V-BAND CMOS BANDPASS FILTER WITH TWO ENHANCED FINITE TRANSMISSION ZEROS

摘要

In this article, we demonstrate a miniature low-insertionloss V-band bandpass filter with two finite transmission zeros by standard 0.13-μm CMOS technology. The proposed filter architecture has the following feature: the low-frequency transmission-zero and the high-frequency transmission-zero can be tuned by the series-feedback capacitor Cs and the parallel-feedback capacitor Cp, respectively. Parallel LC circuits (i.e., C_(12) in parallel with LC_1-C_(11)-LC_2 and C_(22) in parallel with LC_3-C_(21)-LC_4) are used for implementing C_1 and C_2 to improve the roll-off characteristic at high frequency and the depth of the upper notch. Besides, low-insertion-loss was achieved by adopting thick microstrip-line (MSL) with optimized ground-plane pattern as the needed inductors to minimize both the metal loss and the substrate loss. Over the frequency range of 49.5-82.5 GHz, the filter achieved insertion-loss (1/S_(21)) lower than 3 dB, and input return loss (S_(11)) and output return loss (S_(22)) better than -10 dB. The minimum insertion-loss was 1.87 dB at 66.5 GHz, a state-of-the-art result for a V-band CMOS bandpass filter. The chip area was only 0.466 × 0.307 (mm)~2, i.e., 0.143 (mm)~2, excluding the test pads.