| 257 / | HD | ACTIVE SOLID-STATE DEVICES (E.G., TRANSISTORS, SOLID-STATE DIODES) |
| 213 | DF | FIELD EFFECT DEVICE {6} |
| 215 | DF | .~ Charge transfer device {11} |
| 245 | DF | .~.~ Structure for applying electric field into device (e.g., resistive electrode, acoustic traveling wave in channel) {2} |
| 246 | DF | .~.~.~ Phase structure (e.g., doping variations to provide asymmetry for 2-phase operation; more than four phases or "electrode per bit") {2} |
| 247 | | .~.~.~.~ Uniphase or virtual phase structure |