Browsing by Author "Wang, SP"

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2-V-operation delta-doped power HEMT's for personal handy-phone systems
(1997-08-01)
Lai, YL
;
Chang, EY
;
Chang, CY
;
Liu, TH
;
Wang, SP
A high-efficiency and high-power-density delta-doped AIGaAs/InGaAs HEMT with low adjacent channel leakage has been developed for the digital wireless personal handy-phone system (PHS). When qualified by 1.9-GHz pi/4-shifted quadrature phase shift keying (QPSK) modulated PHS standard signals, the 2.0-V-operation HEMT with a 1-mm gate width demonstrated a power-added efficiency of 45.3% and an output power density of 105 mW/mm. This is the highest power density ever reported by the power transistors for the PHS. The state-of-the-art results for the PHS operating at 2.0 V were achieved by the delta-doped power HEMT for the first time.
2-V-operation delta-doped power HEMT's for personal handy-phone systems
(1997-08-01)
Lai, YL
;
Chang, EY
;
Chang, CY
;
Liu, TH
;
Wang, SP
A high-efficiency and high-power-density delta-doped AIGaAs/InGaAs HEMT with low adjacent channel leakage has been developed for the digital wireless personal handy-phone system (PHS). When qualified by 1.9-GHz pi/4-shifted quadrature phase shift keying (QPSK) modulated PHS standard signals, the 2.0-V-operation HEMT with a 1-mm gate width demonstrated a power-added efficiency of 45.3% and an output power density of 105 mW/mm. This is the highest power density ever reported by the power transistors for the PHS. The state-of-the-art results for the PHS operating at 2.0 V were achieved by the delta-doped power HEMT for the first time.
5 mm high-power-density dual-delta-doped power HEMT's for 3 V L-band applications
(1996-05-01)
Lai, YL
;
Chang, EY
;
Chang, CY
;
Chen, TK
;
Liu, TH
A high-power-density dual-delta-doped AlGaAs/InGaAs/GaAs high electron mobility transistor (HEMT) for personal communication applications has been developed. A 5.0 mm gate-width device operating at a drain bias of 3.0 V gave an output power over 1 W, The 1 mu m gate-length HEMT exhibited a current density of 425 mA/mm at V-gs = 0.5 V, The maximum transconductance of the device was 270 mS/mm, The effective knee voltage was as low as 0.3 V, At the class AB operation, the HEMT demonstrated an output power density of 200 mW/mm, 64% power-added efficiency and 18.2 dB linear gain at 900 MHz, This is the highest power density of a dual-delta-doped AlGaAs/InGaAs/GaAs HEMT reported to date for low voltage (3 V) wireless applications.
5 mm high-power-density dual-delta-doped power HEMT's for 3 V L-band applications
(1996-05-01)
Lai, YL
;
Chang, EY
;
Chang, CY
;
Chen, TK
;
Liu, TH
A high-power-density dual-delta-doped AlGaAs/InGaAs/GaAs high electron mobility transistor (HEMT) for personal communication applications has been developed. A 5.0 mm gate-width device operating at a drain bias of 3.0 V gave an output power over 1 W, The 1 mu m gate-length HEMT exhibited a current density of 425 mA/mm at V-gs = 0.5 V, The maximum transconductance of the device was 270 mS/mm, The effective knee voltage was as low as 0.3 V, At the class AB operation, the HEMT demonstrated an output power density of 200 mW/mm, 64% power-added efficiency and 18.2 dB linear gain at 900 MHz, This is the highest power density of a dual-delta-doped AlGaAs/InGaAs/GaAs HEMT reported to date for low voltage (3 V) wireless applications.
High-efficiency and low-distortion directly-ion-implanted GaAs power MESFET's for digital personal handy-phone applications
(1997-09-01)
Lai, YL
;
Chang, EY
;
Chang, CY
;
Tai, MC
;
Liu, TH
We report a high-efficiency and low-distortion GaAs power MESFET using direct ion implantation technology for the digital wireless personal handy-phone system (PHS). When qualified by 1.9-GHz pi/4-shifted quadrature phase shift keying (QPSK) modulated PBS standard signals, the 2.2-V-operation device with a gate width (W-g) of 2 mm exhibited a power-added efficiency (PAE) of 57.2% and an adjacent channel leakage power (P-adj) of -58 dBc at an output power of 21.3 dBm. The MESFET with the optimized direct ion implantation conditions and fabrication process achieved the highest PAE for PHS applications, The low-cost MMIC-oriented direct ion implantation technology has demonstrated the state-of-the-art results for new-generation PHS handsets for the first time.
High-performance pseudomorphic power HEMTs for low-voltage wireless communication applications
(1996)
Lai, YL
;
Chan, EY
;
Chang, CY
;
Liu, TH
;
Wang, SP
A high-performance pseudomorphic high electron mobility transistor (HEMT) with high output power density and high power-added efficiency for low-voltage wireless communication applications has been developed. This paper describes the de and microwave performance of the pseudomorphic AlGaAs/InGaAs HEMT developed. The 1 um gate-length HEMT exhibited a maximum drain current of 470 mA/mm at V-gs = +1.0 V. The maximum transconductance of the device was 280 mS/mm. At a drain bias of 3.0 V and a measurement frequency of 900 MHz, the 2mm-wide HEMT demonstrated an output power of 26.1 dBm ( a power density of 204 mW/mm) and a power-added efficiency of 65 % under the class AB condition while an output power of 26.7 dBm (234 mW/mm) and a power-added efficiency of 60 % were obtained under the class A condition. The developed pseudomorphic power HEMT developed achieves the highest output power density ever reported among the GaAs devices operating at 3.0 V.
High-power-density and high-efficiency atomic-planar-doped AlGaAs/InGaAs quantum-well power high-electron-mobility transistors for 2.4 V medium-power wireless communication applications
(1997-03-01)
Lai, YL
;
Chang, EY
;
Chang, CY
;
Liu, TH
;
Wang, SP
A high-power-density and high-efficiency molecular-beam-epitaxy-grown atomic-planar-doped AlGaAs/InGaAs quantum-well power high-electron-mobility transistor (HEMT) was developed for low-voltage medium-power wireless communication applications. The HEMT exhibited a maximum drain current of 420 mA/mm and a maximum transconductance of 275 mS/mm. A two-dimensional electron gas with a high sheet charge density and a high electron mobility in the InGaAs quantum well contributed to the high current density and high transconductance of the HEMT and enhanced the device power performance at low operating voltage. An output power density of 177 mW/mm and a power-added efficiency of 61% were achieved by the 2 mm HEMT at a drain voltage of 2.4 V and a frequency of 900 MHz. At 2.1 V drain voltage and 2.4 GHz, frequency, the device demonstrated an output power of 24.4 dBm and a power-added efficiency of 57.4%. An adjacent channel leakage power of -55 dBc was attained for the 1.9-GHz pi/4-shifted quadrature phase shift keying modulation when the output power was 22.2 dBm and the drain voltage was 2.4 V.