X-band low phase noise mmic vco & high power mmic spdt design
Author(s)
Advisor
Özbay, EkmelDate
2014Publisher
Bilkent University
Language
English
Type
ThesisItem Usage Stats
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Abstract
Generally the tuning bandwidth (BW) of a VCO is smaller than the tuning BW
of the resonant circuit itself. Using proper components with right topology can
handle this problem. In order to overcome this problem and improve the tuning
BW of the VCO, common-base inductive feedback topology with Gallium
Arsenide (GaAs) Heterojunction Bipolar Transistor (HBT) is used and an optimized
topology for tank circuit is selected to minimize the effect of bandwidth
limiting components. Designed VCO with this topology achived -117 dBc/Hz at
1 MHz offset phase noise with 9-13 dBm output power between 8.8-11.4 GHz
band. Second part of the thesis composed of Single Pole Double Throw (SPDT)
RF Switch design. From mesa resistors to SPDT fabrication, everything is fabricated
using Bilkent University NANOTAM Gallium Nitride (GaN) on Silicon
Carbide (SiC) process. Switching HEMTs are fabricated to generate a model to
design SPDTs and the final design works between DC-12 GHz with less than 1.4
dB insertion loss (IL), -20 dB isolation and 14.5 dB return loss (RL) at worst
case. The power handling of the switches are better than 40 dBm at output with
0.2 dB compression, which is measured with continuous wave (CW) signal at 10
GHz.