Abstract: A substantially quadratic relationship between the channel current I.sub.DS and the gate voltage V.sub.GS is obtained over a substantial portion of the operating characteristic of a junction field effect transistor by the unique combination of two design features. First, a high-ohmic substrate sub-region is provided adjoining the channel region of the device, and second, the surface-adjoining source region is electrically connected to the underlying substrate. By using these two features, the value of the quantity .beta. is maintained substantially constant over the range of gate-to-source voltages of from zero volts to pinch-off.