Design of 60GHz millimetre-wave bandpass filter on bulk CMOS

A 60GHz integrated second-order bandpass filter using rectangular open-loop resonators was designed and fabricated on a 0.13m standard CMOS process. The size of the filter is 415.5 × 502.8m2. The designed filter has a pair of transmission zeros at finite frequencies in the stopband, exhibiting good selectivity. The measured filter with the grid ground plane has a flat passband and its 1dB bandwidth is 9GHz (59.5-68.5GHz). The insertion loss is about 2.6dB and the return loss is better than 8.5dB across the passband. The effects of various ground configurations have been studied. The design was optimised with a new slotted ground plane, and its measurement shows a 1dB bandwidth of 9GHz (57-66GHz). The insertion loss is about 1.5dB and the return loss is better than 9.2dB across the passband. The new optimised slotted ground provides better than 1dB and 0.7dB improvement to insertion and return loss, respectively. A very good agreement between the simulation and measurement results has been achieved for frequencies up to 110GHz. Compared with other 60GHz CMOS bandpass filters recently reported in the literature, this 60GHz CMOS bandpass filter has achieved all of low-insertion loss, compact size and good selectivity in one design. The ground optimised design was also implemented as part of fully integrated 0.13m CMOS direct-conversion transmitter. © 2009 The Institution of Engineering and Technology.