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Fabrication of Tetra-band Filter
on the Ceramic Substrate
Reporter : Min-Tsang Yang
Advisor : Chien-Min Cheng
Hung-Chi Yang
Topics
 Introduction
 Design
Flowchart
 Conclusion
Introduction



Tetra-band bandpass filters could be used
on GPS, WiMAX, and WLAN systems
The characteristics of dielectric ceramic
substrates are: r = 27.9 and Qf=33,100
In this research, three basic structures were
adopted to accomplish the filter.
1.
triple-parallel-coupled2.45 and 5.2 GHz
2.
outer-frame structure1.57 GHz
3.
defected ground structure3.5 GHz.
The design flowchart
Step 1
Use outer-frame
structure to Generate
1.57 GHz
Step 4
Combine
d
Step 5
Combine
d
Step 2
Use U-shaped resonator
structure to generate 2.45
GHz and two zeros
Step 3
Use triple-parallelcoupled microstrip line to
generate 2.45 and 5.2
GHz
Step 6
Use DGS (Defected Ground
Structure) to modify 3.5 GHz
Tetra-band filters (1.57 / 2.45 / 3.5 / 5.2 GHz)
Outer-Frame Structure
0
The function of this
outer-frame are:
Magnitude (dB)
Generate a 1.57 GHz
filter
2. Generate two zeros on
upper stopband
3. The first harmonic was
fallen on 3.5 GHz
1.
-10
-20
-30
-40
S11 ---------S21-50
1
2
3
4
Frequency (GHz)
5
6
U-shaped resonators
The function of this Ushaped resonator are:
0
Generate a 2.45 GHz
filter
2. Two transmission zeros
were generated beside
the passband (2.45 GHz)
1.
Magnitude (dB)
-10
-20
-30
-40
S11 ---------S21-
-50
1
2
3
4
5
Frequency (GHz)
6
7
Modified triple-parallel-coupled line
The function of this modified
PCML are :
2.
Magnitude (dB)
Generate a dual-band bandpass
filter (2.45/5.2 GHz)
As the distance D increased ,
two zeros generated between
two pass bands
-10
-20
-30
-40
S11 ---------S21-
-50
1
2
3
4
5
6
Frequency (GHz)
0
S11
-20
Magnitude (dB)
1.
0
S21
-40
-60
S11 ---------S211
2
3
4
5
Frequency (GHz)
6
7
Combination of Above Three Structures
Combining the U-shaped resonators, Outer-frame
structure and Triple-parallel-coupled microstrip line.
0
-10
Magnitude (dB)

-20
-30
-40
-50
S11 ---------S21-60
1
2
3
4
Frequency (GHz)
5
6
U-shaped DGS slot
0
W
A
W
|S21| (dB)
-10
-20
-30
W=0.3mm
W=0.5mm
W=0.7mm
-40
W=0.3mm ---------W=0.5mm - - - - - W=0.7mm -
-50
3.2
3.6
4
4.4
4.8
Frequency (GHz)
The function of this DGS are:
1. As W increased gradually, the frequency shifted from 4
GHz to 3.5 GHz
2. This DGS would enhance and modify the first harmonic
of 1.57 GHz to an usable WiMax band
The final simulated result of tetraband bandpass filter
Magnitude (dB)
0
-10
Frequency (GHz)
Bandwidth
(MHz / %)
Insertion Loss
(dB)
-20
1.57
130 / 8.3
0.19
2.45
760 / 31
0.18
3.5
380 / 10.8
0.24
5.2
750 / 14.1
0.59
-30
-40
-50
S11 ---------S21-60
1
2
3
4
Frequency (GHz)
5
6
Conclusion
The merits of this structure were:
1.
2.
3.
4.
The depth of zeros all over 30 dB.
The stop-band rejection between 2.45 ~ 3.5
GHz was 20.6 dB, and 12.7 dB between 3.5
GHz ~ 5.2 GHz.
The size of the filter was 26.310.5 mm2.
All the other characteristics (bandwidth and
insertion loss) of the four operating frequencies
(1.57/2.45/3.5/5.2 GHz) were usable for the
modern communication.
References
[1] M. Sagawa, M. Makimoto, and S. Yamashita, "Geometrical structures and
fundamental characteristics of microwave stepped-impedance resonators“
IEEE Transactions Microwave Theory and Techniques,45 (1997) 1078.
[2] C.F. Chen,T.Y. Huang,and R.B. Wu,"Design of Dual- and Triple-Passband Filters
Using Alternately Cascaded Multiband Resonators" IEEE Transactions
Microwave Theory and Techniques, 54 (2006) 3550.
[3] C.H. Lee,C.I. Hsu, and H.K. Jhuang, "Design of a New Tri-Band Microstrip
BPF Using Combined Quarter-Wavelength SIRs“IEEE Microwave and
Wireless Components Letters, 16 (2006) 594.
[4] C.Y. Chen, C.Y. Hsu, and H.R. Chuang, "Design of Miniature Planar Dual
-Band Filter Using Dual-Feeding Structures and Embedde Resonators “IEEE
Microwave and Wireless Components Letters, 16 (2006) 669.
[5] C.M. Cheng, Y.C. Chen, C.F. Yang, and C.C. Chan, “Sintering and
compositional effects on the microwave dielectric characteristics of
Mg(Ta1XNbX)2O6 ceramics with 0.25≦x≦0.35” J. Electroceram.
18 (2007) 155.
[6] W.C. Tzou, Y.C. Chen, C.F. Yang, and C.M. Cheng, Mater. Res. Bull.
“Microwave dielectric characteristics of Mg(Ta1XNbX)2O6 ceramics“, 41
(2006)1357.
Thanks for your attention