Study of L-band miniature lumped element LTCC band-pass filter

Multilayer LTCC technology enables RF modules to be reduced dramatically by taking advantage of the three dimensional flexibility. Compared to the conventional two dimensional PCB, LTCC allows higher density, smaller size, and lower cost. In this paper, the design of Low-Temperature Co-fired Ceramic (LTCC) multi-layer band pass filter (BPF) for 1080MHz wireless communication system is introduced, which is based on classical design theory of band pass filter and LTCC technology. An experimental BPF has been made and measured. The insertion loss of L-band BPF filter is less than 5.1 dB and 1 dB bandwidth is about 150 MHz at the center frequency 1060 MHz, the stop-band attenuation is more than 30 dB at 780 MHz and 1380 MHz. This filter response is expected to enough for 1080 MHz wireless communication system.