1. Fabrication of Tetra-band Filter on the Ceramic Substrate
Reporter : Min-Tsang Yang
Advisor : Chien-Min Cheng
Hung-Chi Yang

2. Topics
Introduction
Design Flowchart
Conclusion

3. 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.
triple-parallel-coupled2.45 and 5.2 GHz
outer-frame structure1.57 GHz
defected ground structure3.5 GHz.

4. The design flowchart Step 1
Use outer-frame structure to Generate 1.57 GHz
Step 6
Use DGS (Defected Ground Structure) to modify 3.5 GHz
Step 2
Use U-shaped resonator structure to generate 2.45 GHz and two zeros
Step 3
Use triple-parallel-coupled microstrip line to generate and 5.2 GHz
Step 4
Combined
Step 5
Tetra-band filters (1.57 / 2.45 / 3.5 / 5.2 GHz)

5. Outer-Frame Structure
The function of this outer-frame are:
Generate a 1.57 GHz filter
Generate two zeros on upper stopband
The first harmonic was fallen on 3.5 GHz

6. U-shaped resonators The function of this U-shaped resonator are:
Generate a 2.45 GHz filter
Two transmission zeros were generated beside the passband (2.45 GHz)

7. Modified triple-parallel-coupled line
The function of this modified PCML are :
Generate a dual-band bandpass filter (2.45/5.2 GHz)
As the distance D increased ,
two zeros generated between two pass bands

8. Combination of Above Three Structures
Combining the U-shaped resonators, Outer-frame structure and Triple-parallel-coupled microstrip line.

9. U-shaped DGS slot The function of this DGS are:
As W increased gradually, the frequency shifted from 4 GHz to 3.5 GHz
This DGS would enhance and modify the first harmonic of 1.57 GHz to an usable WiMax band

10. The final simulated result of tetra-band bandpass filter
Frequency (GHz)
Bandwidth
(MHz / %)
Insertion Loss (dB)
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

11. The merits of this structure were:
Conclusion
The merits of this structure were:
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.

12. 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.

13. Thanks for your attention