CMOS 35/70 GHz Dual-Band Bandpass Filter With Five Transmission Zeros Using Compact Stub-loaded Coupled-Line Unit

This paper presents the design and implementation of a millimeter-wave on-chip dual-band bandpass filter (DBBPF) using 0.35 μm standard BiCMOS process. A compact transmission line topology based on stub-loaded coupled line unit is proposed to implement the DBBPF. Sharp-rejection passbands are realized with five transmission zeros (TZ) that are controlled by the impedances of the proposed configuration. Only three impedances are involved in the entire design and the topology is compact and free from the usage via holes and multiple metallization levels. A prototype 35/70 GHz DBBPF is demonstrated and the measured results are found to be in good agreement with the simulation results. Five TZs are seen in both simulation and measurements resulting in sharp roll-off characteristics.