This paper presents a design methodology to size a transimpedance amplifier for an automotive radar receiver. Based on the Enz-Krummenacher-Vittoz (EKV) MOSFET model, it presents the essential equations to develop a small-signal model featuring a limited number of parameters, which can be exploited to quickly explore the different design optimums of a circuit. Post-layout simulations are presented to validate the model and the methodology. The designed TIA presents a gain of 65 dBΩ, a bandwidth of 80 MHz, an input impedance of 74 Ω and input-referred noise of 50 yA2.Hz−1.