الفهرس 
COUPLED LINES AND MIxED MODE ANALYSIS TECHNIQUEOnly 14 pages are availabe for public view
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Abstract
Balun continues to playa critical role in RF and microwave
systems that employ link between symmetrical circuits and
asymmetrical circuits. Several balun configuration have been
proposed to achieve the appropriate applications requirements.
There are tradeoff between the balun size, bandwidth, impedance
transformations and fabrication techniques.
In this thesis, two previously proposed coupled line baluns are
studied namely the five sections coupled microstrip line balun and
three sections coupled line balun where suspended coupled line are used for high even mode impedance. They are simulated,
optimized, fabricated and measured. The optimized baluns are
compared with previous results.
Microstrip line and coupled line with defected ground
structures are also studied. The structures are simulated with
commercial EM simulator. The effect of varying the defected
ground structure parameters, as well as the coupled line
parameters, on the coupled line characteristics are investigated. A
multi-section coupled line balun with defected ground structure is
proposed. The proposed balun is examined. The balun is
optimized, fabricated and measured. The obtained bandwidth is
112% Fo, the center frequency of operation, with 0.5 dB
amplitude balance and 180o± 40 phase difference.