Reliable and $Q$ -Enhanced Floating Active Inductors and Their Application in RF Bandpass Filters

This paper presents three new floating active inductor (FAI)-based bandpass filter (BPF) topologies, namely, the nominal-Q BPF (NQF), Q-enhanced BPF-1 (QF
₁
), and Q-enhanced BPF-2 (QF
₂
). The filters utilize voltage differencing transconductance amplifier (VDTA) as an active building block and are implemented in a 45-nm CMOS process. Negative resistance techniques are used to enhance the quality factor and an addition-based current reference technique reduces the sensitivity of filter's design metrics to process, voltage, and temperature (PVT) variations. The performances of the filters are analyzed in the presence of parasitics and analytical expressions are derived. The proposed filters consume minimal power, possess a high Q and good dynamic range, and are reliable despite being implemented in the nanoscale regime. The NQF/QF
₁
/QF
₂
exhibits a center frequency of 4.36/3.63/3.02 GHz, quality factor of 17.84/54/46.2, the 3-dB bandwidth of 244.4/67.22/65.36 MHz, the dynamic range of 122.49/118.58/119.46 dB, and a 1-dB compression point of -3.06/-5.48/-5.45 dBm. The filter topologies consume 0.552/0.608/0.634 mW from ±1-V supply voltage. The above-mentioned parameters translate into a figure-of-merit FOM
₁
(FOM
₂
) of 125.07 dB-Hz/mW (80.59 dB)/120.74 dB-Hz/mW (81.33 dB)/121.44 dB-Hz/mW (79.81 dB) for NQF/QF
₁
/QF2.