A 68-GHz Loss Compensated Distributed Amplifier Using Frequency Interleaved Technique in 65-nm CMOS Technology

This article presents a frequency interleaved technique (FIT) that can be applied to add resonant peaks in the response of distributed amplifier (DA) for loss compensation and then a frequency-interleaved distributed amplifier (FIDA) that can achieve a high-gain and wide-bandwidth frequency response by summing multiple overlapping distinct-band frequency responses through a distributed configuration. A detailed discussion was introduced to verify the FIDA and a DA was implemented using the FIT. The reported 65-nm CMOS FIDA chip occupies an area of 0.9 x 0.95 mm² and achieves a 17.2 dB small-signal power gain, 2-68 GHz -3-dB bandwidth, gain bandwidth product (GBW) of 478 GHz, and gain ripple of less than 2 dB, while consuming 120 mW under 1.2 V.