This document proposes a method for creating multi-port couplers by mirroring conventional coupler structures. It describes mirroring 90 hybrid couplers to create a four-way coupler and mirroring Saleh power-dividing couplers to create an eight-way coupler. Both structures were simulated in ADS and tested to validate the method. The testing found good agreement between theoretical analysis and measurements, demonstrating the mirrored couplers maintain features like equal power division and stable phase shifting between ports.

1. PAPER SIMULATION USING ADS CAD:
MIRRORED COUPLING STRUCTURES FOR
MICROWAVE
SIGNAL SPLITTING AND COMBINING
Omid Abolghasemi
Dr. Vahid Nayyeri

2. ABSTRACT
•method of creating multi-port couplers by mirroring conventional
coupler structures.
•maintain stable phase shifting between ports, equal power dividing,
and port isolation.
•Example structures: a four-way coupler by mirroring 90 hybrid
couplers and an eight-way coupler by mirroring Saleh power-dividing
couplers were built and tested according to the method discussed.
•good match between theoretical analysis and measurements.
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3. INTRODUCTION
•couplers were designed to meet different system requirements, e.g.,
Wilkinson couplers [1], 90 quadrature couplers [2], rat-race couplers
[3], Lange couplers [4],Saleh’s multi-way dividers [5], and Bagley
polygon couplers[15]–[18]. maintain stable phase shifting between
ports, equal power dividing, and port isolation.
•It is not easy to find new coupler structures, especially those couplers
with multi-ports, equal power division, and stable phase shifting.
•method of creating a new group of coupler structures by mirroring
conventional coupling structures.
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4. I. INTRODUCTION
•A general theoretical S-parameter analysis method is then suggested
for such coupler analysis.
•To validate the method, we derive the S-parameters of a six-port
coupler by mirroring the conventional 90 quadrature couplers, which
is compared with Agilent Technologies’ Advanced Design System
(ADS) (computer-aided design (CAD) software) simulation results.
•In order to validate our design theory, we designed and fabricated a
four-way coupler (by mirroring 90 quadrature couplers) and an eight-
way coupler (by mirroring Saleh’s four-way couplers [5]) according to
the theory discussed. Tested results showed that these couplers
maintain useful features of the original couplers, such as equal power
division, stable phase shifting between output ports, and good
isolation between ports.
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5. II. DESIGN THEORY
Fig. 2. (a) Mirrored structures with a transmission line
between two selected ports, and a passive network
connecting these two ports with all other ports. (b) Using
the transmission line as mirror edge, new structure with
more input/output ports can be created. note: all
impedance used are normalized impedance, and all lines
are 90 in length unless otherwise stated.
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•for the structure of Fig. 2(a), it is
expected that port P1 and P2
remain isolated and input power
will be equally divided between
port P3 to P6;
•for the mirrored structure of Fig.
2(b), it is expected that input
power is equally divided between
port P3, P4, P6, and input port P1
will be isolated with port P2 and
P5.

6. II. DESIGN THEORY
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7. II. DESIGN THEORY FIG. 2(A) ADS
SIMULATION
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8. II. DESIGN THEORY FIG. 2(B) ADS
SIMULATION
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9. III. REALIZATION AND TESTS
Fig. 7. Mirrored couplers optimized for
maximizing working bandwidth.(a)
Mirrored quadrature coupler structure.
(b) Mirrored Saleh coupler structure
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•Built & Simulate Two structures:
the four-way coupler shown in Fig.
7(a) and the eight-way coupler
shown in Fig. 7(b). The commonly
used RO4003C 32 mil 1/4-oz
laminate was selected for these
coupler design and fabrication.

10. III. REALIZATION AND TESTS
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TABLE I
•(top) KEY PARAMETERS OF THE
MIRRORED STRUCTURE OF FIG.
7(a) AFTER OPTIMIZATION.
(bottom) KEY PARAMETERS OF
THE MIRRORED STRUCTURE OF
FIG. 7(b) AFTER OPTIMIZATION
•RO4003C 32 mil 1/4-oz
•obtaining 600-MHz bandwidth
centered at 6.1 GHz

11. III. REALIZATION AND TESTS FIG.
7(A)
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12. III. REALIZATION AND TESTS FIG. 7(A) ADS IDEAL
SIMULATION
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13. III. REALIZATION AND TESTS FIG. 7(A) ADS
REALIZED SIMULATION
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14. III. REALIZATION AND TESTS FIG. 7(A) ADS
REALIZED SIMULATION
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Substrate Definition
•ADS Database
•Rogers RO4000® Series
High Frequency Circuit
Materials Datasheet

15. III. REALIZATION AND TESTS FIG. 7(A) ADS
REALIZED SIMULATION
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Substrate Definition
•Layers Setup

16. III. REALIZATION AND TESTS FIG. 7(A)
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Fig. 10. Back-to-back configurations of the designed four-
way mirrored quadrature coupler and high power. (a) Back-
to-back connection of the four-way mirrored quadrature
coupler. (b) Four-way power combining using the designed
coupler.

17. III. REALIZATION AND TESTS FIG. 7(A)
IMPORT INTO ADS MOMENTUM
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18. III. REALIZATION AND TESTS FIG. 7(A)
SIMULATION USING ADS MOMENTUM
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19. III. REALIZATION AND TESTS FIG. 7(A)
SIMULATION USING ADS MOMENTUM OUTPUTS
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20. III. REALIZATION AND TESTS FIG.
7(B)
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eight-way coupler shown in Fig. 6(b). The commonly used RO4003C 32 mil 1/4-oz
laminate was selected for these coupler design and fabrication.

21. III. REALIZATION AND TESTS FIG.
7(A)
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22. III. REALIZATION AND TESTS FIG. 7(B) ADS IDEAL
SIMULATION
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23. III. REALIZATION AND TESTS FIG. 7(A)
IMPORT INTO ADS MOMENTUM
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24. III. REALIZATION AND TESTS FIG. 7(A)
SIMULATION USING ADS MOMENTUM
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25. III. REALIZATION AND TESTS FIG. 7(A)
SIMULATION USING ADS MOMENTUM OUTPUTS
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26. CONCLUSIONS
1. Shift in Frequency may caused by simulating SMA connectors or
other not mentioned components
2. With the method, it suggests that new coupling structures could be
obtained by mirroring passive structures; and the most important
is these mirrored structures can maintain useful features of the
original structures, such as equal power splitting, stable phase
shifting between output ports, good port matching and isolation,
and more.
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27. REFERENCES:
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