Compact wideband CMOS lumped-element Wilkinson power divider with asymmetric negative capacitance circuit

The authors developed a wideband on-chip Wilkinson power divider (WPD) using lumped-element transmission lines (LE TLs) with 2-port negative capacitance (NCAP) circuits that provide the phase response with a positive slope and broadband port impedance. The bandwidth of the WPD was increased using the broadband quarter-wavelength ( λ /4) LE TLs with port-matched NCAP circuits. The WPD was implemented in the Global Foundry 8SF 130-nm RF CMOS IC technology. The size of the core chip is 1100 µm × 400 µm. The S-parameter measurements showed an absolute bandwidth ranging between 0.76 and 1.6 GHz, and a fractional bandwidth of 71.2%. In the frequency range of the bandwidth, the insertion loss was 0.4–3.4 dB, with the isolation between the two output ports was >18 dB, and the noise figures were 11–12 dB. The input-referred 1-dB gain compression point at the frequency of 1 GHz was ‒6 dBm.