S-band GaN based low noise MMIC amplifier design and characterization
Author
Taşcı, Muhittin
Advisor
Özbay, Ekmel
Date
2019-02Publisher
Bilkent University
Language
English
Type
ThesisItem Usage Stats
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Show full item recordAbstract
Low Noise Amplifiers (LNA) are widely preferred components in receiver frontend
modules. The received signal level is generally very low and amplifying it without
adding too much noise is very crucial in communication systems.
In this thesis study design, fabrication and test of three Gallium Nitride (GaN)
High Electron Mobility Transistor (HEMT) based Monolithic Microwave Circuit
(MMIC) LNAs are presented. Inductive source feedback topology is used to
obtain both better input return loss and noise figure. All three designs achieve
higher than 20 dB gain, better than 10 dB input return loss and their noise figure
values are 2 dB, 1.5 dB and 1 dB in S-band. High resistive gate biasing is utilized
at third design to increase input power handling. Size reduction is very important
in MMIC technology. The first design is 3 x 5 mm and the second design is 2 x
3.5 mm, % 46 size reduction is achieved. In GaN technology controlling SiN layer
thickness is very problematic and this fabrication step affects capacitor values.
The second and third LNA designs presented in this research, matching circuitries
and implicitly overall characteristics are not in
uenced too much by a change of
capacitor values. Targeted bandwidth is 2.7-3.5 GHz, achieved frequency range
is 1.5 GHz (from 2.5 GHz to 4 GHz). The three LNA designs have 28.1 dBm,
33.4 dBm, and 35.9 dBm output third-order intercept point respectively. Output
powers at 1-dB compression points are 18.2 dBm, 23.4 dBm and 25.9 dBm. For
all three LNA designs, group delay is less than 0.3 nanoseconds.