(under the class definition) Oscillators wherein the oscillator comprises at least two components (1) a two-terminal or four-terminal active element of electrically conductive, semi-conductive, ferromagnetic or ferroelectric material in the solid state, and (2) a frequency determining network. Usually the two-terminal active element constitutes a negative resistance so connected to the frequency determining network that the resulting oscillator is a two-terminal negative resistance oscillator, whereas the four-terminal active element is so connected to the frequency determining network that the resulting oscillator is of the feedback type.
(1) Note. Oscillator system elements recited in the Class 331 definition of an oscillator system occur in a Gunn element with input and output terminals, even though a Gunn Oscillator isn't even an integrated circuit.
(2) Note. If an oscillator system involving an active solid state device or integrated circuit is claimed, nominally or in detail, then it is properly classified in Class 331, whereas if an oscillator system is not claimed or a subcombination thereof which involves an active solid state
device is claimed, and is not elsewhere classifiable, then they are properly classified in Class 257.
SEE OR SEARCH THIS CLASS, SUBCLASS:
52, for plural oscillator systems comprising two or more oscillators of the semi-conductor active element type connected in cascade.
94, for molecularly resonant type oscillator wherein the resonance properties of particles of a gas, liquid or solid are utilized to produce oscillations. 126+, for oscillators wherein the active element thereof comprises a device of the gaseous discharge type.
SEE OR SEARCH CLASS
257, Active Solid-State Devices (e.g., Transistors, Solid-State Diodes), for active solid-state devices, especially
6, 8 for Gunn effect oscillators, and subclasses 446 and 499+ for integrated circuit devices with electrically isolated components.
307, Electrical Transmission or Interconnection Systems,
401+, for miscellaneous systems, not elsewhere classifiable utilizing ferromagnetic or ferroelectric active elements, and subclass 132 for switching systems of the self-sustaining repetitive make and break type, usually employing electromagnetic relays.
310, Electrical Generator or Motor Structure,
301, for the structure of electric generators or motors utilizing the thermal or pyromagnetic properties of a solid, and subclasses 311+ for the structure of electric generators or motors utilizing the piezoelectric properties of a solid.
322, Electricity: Single Generator Systems,
2, for electrical systems utilizing means of the nonmagnetic type for generating electricity.
327, Miscellaneous Active Electrical Nonlinear Devices, Circuits, and Systems, appropriate subclasses for miscellaneous transistor or electron tube nonlinear circuits.
330, Amplifiers, 250+, for linear amplifiers utilizing solid state active elements.
336, Inductor Devices,
155+, for the structure of inductive regulators with no relatively moving parts, e.g., saturable core transformers or inductors.
361, Electricity: Electrical Systems and Devices,
435, for liquid state, electrolytic circuit breaker devices for converting D. C. to pulses.
438, Semiconductor Device Manufacturing: Process, for methods of making semiconductor electrical devices.
