an inductor-loaded micro strip directional coupler for directivity enhancement
TRANSCRIPT
04/10/23 TCE MADURAI 1
An Inductor-Loaded Microstrip Directional Coupler for Directivity Enhancement
IEEE MICROWAVE AND WIRELESS COMPONENTS, VOL., 19 NO. 6 JUNE 2009.
SEMINAR II
Presented ByS R Tamilarasan
10N22, TCE MADURAI.
04/10/23 TCE MADURAI 2
Content.
--> Introduction--> Basic --> Literature survey--> Objective--> Methodology--> Reference
04/10/23 TCE MADURAI 3
Introduction
The advance in the research felid has made it possible to design a coupler in the high directivity..
Loading shunt Inductance at the end of two conductor will increases the directivity..
04/10/23 TCE MADURAI 4
BASIC
Transmission
Stripline Microstripline waveguide
•Hollow region •High power transmission..
•Conductor are surrounded by same type of material..•High power transmission..•Same permittivity..
•Conductor are surrounded by a different dielectric material...•Low power transmission..•Different permittivity..•Damages to the substrate
04/10/23 TCE MADURAI 5
BASIC
Passive component.. Shunt inductor.. Improve directivity… Inhomogeneous
dielectric.. parallel coupled
microstrip..
04/10/23 TCE MADURAI 6
Techniques………………….<+> The gap between two conductor..<+> Adding lumbbed capacitance (or) inductance at each end ..<+> selecting two or more different permittivity materials..
04/10/23 TCE MADURAI 7
Method
Loading the coupler with capacitor. Null isolation. Phase velocities.
10dB directional coupler at 0.9GHz. Directivity 38dB. Application is GSM…
04/10/23 TCE MADURAI 8
Why we need capacitance?
• Inhomogeneous dielectric…
• Odd and Even mode phase velocity..
• Manifest poor directivity..
• Directivity decreases..• Permittivity increases..
04/10/23 TCE MADURAI 9
Literature survey……
• Second method is analyzed…
• Quadrature directional coupler…
• Capacitance appox. Is nearly true for tight coupling..
• Center frequency lower..
• Loose coupling..
• This paper for ideal directivity using symmetry equivalent circuit..
04/10/23 TCE MADURAI 10
Equivalent circuits….
04/10/23 TCE MADURAI 11
Model
04/10/23 TCE MADURAI 12
The matrix determination of the odd mode representation is given by,
The reduced odd mode characteristic impedance is given by
The compensation capacitance formula be,
04/10/23 TCE MADURAI 13
The scattering matrix for the directional coupler can be represented as
Isolation of the directional coupler is,
Coupling can be represented as,
Directivity as
04/10/23 TCE MADURAI 14
Simulated V/s Measured
04/10/23 TCE MADURAI 15
Conclusion…
• Accurate design for quartered directional coupler
• Solved for tight coupling as well as loose coupling..
• Isolation null is achived..
04/10/23 TCE MADURAI 16
Reference………..• 1 M. Dydyk, “Accurate design of microstrip directional couplers withcapacitive
compensation,” in IEEE MTT-S Int. Dig., May 1990, pp.581–584.
• 2 M. Dydyk, “Microstrip directional couplers with ideal performance viasingle-element compensation,” IEEE Trans. Microw. Theory Tech., vol.47, no. 6, pp. 956–964, Jun. 1999.
• 3 S. L. March, “Phase velocity compensation in parallel-coupled microstrip,”in IEEE MTT-S Int. Dig., 1982, pp. 581–584.
• 4 R. Phromloungsri, V. Chamnanphrai, and M. Chongcheawchamnan,“Design high-directivity parallel-coupled lines using quadrupled inductive-compensated technique,” in Asia-Pacific Microw. Conf. Dig.,2006, pp. 1380–1383.
• 5 R. Phromloungsri, M. Chongcheawchamnan, and I. D. Robertson,“Inductively compensated parallel coupled microstrip lines and theirapplications,” IEEE Trans. Microw. Theory Tech., vol. 54, no. 9, pp.3571–3582, Sep. 2006.
• 6 L. Su, T. Itoh, and J. Rivera, “Design of an overlay directional couplerby a full-wave analysis,” in IEEE MTT-S Int. Dig., May 1983, pp.427–429.
• 7 S. Uysal and H. Aghvami, “Synthesis, design, and construction of ultrawidebandnonuniform quadrature directional couplers in inhomogeneousmedia,” IEEE Trans. Microw. Theory Tech., vol. MTT-37, no. 6,pp. 969–976, Jun. 1989.
04/10/23 TCE MADURAI 17
Thank you
Q & A………….