A 77-GHz CMOS on-chip bandpass filter with balanced and unbalanced outputs

This letter presents the design and implementation of a 77-GHz millimeter-wave on-chip bandpass filter with balanced output that was fabricated using a TSMC 0.18-μmstandard CMOS process. The performances of the single-ended and single-ended-to-differential bandpass filters are simulated and measured. The chip size of the designed filter is 0.55×0.7mm². The simulated and measured results of the proposed filter are found to be in good agreement. The filter has a 3-dB bandwidth of about 14 GHz at a center frequency of 77 GHz. The measured insertion loss of the passband is about 6 dB and includes a 3-dB splitting loss; the return loss is less than 10 dB within the passband.