Browsing by Author "Kao, Hsuan-Ling"

Now showing 1 - 5 of 5

Analysis of the back-barrier effect in AlGaN/GaN high electron mobility transistor on free-standing GaN substrates
(2020-01-25)
Liu, Xinke
;
Wang, Hao-Yu
;
Chiu, Hsien-Chin
;
Chen, Yuxuan
;
Li, Dabing
The effect of AlGaN back-barrier on AlGaN/GaN high electron mobility transistors (HEMTs) using freestanding GaN wafer has been investigated in this work. With the introducing back-barrier structure, the leakage path underneath the buffer (native nitrogen-vacancies and GaOx compounds of the HVPE-grown free-standing GaN surface) layer can be suppressed by lift-up the conduction band. As compared with AlGaN/GaN HEMTs on SiC wafer, AlGaN/GaN HEMTs on free-standing GaN wafer show enhanced drain current ( 700 mA/mm), improved transconductance (143 mS/mm), less current collapse (12%), higher current gain cut-off frequency (13 GHz), and maximum stable gain cut-off frequency (24 GHz), which is attributed to the higher epi quality layer on free-standing GaN wafer. (C) 2019 Elsevier B.V. All rights reserved.
High Performance RF Passive Devices and Noise-Shielding MOSFET on IC-Standard Si Wafer for Sub-THz Applications
(2013)
Chin, Albert
;
Kao, Hsuan-Ling
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
The operation frequency of a MOSFET is approaching THz as continuously scaling down into 1X nm. Nevertheless, the very high power loss of transmission line on IC-Standard Si wafer (similar to 5 dB/mm at 110 GHz) is the fundamental limitation for Si-based sub-THz IC. Using a simple method to translate standard 10 Omega-cm low resistivity into semi-insulating, very low loss transmission line and broad filters have been realized on Si wafer to 110 GHz, with performance near ideal devices by EM design. The noise coupling of CPW-layout RF MOSFET can also be filtered using a microstrip line design, and a low min. noise figure (NFmin) of 0.5 dB at 10 GHz was measured in a 90 nm MOSFET.
High-performance radio frequency passive devices on plastic substrates for radio frequency integrated circuit application
(2007-04-01)
Hung, Bing-Fang
;
Chen, Chia-Chung
;
Kao, Hsuan-Ling
;
Chin, Albert
;
電子工程學系及電子研究所
High-performance passive RF devices were fabricated on insulating plastic substrates. These passive devices included inductors, low-loss coplanar waveguide (CPW) and microstrip transmission lines, 30 GHz narrow-band filters, and 25 GHz CPW ring resonators. The characteristics of these devices agreed well with those of ideal devices, as predicted by electromagnetic simulations.
Improved Radio Frequency Power Characteristics of Complementary Metal-Oxide-Semiconductor-Compatible Asymmetric-Lightly-Doped-Drain Metal-Oxide-Semiconductor Transistor
(2010)
Chang, Tsu
;
Kao, Hsuan-Ling
;
Chen, Y. J.
;
Chin, Albert
;
電子工程學系及電子研究所
We have characterized and modeled the radio frequency (RF) power performance of a 0.18 mu m asymmetric-lightly-doped-drain metal-oxide-semiconductor field-effect transistor (LDD MOSFET). In comparison with the conventional 0.18 mu m MOSFET, this asymmetric-LDD device shows a larger power density of 0.54 W/mm, and 8 dB better adjacent channel power ratio (ACPR) linearity at 2.4 GHz from the improved twice DC breakdown voltage of 6.9 V. These significant improvements of RF power performance in the asymmetric-LDD transistor are important for the medium RF power amplifier application. (C) 2010 The Japan Society of Applied Physics
V-Band Push-Push VCO using Slow-Wave CPW Resonators for Low Phase Noise Reduction
(2013-10-01)
Ke, Po-Yu
;
Chiu, Hsien-Chin
;
Huang, Fan-Hsiu
;
Kao, Hsuan-Ling
;
Chien, Feng-Tsun
This article presents a design for two fully integrated millimeter-wave V-band push-push voltage-controlled oscillators (VCOs) implemented in a 150-nm pHEMT process is presented. Both use slow-wave coplanar waveguide (CPW) structure transmission line resonators, instead of a lumped LC tank, to provide an extended output frequency range and relatively low phase noise (PN). A LC tank with and without slow-wave features is used in the two VCO circuits. The measured results for manufactured chips are compared. The VCO with the slow-wave feature demonstrates a lower PN of -104.5 dBc/Hz at a 1-MHz offset frequency. A comparison of the designs with and without a slow-wave VCO shows that the VCO design with slow wave demonstrates lower average PN of approximately 8 dBc at an offset frequency of 1 MHz. Varactor adjustment of the oscillation frequencies for the two VCOs gives 53.2 to 57.1 GHz for the VCO without slow wave and 53.8 to 55.4 GHz for the VCO with slow wave. The two VCOs are developed for use in licensed V-band transceiver systems. (C) 2013 Wiley Periodicals, Inc.