Miniature 1.87‐dB insertion‐loss V‐band CMOS bandpass filter with two enhanced finite transmission zeros

In this article, we demonstrate a miniature low‐insertion‐loss 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 C s and the parallel‐feedback capacitor C p , respectively. Parallel LC circuits (i.e., C 12 in parallel with L C1 ‐ C 11 ‐ L C2 and C 22 in parallel with L C3 ‐ C 21 ‐ L C4 ) 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. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1830–1836, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25302