoP Heterogeneous System Integration
(2015-02-01)
Li, Chun-Hsing
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Chao, Tzu-Yuan
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Lai, Chih-Wei
;
Chen, Wei-Cheng
;
Ko, Chun-Lin
A low-cost terahertz transmitter is proposed by using system-on-package (SoP) heterogeneous system integration. A signal source in 40-nm CMOS is integrated with an antenna array on a Benzocyclobutene carrier through a broadband low-loss terahertz interconnect. The signal source adopting triple-push oscillator topology is able to produce a differential output without any additional balun circuit. Hence, the power consumption and the chip area can be reduced. The antenna array containing 50 patch antennas is differentially excited to give simulated directivity, efficiency, and antenna gain as high as 22.6 dB, 88%, and 22 dBi, respectively, at 335 GHz. The terahertz interconnect employs a resonator coupling technique to provide low-loss and broadband performance while occupying a small area. Measured results show that the proposed terahertz transmitter can work at 338.4 GHz with equivalent isotropically radiated power (EIRP) of 8.0 dBm while consuming only 37.5 mW from a 1-V supply. The measured half-power beam-width can be as narrow as 15.5 degrees. The EIRP can be further raised to 9.5 dBm as the supply V-DD is increased to 1.3 V. The CMOS chip only occupies an area as small as 0.028 mm(2). All of the design efforts enable the proposed terahertz transmitter to feature in small form factor, low power dissipation, low cost, and high performance. To the best of the authors\' knowledge, this is the most compact, lowest power, lowest cost, and high-performance SoP-based terahertz transmitter reported thus far.
A Polar Modulated Tri-band Power Amplifier Using Flexible Substrate Based MEMS Switches
(2010-01-01)
Lai, Chung-Min
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Chao, Tzu-Yuan
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Tsou, Wen-An
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Chou, Mei-Fen
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Cheng, Yu-Ting
In this work, the phase compensation techniques by means of self-biasing control and an additional tuning capacitor for polar modulated tri-band Class-E power amplifier is proposed. The tri-band power amplifier operating at 2.3 similar to 2.7/3.3 similar to 3.8/5.1 similar to 5.8 GHz for WLAN and WiMAX applications adjusts low loss Micro-Electro-Mechanical-Systems (MEMS) switches to select the matching networks. The improvement of phase distortion and system relative constellation error (RCE) is 36.4 degrees and 8.9dB, respectively. Simulation results shows that the maximum power-added efficiency (PAE) of 34.9%, drain efficiency of 37.3%, and output power of 18.8dBm from 2.8V supply can be achieved in 0.18 mu m CMOS Technology.
An Interconnecting Technology for RF MEMS Heterogeneous Chip Integration
(2010-04-01)
Chao, Tzu-Yuan
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Li, Chun-Hsing
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Chen, Yang Chuan
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Chen, Hsin-Yu
;
Cheng, Yu-Ting
An interconnecting technology using a Au-Au thermocompressive bond has been successfully developed for microelectromechanical system (MEMS) heterogeneous chip integration in this paper. The Daisy chain and RF transition structures are both designed and fabricated for the electrical characterization of the interconnect scheme. Measured dc contact resistance is about 14 +/- 5 m Omega for the bonding interface of Ni (1 mu m)/Au (0.4 mu m)/Au (0.4 mu m)/Ni (1 mu m) with a pad size of 40 mu m in diameter. The electrical transition between two chips, which have coplanar waveguides (CPWs) and microstrip lines, respectively, can be well interconnected with less than -15 dB return loss and -1.8 dB insertion loss up to 50 GHz without implementing complex structure designs and extra impedance matching networks in the transition by employing this technology. Meanwhile, it is found that the mechanical strength for the interconnecting bond can be as large as 100 MPa. A low-power RF low-noise amplifier has been successfully designed, fabricated, and utilized in this paper to demonstrate the feasibility of the interconnecting technology for RF MEMS heterogeneous chip integration by integrating a Taiwan Semiconductor Manufacturing Corporation 0.18-mu m RF complimentary metal-oxide-semiconductor chip with a silicon carrier, where high Q MEMS inductors are fabricated and utilized for good circuit performance in terms of excellent impedance matching, power gain, and gain flatness.
Broadband flip-chip interconnects for millimeter-wave Si-carrier System-on-Package
(2007)
Li, Chun-Hsing
;
Fu, Chang Tsung
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Chao, Tzu-Yuan
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Kuo, Chien-Nan
;
Cheng, Y. T.
A flip-chip interconnect is proposed to achieve good electrical performance applicable to millimeter-wave applications. By Au-Au thermocompression technique, the transition structure provides continuity of characteristic impedance from the on-carrier CPW line to the on-chip microstrip tine, as well as smooth current flow. Parameter optimization further indicates that the tapered reference ground connection is insensitive to the frequency response. Characterization of the structure is conducted by the THUR-REFLECT-LINE (TRL) calibration technique to test the flip-chip interconnects up to 50GHz. Measurement results show that return loss is better than 15dB and insertion loss smaller than 1.7dB up to 50GHz. The broadband transition structure is suitable for high frequency application without any external matching network.
CMOS THz Transmissive Imaging System
(2014)
Yan, Tzu-Chao
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Li, Chun-Hsing
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Lai, Chih-Wei
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Chen, Wei-Cheng
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Chao, Tzu-Yuan
This paper presents a THz imaging system composed of a signal source and a signal sensor in CMOS technology The signal source integrates a 338 GHz oscillator in 40-nm CMOS and an antenna array on a Benzocyclobutene (BCB) carrier using the SoP (System-on-Package) technique. The measured EIRP achieves +8 dBm. The signal sensor is implemented in 0.18 mu m CMOS. The measured maximum responsivity is 632 kV/W at 332 GHz. The signal source and signal sensor consume dc power of 37.5 mW and 7.92 mW, respectively. The resolution of the proposed THz imaging system is 4 mm.
Electronic THz Transmissive Imaging System
(2015)
Chen, Wei-Cheng
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Lai, Chih-Wei
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Yan, Tzu-Chao
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Li, Chun-Hsing
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Chao, Tzu-Yuan
An electronic THz transmissive imaging system is presented in this work. This system is composed of a CMOS signal source, a CMOS signal sensor, lenses, and commercial electronic chopping components. The output frequency of the signal source is 339 GHz, and the responsivity of the signal sensor is 200 kV/W. The total dc power consumption of those CMOS circuits is 91.02 mW. Using electronic chopping at the frequency up to 100 kHz helps improve the system dynamic range and makes imaging feasible. The resolution of the realized imaging system achieves 2 mm.
Heterogeneous Chip Integration Process for Flexible Wireless Microsystem Application
(2011-03-01)
Chao, Tzu-Yuan
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Liang, Chia-Wei
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Cheng, Y. T.
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Kuo, Chien-Nan
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電子工程學系及電子研究所
This paper presents a low-cost heterogeneous integration technology combining the previously developed bumpless radio-frequency (RF) system-on-a-package scheme with a special surface cleaning process to assemble a complementary metal-oxide-semiconductor chip with an organic substrate (SU-8/polydimethylsiloxane) by low-temperature Au-Au thermocompressive bonds (< 200 degrees C) for flexible wireless microsystem fabrication. The RF performance of -15 dB return loss and -0.25 dB insertion loss at 40 GHz and above 6 MPa bonding strength of a microstrip-to-coplanar-waveguide interconnect transition between the chip and the substrate make the technology practical for flexible wireless microsystem integration.
SU-8 serial MEMS switch for flexible RF applications
(2011-02-01)
Chao, Tzu-Yuan
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Hsu, M. C.
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Lin, C-D
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Cheng, Y. T.
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電子工程學系及電子研究所
This paper presents a novel SU-8 micromachining process for MEMS series switch fabrication. The switch is designed with a clamped-clamped SU-8 (5 mu m)/Cu (2 mu m)/SU-8 (3 mu m) beam structure driven by electrostatic force, which is fabricated on a silicon substrate with a resistivity of similar to 5 Omega cm. Experimental results show that the switch can exhibit better than -4.48 dB insertion loss and -28.2 dB isolation up to 12 GHz. Such a large insertion loss is mainly caused by substrate loss which can be further reduced down to -0.75 dB as long as the substrate resistivity is increased up to 100 Omega cm.
SYNTHESIS AND DEVICE FABRICATION OF CU-NI NANOCOMPOSITE FOR LOW POWER MAGNETIC MICROACTUATION
(2007)
Huang, Yu Wen
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Chao, Tzu-Yuan
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Cheng, Y. T.
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電子工程學系及電子研究所
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Department of Electronics Engineering and Institute of Electronics
This paper presents a Cu-Ni nanocomposite film and related CMOS compatible fabrication process using alkaline noncyanide based copper plating solution for low power magnetic microactuation application. The magnetic properties of Cu can be modified from diamagnetism to ferromagnetism via the incorporation of Ni nanoparticles into a Cu matrix to form a Cu-Ni nanocomposite film. Experimental results show that about 9% power consumption reduction of magnetic microactuation could be realized while the actuated coil is made of the Cu-Ni nanocomposite instead of pure Cu. The effective power reduction can be attributed to the magnetic flux density intensification inside the coil.
WAFER-LEVEL CHIP SCALE FLEXIBLE WIRELESS MICROSYSTEM FABRICATION
(2011)
Chao, Tzu-Yuan
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Cheng, Y. T.
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電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
The paper demonstrates a low-cost flexible wireless microsystem fabrication technology combining the previously developed bumpless RFSOP scheme [1,2] with a special surface cleaning process to assemble a CMOS chip with an organic substrate (SU-8/PDMS) by Au-Au thermocompressive bonds (<200 degrees C). About -15dB return loss and -0.8dB insertion loss @ 40GHz interconnecting structure and above 6MPa bonding strength make the technology practical for flexible wireless microsystem integration. Besides, taking advantage of chemical inertia of Au, a wafer-level sacrificial release process is performed for the low-cost fabrication.