Browsing by Author "Peng, AS"

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A fully integrated 5.2 GHz GaInP/GaAs HBT upconversion micromixer with output LC current combiner and oscillator
(2003-01-01)
Meng, CC
;
Hsu, SK
;
Peng, AS
;
Wen, SY
;
Huang, GW
A 5.2 GHz; upconversion micromixer with output LC current combiner and integrated oscillator is demonstrated in 2 mum GaInP/GaAs HBT technology in this paper. Micromixer has a single-ended input and a passive LC current combiner is used to convert mixer differential output into a single-ended output. A cross-coupled LC oscillator with oscillation frequency of 4.3 GHz; and a cascode buffer amplifier are also integrated in the same chip. The die size is 1 mm(2). The fully integrated upconversion micromixer has conversion gain of -2.5 dB, OP1dB of -12.5 dBm and 40 dB RF-IF isolation when input IF=0.9 GHz and thus output RF=5.2 GHz. The IF input return loss is better than 25 dB for frequencies up to 6 GHz: while RF output return loss is better than 12 dB for frequencies from 5.15 GHz; to 5.35 GHz.
A fully integrated 5.2 GHz GaInP/GaAs HBT upconversion micromixer with output LC current combiner and oscillator
(2003)
Meng, CC
;
Hsu, SK
;
Peng, AS
;
Wen, SY
;
Huang, GW
A 5.2 GHz upconversion micromixer with output LC current combiner and integrated oscillator is demonstrated in 2 mum GaInP/GaAs HBT technology in this paper. Micromixer has a single-ended input and a passive LC current combiner is used to convert mixer differential output into a single-ended output. A cross-coupled LC oscillator with oscillation frequency of 4.3 GHz and a cascode buffer amplifier are also integrated in the same chip. The die size is 1 mm(2). The fully integrated upconversion micromixer has conversion gain of -2.5 dB, OP1dB of -12.5 dBm and 40 dB RF-IF isolation when input IF=0.9 GHz and thus output RF=5.2 GHz. The IF input return loss is better than 25 dB for frequencies up to 6 GHz while RF output return loss is better than 12 dB for frequencies from 5.15 GHz to 5.35 GHz.
Linearity and power characteristics of SiGeHBTs at high temperatures for RF applications
(2005-07-01)
Chen, KM
;
Peng, AS
;
Huang, GW
;
Chen, HY
;
Huang, SY
In this paper, the power gain, power-added efficiency (PAE) and linearity of power SiGe heterojunction-bipolar transistors at various temperatures have been presented. The power characteristics were measured using a two-tone load-pull system. For transistors biased with fixed base voltage, the small-signal power gain and PAE of the devices increase with increasing temperature at low base voltages, while they decrease at high base voltages. Besides, the linearity is improved at high temperature for all voltage biases. However, for devices with fixed collector current, the small-signal power gain, PAE, and linearity are nearly unchanged with temperature. The temperature dependence of power and linearity characteristics can be understood by analyzing the cutoff frequency, the collector current, Kirk effect and nonlinearities of transconductance at different temperatures.