Field-plate structures are disclosed for electrical field management in semiconductor devices. A field-plate semiconductor device comprises a semiconductor substrate, a first ohmic contact and a second ohmic contact disposed over the semiconductor substrate, one or more coupling capacitors, and one or more capacitively-coupled field plates disposed over the semiconductor substrate between the first ohmic contact and the second ohmic contact. Each of the capacitively-coupled field plates is capacitively coupled to the first ohmic contact through one of the coupling capacitors, the coupling capacitor having a first terminal electrically connected to the first ohmic contact and a second terminal electrically connected to the capacitively-coupled field plate.