Du Z.,Laboratory of MMIC |
Zhu M.,Laboratory of MMIC |
Zhang H.,Laboratory of MMIC |
Yang H.,Laboratory of MMIC
Guti Dianzixue Yanjiu Yu Jinzhan/Research and Progress of Solid State Electronics | Year: 2012
A second order filter with a pair of poles was used as prototype. ∏-T network equivalent transformation was used for inductor network to reduce impedance thereby reducing the area occupied. T-shape inductor network can be easily realized on one layer using LTCC technology. The transformation of inductor network simplified filter structure. T-stubs were also introduced to improve upper stop band characteristic, hardly affecting on band pass characteristic. The filter has bandwidth of 1 GHz, center frequency at 7.65 GHz, size of 4 mm×3 mm×0.6 mm. The filter was mounted on PCB to be tested, the total insertion loss of microstrip, SMA connector and filter was less than 1.8 dB.