A Research of Miniaturized Low-pass Filter Based on LTCC

Due to the low frequency and long wavelength of the filter, miniaturization has become a huge difficulty. The cut-off frequency of low-pass filter is 1000MHz, it belongs to the UHF. To achieve high performance on the basis of miniaturization, it is created by a structure of resonant units by LTCC technology. Using the circuit simulation and 3D simulation software to optimize and simulate, the measured results of the filter match well with the electromagnetic simulation, at the cut-off frequency 1000MHz the insertion loss is 0.54dB, at 1500MHz the stop-band attenuation is better than 25dB and between 2GHz and 5.5 GHz it is better than 35dB, VSWR <= 1.3. Its size of the fabricated filter is only 3.2mmx1.6 mmx0.94mm.