Millimeter-Wave Wide-Band Bandpass Filter in CMOS Technology Using a Two-Layered Highpass-Type Approach With Embedded Upper Stopband
Zeyu Ge, Lisheng Chen, Roberto Gómez‐García, Xi Zhu
Abstract
An on-chip millimeter-wave (mm-wave) broad-band bandpass filter (BPF) developed in bulk CMOS technology is reported. It is based on a two-layered implementation in which the circuit structure patterned in the top layer exhibits a highpass-type filtering response, whereas an upper stopband is created by the bottom-layer cell when coupled to the top-layer one to obtain a composite overall quasi-elliptic-type wide-band BPF functionality. The locations of the transmission zeros (TZs), which confer sharp-rejection capabilities to the overall frequency response, can be flexibly adjusted with the values of the capacitors that are employed in both layers. A simplified equivalent lumped-element circuit model of the proposed wide-band BPF approach is provided and applied to multi-stage BPF arrangements for higher-selectivity designs. Furthermore, for practical-demonstration purposes, an on-chip passive-integrated single-stage broad-band BPF prototype on silicon with 34.5-GHz center frequency and 61.2% 3-dB relative bandwidth is designed, manufactured, and characterized.