Browsing by Author "Chen, GJ"

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A low noise composite-channel metamorphic HEMT for wireless communication applications
(2003)
Lu, CY
;
Chen, KS
;
Lee, HM
;
Chang, EY
;
Chen, SH
A composite-channel Metamorphic high electron mobility transistor (MHEMT) was developed for low noise high linearity application. The MHEMT was grown by Molecular Beam Epitaxy (MBE) on GaAs substrates with InAlAs graded buffer. The composite-channel layers in the MHEMT include a top In0.55Ga0.45As layer, a middle In0.67Ga0.33As layer, and a bottom In0.55Ga0.45As layer. The design of this structure provides better electron confinement in the channel with less impact ionization as compared to conventional dual delta doped MHEMTs. This results in devices with higher linearity and drain to gate voltage as compared to the conventional metamorphic HEMTs. The 0.25x160 mum(2) device with the novel channel structure exhibits a maximum frequency of oscillation f(max) of 290 GHz and a current gain cut-off frequency f(t) of 110 GHz. The noise figure of the device at 6 GHz is 0.23 dB and the associated gain was 15.06 dB. The IP3 of the device at 6 GHz is 19.67 dBm. The composite channel metamorphic HEMT shows great potential for high linearity and low noise application at high frequencies.
Composite-channel metamorphic high electron mobility transistor for low-noise and high-linearity applications
(2004-07-01)
Chang, EY
;
Lin, YC
;
Chen, GJ
;
Lee, HM
;
Huang, GW
A metamorphic high-electron-mobility transistor (MHEMT) with In0.55Ga0.45As/In0.67Ga0.33As/In0.55Ga0.45As composite channel layers was developed for low-noise and high-linearity applications. The use of: a composite channel results in high electron mobility and good confinement of electrons in the channel region which are the desired characteristics of low-noise and high-linearity devices. The noise figure of the 0.25 x 160 mum(2) devices is 0.23 dB with 15.06 dB associated gain, and the output third-order intercept point (IP3) is 18.67 dBm at 6 GHz. The device shows great potential for high-linearity and low-noise applications at high frequencies.
InGaP/InGaAs PHEMT with high IP3 for low noise applications
(2004-06-10)
Lin, YC
;
Chang, EY
;
Chen, GJ
;
Lee, HM
;
Huang, GW
A low noise InGaP/InGaAs pseudomorphic high-electron-mobility transistor (PHEMT) with high IN was developed. The device utilises InGaP as the Schottky layer to achieve a low noise figure and uses AlGaAs as the spacer to reform the electron mobility and contains dual delta doped layers to improve the device linearity.