IJCST Vol. 2, Issue 1, March 2011
ISSN : 2229-4333(Print) | ISSN : 0976-8491(Online)
Design and Simulation of Magic Tee and Ring Hybrid
Coupler using Ansoft HFSS
Parul Dawar
Dept. of ECE, Guru Tegh Bahadur Institute of Technology, Rajouri Garden,New Delhi, India
Abstract
HFSS is a high-performance full-wave electromagnetic (EM) field
simulator for arbitrary 3D volumetric passive device modeling.It
employs the Finite Element Method (FEM), adaptive meshing,
and brilliant graphics. This paper reports for Magic Tee that a
signal incident on the difference port splits equally between
ports 2 and 3, but the resulting signals are 180 degrees out
of phase.Also, Ring Hybrid junction is a four-port network with
a 180 degree phase shift between two output ports but it can
also be operated so that output ports are in phase. Both the
structures are first designed using HFSS and then simulated.
Keywords
Microwave, HFSS, Microstrip couplers, Active circuits, Power
dividers
I. Introduction
Ansoft HFSS is the tool of choice for high-productivity research.
It uses “Finite Element Method” which involves subdividing
a large problem into individually simple constituent units
which are each soluble via direct analytical methods, then
reassembling the solution for the entire problem space as a
matrix of simultaneous equations as ahown in Fig. 1.
Fig. 2: Constructional details of Magic Tee
Fig. 3: Constructional details of Ring Hybrid Coupler
B. Principle of operation
Fig. 1 : Procedure to simulate devices in HFSS.
II. Designing
A. Construction
Let us design Magic Tee and Ring hybrid coupler as shown in
Fig. and Fig. respectively.
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1. A magic tee is a four-port, 180 degree hybrid splitter, realized
in waveguide as shown in Fig. Like all of the coupler and splitter
structures, the magic tee can be used as a power combiner, or
a divider. It is ideally lossless, so that all power into one port
can be assumed to exit the remaining ports. Port 1 is the (sum)
port, and is sometimes called the
H-plane port, and sometimes called the P-port for “parallel”.
A signal incident on port 1 equally splits between ports 2 and
3, and the resulting signals are in phase. Ports 2 and 3 are
sometimes called the co-linear ports, because they are the only
two that are in line with each other. Port 4 is the (difference
or delta) port, and is sometimes called the E-plane port, or
the S-port for “series”. A signal incident on the difference port
splits equally between ports 2 and 3, but the resulting signals
are 180 degrees out of phase.
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Fig. 4: Magic Tee
ISSN : 2229-4333(Print) | ISSN : 0976-8491(Online)
Fig. 6:For odd mode excitation
2. Ring Hybrid junction is a four-port network with a 180
degree phase shift between two output ports but it can also
be operated so that output ports are in phase. The 180 degree
ring hybrid can be constructed in several forms such as planar
form or other forms like wave guide forms.
Fig. 5: For even-mode excitation
Now consider a unity amplitude wave incident at port 4
(difference port),as in Fig.of the ring hybrid junction. The two
wave components on the ring will arrive in phase at ports and
3, with a net phase difference of 180 degree between these
ports. The two wave components will be 180 degree out of
phase at port1.
Fig. 7 : Top arm
Create Wave Port Excitation 1
Picking the port face:
Select the menu item Edit > Select > Faces
Graphically select the top face of the arm at Z=75mm
To assign wave port excitation as in Fig.
Select the menu item HFSS > Excitations > Assign > Wave
Port
Wave Port : General
Name: p1
Click the Next button
Wave Port : Modes
Click the Next button
Wave Port : Post Processing
Click the Finish button
C. Steps of Construction
1. Magic Tee
Create Top Arm
Select the menu item Draw > Box
Using the coordinate entry fields, enter the box position X: -25.0
25.0, Y: -10.0 10.0, Z: 0.0 0.0, Press the Enter key
Using the coordinate entry fields, enter the opposite corner of
the base rectangle:
dX: 50.0 50.0, dY: 20.0 20.0, dZ: 75.0, as in Fig.
First consider a unit amplitude wave incident at port 1, as in
Fig. the sum port, of the ring hybrid. at the ring junction this
unit wave will divide into two components, which both arrive
in phase at ports 2 and 3, and 180 degree out of phase at
port 4. Using the even-odd mode analysis technique we can
decompose this case into a superposition of two simpler circuits
which are considerably easy to analyze.
Fig. 8 : Assign waveport wxcitation
Set Object Selection
1. Select the menu item Edit > Select > Objects
and Create Arm 2 as in Fig. 9 and then 3 and 4 as in Fig.10.
Fig. 9
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Fig. 10
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IJCST Vol. 2, Issue 1, March 2011
ISSN : 2229-4333(Print) | ISSN : 0976-8491(Online)
2. Ring Hybrid Coupler
Set Default Material
To set the default material as shown in Fig.:
Using the 3D Modeler Materials toolbar, choose Select
Select Definition Window:
Click the Add Material button
View/Edit Material Window as in Fig.:
For the Material Name type: My_Sub
For the Value of Relative Permittivity type: 2.33
For the Value of Dielectric Loss Tangent type: 4.29e 4.29e-4
Click the OK button
Using the coordinate entry fields, enter the radius:
dX: 22.345mm/cos(30*pi/180), dY: 0.0 , dZ: 0.0 , Press the
Enter key
4. Using the coordinate entry fields, enter the height: dX: 0.0
, dY: 0.0 , dZ: 2.286 , Press the Enter key Segment Number
Window
Number of Segments: 6
Create Trace
Select the menu item Draw > Rectangle
Using the coordinate entry fields, enter the rectangle
position
X: -0.89154 , Y: 0.0 , Z: 0.0 , Press the Enter key
Using the coordinate entry fields, enter the opposite corner of
the rectangle:
dX: 1.78308 , dY: 22.345 , dZ: 0.0 , as in Fig..
Fig.15, Fig. 16
III. Analysis Result
Fig. 11 :
A. Analysis Setup For Magic Tee
1. Select the menu item HFSS > Analysis Setup > Add Solution
Setup
Solution Setup Window:
Click the General tab: Solution Frequency: 4.0GHz
: Maximum Number of Passes: 5 Maximum Delta S per Pass:
0.02 To add a frequency sweep:
Select the menu item HFSS > Analysis Setup > Add Sweep
Assign the Perfect E boundary and Create Wave Port Excitation
as in Fig. 12
Select Solution Setup: Setup1
Click the OK button
Edit Sweep Window:
Sweep Type: Fast
2. Frequency Setup Type: Linear Count
Start: 3.4GHz Stop: 4.0GHz
Count: 1001
Save Fields: _ Checked 3. Click the OK button Analyze
To start the solution process:
Select the menu item HFSS > Analyze
Fig. 13 : Perfect E boundary and Create Wave Port Excitation
Create the remaining Traces and Wave Ports as in Fig.14 and
inner ring as in Fig. 15 and 16
Fig.17 :Shows the E-field vectors for signals entering the sum
port
Fig.14
Fig. 15
Fig. 16
Create Substrate
Select the menu item Draw > Regular Polyhedron
Using the coordinate entry fields, enter the center position X:
0.0 , Y: 0.0 , Z: -1.143 , Press the Enter key
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IJCST Vol. 2, Issue 1, March 2011
ISSN : 2229-4333(Print) | ISSN : 0976-8491(Online)
The Device is perfectly matched equal power division
PERFECTLY ISOLATED PORT 3.
Fig. 18: how the delta port excites opposing phases in the
CO-linear arms.
The next plot shows the phase of the transmission coefficients
out the CO-linear ports, when driven by the delta port. Note the
180 degree difference
Fig.21 : Fig. shows that there is 180 DEGREES phase difference
between output arms.
References
[1] Minggang Liu; Zhenghe Feng; "Microwave Conference,
2008.,APMC 2008, Page(s): 1 - 4 ,” A novel hybrid planar
SIW magic Tee .”
[2]
Fig.19: phase of the transmission coefficients out the CO-linear
ports
B. Analysis Setup for ring Hybrid Coupler
1. Select the menu item HFSS > Analysis Setup > Add Solution
Setup
Solution Setup Window:
Click the General tab: Solution Frequency: 4.0 GHz
: Maximum Number of Passes: 20 Maximum Delta S: 0.02
Adding a Frequency Sweep To add a frequency sweep:
Select the menu item HFSS > Analysis Setup > Add Sweep
Select Solution Setup: Setup1
Click the OK button
Edit Sweep Window:
Sweep Type: Fast
Frequency Setup Type: Linear Step : Start: 2.0 GHz
Stop: 7.0 GHz
Step: 0.05 GHz
Save Fields: _ Checked 3. Click the OK button
You, L.Z.; Dou, W.B.; "Microwave and Millimeter Wave Technology",
2007. ICMMT ‘07. 2007 , pp. 1 - 4 ,” Design And Optimization of
Planar Waveguide Magic Tee At W-band .”
[3] Beyer, R.; Rosenberg, U.; "Microwave Symposium Digest",
2003 IEEE MTT-S 2003 , pp. 1207 - 1210 Vol. 2 ,” CAD of
magic tee with interior stepped post for high performance
designs.”
[4] Cassivi, Yves; Wu, Ke; Microwave Conference, 2001.
2001 , Ppp. 1 - 4 ,” Magic Tee Junction Based on Hybrid
Architecture of Microstrip Line and Non-Radiative Dielectric
Waveguide .”
[5] Dong Il Kim; Naito, Y.; "Microwave Theory and Techniques,
IEEE Transactions, 1982 , pp. 2040 - 2046”, BroadBand Design of Improved Hybrid-Ring 3-dB Directional
Couplers”.
[6] Sung-Chan Kim; Baek-Seok Ko; Tae-Jong Baek; Byeong-Ok
Lim; An, D.; Dong-Hoon Shin; Jin-Koo Rhee; "Microwave
and Wireless Components Letters", 2005 , pp. 652 - 654
,” Hybrid ring coupler for W-band MMIC applications using
MEMS technology
[7] Chun-Hsiang Chi; Chi-Yang Chang; "Microwave Conference",
2007 , pp. 548 – 551,” A compact wideband 1800 hybrid
ring coupler using a novel interdigital CPS inverter .”
Parul Dawar received her B.Tech degree
in Electronics and Communications from
GPMCOE, GGSIPU, India, in 2005, the
M.Tech degree in Microwave Electronics from
DOES, Delhi University, India, in 2007. She
is currently Assistant Professor in Guru Tegh
Bahadur Institute Of Technology, GGSIPU,
Delhi. Her research interests include Electro
magnetic Field waves, Optical Communications and Microwave
Electronics. She has authored two books titled “Electromagnetic
Field Theory” and “Concepts in Electromagnetic Field Theory”
under KATSON publications. She has attended and published
various papers in National and International Conferences.
Fig.20 : Fig. shows that at design Frequency:
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