Towards miniaturization: Reflectionless filter with sharp roll-off characterization based on through-silicon via

-This paper presents a through-silicon via (TSV)-based reflectionless filter with an optimized pseudo-elliptic frequency response. Specifically, the introduction of a resonant branch in the even-mode circuit enhances the roll-off sharpness, resulting in a rectangular coefficient of 1.065 at 20 dB attenuation level. Utilizing odd-even mode synthesis and tuning of the even-mode reflection coefficient, the filter achieves reflection suppression exceeding 19.6 dB across the entire DC-30 GHz bandwidth, thereby ensuring reflectionless performance in both the passband and stopband. Simultaneously, the out-of-band rejection exceeds 14.3 dB while maintaining a passband insertion loss of less than 1 dB, indicating effective signal suppression. Furthermore, through TSV integration, the filter achieves a highly compact footprint of 0.476 × 0.422 mm².