Versatile wideband impedance matching circuit based on current conveyors
The first active impedance matching circuit for RF applications is introduced. It adapts arbitrary output impedances to values between 50 and 250 Ω, from 0 to 5 GHz, and occupies only 0.005 mm2 in 0.35 µm SiGe-BiCMOS. It is vastly superior to traditional passive-element solutions by being: the first flexible matching circuit to adapt any impedance to any desired value; the smallest matching circuit ever; and a rare example of wideband matching. Application to a low-noise amplifier proves the potential of the new circuit.