A Millimeter-Wave Substrate Integrated Waveguide Filter Based on TSV Technology

Abstract

This paper presents a Ka-band substrate integrated waveguide (SIW) band-pass filter based on through silicon via (TSV) technology. A tapered coupling slot transition structure is adopted to achieve a smooth transition from ground coplanar waveguide (GCPW) to SIW within a wide frequency band of 20~42GHz. The measured in-band insertion loss of the transition structure is -1.23 dB. Three resonant cavities are added to achieve third-order filtering. Magnetic coupling is achieved by opening windows at the positions of maximum magnetic field intensity between adjacent resonant cavities. Adjusting the window size can alter the coupling coefficient between the cavities, thus making the frequencies of the corresponding resonant points approach or move away from each other. The measured insertion loss of the filter is -2.5 dB at the center frequency of 28.65 GHz with a return loss below -20 dB, and the relative bandwidth is 12.2%. The simulation and measured curves are highly consistent.