摘要 |
A duplexing filter 10 suitable for use in a mobile communication system. The filter 10 has a core of dielectric material 12 with several through holes 30 that define resonators 25. The core 12 has metallized surfaces 16, 18, 20, 22 and 24 except for the top surface 14. Several metallized resonator pads 60 surround each of the through holes 30 on the top surface 14. A metallized serpentine region 61, 62 extends from one or more of the resonator pads 60 toward a side surface 18 of the core 12. The metallized serpentine region 61, 62 causes attenuation of a third harmonic frequency.
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