This paper presents a novel substrate integrated waveguide (SIW) filter, based on quarter-mode cavities, which permits to obtain a transmission zero close to the passband. The use of quarter-mode cavities provides a significant size reduction compared to regular SIW cavities, while preserving most of the advantages. The proposed filter comprises four side-coupled cavities, and the use of cross-coupling permits to introduce the transmission zero. The cross-coupling is due to thin metal strip outside the cavities, and it can be easily controlled to locate the transmission zero at the desired frequency. A four-pole filter operating at frequency of 4 GHz, with a transmission zero very close to the passband, was fabricated and measured. The proposed filter has a footprint of 41x28.5 mm(2), corresponding to 0.55 lambda(0)x0.38 lambda(0), where lambda(0) is the wavelength in vacuum at 4 GHz
Novel compact quasi-elliptic SIW filter based on quarter-mode cavities
TOMASSONI, Cristiano;
2016
Abstract
This paper presents a novel substrate integrated waveguide (SIW) filter, based on quarter-mode cavities, which permits to obtain a transmission zero close to the passband. The use of quarter-mode cavities provides a significant size reduction compared to regular SIW cavities, while preserving most of the advantages. The proposed filter comprises four side-coupled cavities, and the use of cross-coupling permits to introduce the transmission zero. The cross-coupling is due to thin metal strip outside the cavities, and it can be easily controlled to locate the transmission zero at the desired frequency. A four-pole filter operating at frequency of 4 GHz, with a transmission zero very close to the passband, was fabricated and measured. The proposed filter has a footprint of 41x28.5 mm(2), corresponding to 0.55 lambda(0)x0.38 lambda(0), where lambda(0) is the wavelength in vacuum at 4 GHzI documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
