Develop Dual-Mode DGS Bandpass Filters Using High Quality Factor Aluminum Oxide Ceramic Substrates
Aluminum Oxide microwave dielectric ceramics exhibit good microwave dielectric characteristics and suitable be used in the microwave devices. In this letter, using screen-printing technique and Ag/Pd paste, a novel dual-mode 2.4 GHz microstrip bandpass filter with U-shaped defected ground structure is screen printed on the Aluminum Oxide (Al2O3, relative dielectric constant=9.8) microwave dielectric ceramic substrate. In addition, a pair of input/output microstrip lines are designed to be 50 Ω and coupled to a λ/4×λ/4 square loop resonator. And in the ground plane, a U-shaped defected ground structure is used toλ excite the degenerate modes, which can be considered as a perturbation element to control the odd-mode frequency and -3 dB bandwidth of the bandpass filter. Finally, the coupling effects between these degenerate modes are presented and detailed investigated.
Wei Pan and Jianghong Gong
C. M. Cheng et al., "Develop Dual-Mode DGS Bandpass Filters Using High Quality Factor Aluminum Oxide Ceramic Substrates", Key Engineering Materials, Vols. 512-515, pp. 1115-1118, 2012