Microwave zero-bias rectifiers are fast devices capable of rectifying RF signals without applied bias, which have applications ranging from RF power detection to THz imaging systems. Here we present gated nanowire field-effect rectifiers (NW-FERs) fabricated with a process compatible with other RF devices on a standard AlGaN-GaN High Electron Mobility Transistor (HEMT) platform as a new potential RF zero-bias diode. Signal rectification relies on the electrostatic modulation of the gated-NW carrier concentration, which is optimized by a judicious NW width design. NW-FERs presented a large curvature (30.1 V􀀀1), close to the theoretical limit (38.7 V􀀀1) for ideal Schottky diodes, and an excellent trade-off between a flat frequency response, up to a few tens of GHz, and a large responsivity (3000 V/W). The compatible fabrication process and the very good results provide a promising high-performance zerobias diode architecture that could be integrated on AlGaN/GaN microwave monolithic integrated circuits (MMICs).