A quasi-elliptic response triple-mode SIW bandpass filter with controllable transmission zeros

Abstract

This letter reports a novel quasi-elliptic bandpass filter (BPF) using a new triple-mode circle-shaped substrate integrated waveguide (SIW) cavity. The triple-mode SIW cavity is achieved by a dual-mode circle-shaped SIW cavity with a floating capacitive-loaded metallic patch. The resonance of one higher-order mode is independently shifted to that of dual modes to form a three-pole passband. Three finite transmission zeros (FTZs) can be produced, and two of them can be controlled well by the angle between two feeding lines. For the demonstration, a prototype filter was designed, fabricated and measured. Good agreement between measured results and simulated results is observed. The proposed triple-mode SIW filter has the merits of compact size, high selectivity and controllable bandwidth as well as FTZs.

Multi passband filter with one-twelfth mode miniaturized based on substrate integrated waveguide

“…In recent years, the substrate integrated waveguide (SIW) has attracted people's attention due to its high-quality factor, high-power, low-loss, low-cost, easy fabrication and easy integration with planar integrated circuit [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20]. The miniaturization and multi-passband SIW filters have gradually become research hot-spot [21,22,23,24,25,26].…”

Compact bandpass filter based on single isosceles right triangular substrate integrated waveguide cavity and modified complementary compact microstrip resonant cell

“…Its most common applications are filter design [8][9][10][11] and antenna design [12][13][14][15]. Different shapes of SIW cavities have been studied, such as rectangular [16][17][18], circular [19][20][21], and triangular [22][23][24]. Compared with rectangular and circular SIW cavities, triangular SIW cavities not only have similar characteristics, but also have more compact size.…”

Bandpass filter with flat passband and transmission zeros using parallel-connected resistor loaded hairpin-shaped resonators

“…Lacking proper candidates for RF BPFs with flat passband and sharp rejection performance is a problem for wireless systems, especially at higher operating frequencies. Although substrate integrated waveguide (SIW) filters [8,9] are also good performance, the area of a resonator using SIW tends to be larger than a planar type.…”