A 3-D Miniaturized High Selectivity Bandpass Filter in LTCC Technology
- Citation data:
IEEE Microwave and Wireless Components Letters, ISSN: 1531-1309, Vol: 24, Issue: 1, Page: 8-10
- Publication Year:
- Physics and Astronomy; Engineering; Bandpass filter (BPF); Low temperature co-fired ceramic (LTCC); System on package (SoP)
Transmission zeros are used to improve the roll-off factors of filters but as a consequence, the out-of-band rejection decreases. In this work, an LTCC filter design is presented which employs a series inductor (implemented as a via hole) to improve the out-of-band rejection by introducing a third transmission zero. The filter, designed for GPS band (1.57 GHz), has one of the smallest reported foot prints ((0.063×0.048×0.005)λ) and demonstrates the highest roll off factor (16.7 dB/100 MHz) for this band. With only four LTCC layers, the design is cost effective and thus highly suitable for miniaturized, ultra-thin system-on-package applications. © 2001-2012 IEEE.