Generation of oscillations in a non-switching manner, i.e. by harmonic oscillators providing sinusoidal signals.

Generation without frequency changing

by means of amplification and feedback; negative resistance

by means of transit-time tubes; electron-beam tubes

by shock-exciting; Hall effect; radiation source and detectors

Generation with frequency changing

by multiplication or division of a signal

by combining unmodulated signals

Particularities of generated oscillations

Swept-over frequency range; multifrequency; multiphase; noise

This subclass covers circuits and methods dedicated to achieve sinusoidal oscillations by analogue means. This is to be distinguished from circuits and methods intended to generate edge shaped periodic signals (pulses, digital clocks) that are to be classified elsewhere (see references below).

This subclass covers generic oscillators that are generally applicable to any application. Oscillators adapted for a specific application or apparatus (e.g. for a specific measurement device or radar system) and which are not generally applicable should generally be classified in the groups for that application.

Details regarding the means for making the frequency variable

Structural details of power oscillators

Reduction of undesired oscillations

This main group is orthogonal to the other groups within H03B, i.e. multiple classification in H03B 1/00 and in H03B 5/00 - H03B 29/00 is made when appropriate.

Oscillators with feedback comprising in particular

Compensation of variations in parameters affecting the output frequency or amplitude of feedback oscillators (such as power supply, load or temperature) as far as a modification of the generator itself is concerned

Starting of feedback oscillators as long as a modification of the generator itself is concerned

US20100102892, J. Arai

Rb(t): Temperature sensing resistor within the oscillator, considered as a "modification of the generator" falling within the scope of H03B 5/04.

US2009261917, M. Taghivand Et al.: temperature compensating varactor receives control signal from outside the oscillator. NOT to be classified in H03B 5/04, but instead in H03L 1/023, because it is not a "modification of the generator" itself.

Oscillators using amplifier with regenerative feedback with frequency-determining element comprising lumped inductance and capacitance and active element in amplifier being vacuum tube.

Oscillators using amplifier with regenerative feedback with frequency-determining element comprising lumped inductance and capacitance and active element in amplifier being semiconductor device. The majority of transistor based LC oscillators are classified here or in the subgroups.

Documents falling under H03B 5/12 should generally receive multiple classifications from the subgroups and all relevant group symbols should be applied. Generally, it is required to apply at least one of the subgroups H03B 5/1203 or H03B 5/1206 to define the amplifier configuration, at least one of the subgroups H03B 5/1228 and H03B 5/1231 to define the transistor types and possibly also one of the subgroups H03B 5/1234 or H03B 5/1237 to define any variable parameters.

Oscillators using an amplifier with regenerative feedback and a frequency-determining element comprising lumped inductance and capacitance, the active element in the amplifier being a single transistor.

The single-transistor-amplifier should be the amplifier that provides the gain in the oscillation loop. Other amplifiers, e.g. connected after the oscillator and outside the loop are not considered when deciding if a single transistor is used. Auxiliary transistors that are provided for a purpose other than amplification, e.g. as a current source or a switch, are also not counted. Hence any oscillator with a single amplification transistor should be classified here. In general further subgroup symbols under H03B 5/12 will also be added in combination with this one.

Example:

WO0211277, Y.M. Yeong

Single transistor 22 used for amplification in the oscillation loop.

US2008309415, T. Aramata

The circuit contains 5 transistors, but two (Tr4 and Tr5) are used for switching and one (Tr1) is a buffer at the output, these are therefore outside of the oscillation loop and not used for providing gain. The remaining two are providing gain, but in separate oscillation loops. This therefore effectively shows two oscillators, each with a single amplification transistor and is classified in H03B 5/1203.

Oscillators using an amplifier with regenerative feedback and a frequency-determining element comprising lumped inductance and capacitance, the active element in the oscillation amplifier using more than one transistor to provide the gain.

Particular configurations of the multiple amplification transistors:

This group and its subgroups are intended to contain oscillators where multiple transistors are used to provide the gain for a single oscillation loop. For example, differential amplifiers, multistage amplifiers, multiple amplifiers connected in parallel and to a common resonator are all to be found here or in subgroups. Other amplifiers, e.g. connected after the oscillator and outside the loop are not considered for determination whether multiple transistors are present. Auxiliary transistors that are provided for a purpose other than amplification, e.g. as a current source or a switch, are also not counted, so an oscillator comprising a single amplification transistor and a further transistor for switching off the oscillator, would NOT be classified here, but instead as a single transistor in H03B 5/1203.

Oscillators using an amplifier with regenerative feedback and a frequency-determining element comprising lumped inductance and capacitance, the active element in the oscillation amplifier for oscillation using more than one transistor and having two current paths conducting a differential current, i.e. being a differential amplifier. A current source or degeneration circuit in common to both paths provides current which is then split between the two current paths.

Example:

US2007182503, J.G. Petrofsky

Q10L and Q10R are a differential pair and Q16 is the common current source of the differential amplifier. C12 and L12 make the resonator. There is no cross coupling between the transistors of the differential pair.

Oscillators using an amplifier with regenerative feedback and a frequency-determining element comprising lumped inductance and capacitance, the active element in the oscillation amplifier for oscillation comprising a pair of cross-coupled transistors.

This group contains any oscillators where the amplifier contains a pair of transistors the output of each one being connected to the input of the other. The normal case is a cross-coupled emitter or source-coupled pair, but other configurations are also possible.

Example:

US2008258827, M. Tsai

LC oscillator comprising a cross-coupled source-coupled pair of transistors.

Oscillators using an amplifier with regenerative feedback and a frequency-determining element comprising lumped inductance and capacitance, the active element in the oscillation amplifier for oscillation comprising a pair of cross-coupled transistors and a current source or degeneration circuit in common to both paths.

Any oscillators where the amplifier contains a pair of transistors the output of each one being connected to the input of the other and further having a common current source (or degeneration circuit). The current source or degeneration circuit in common to both transistors provides current which is then split between the current paths of the two transistors, hence these are LC oscillators using cross coupled differential amplifiers.

Example:

or

both from US2008258827, M. Tsai

Circuits 14 and 26 act as a current source in common to both transistors of the respective cross-coupled pair and building a differential amplifier.

Oscillators using an amplifier with regenerative feedback and a frequency-determining element comprising lumped inductance and capacitance, the active element in the oscillation amplifier comprising multiple transistors and the generator being of the balanced type.

Here a balanced oscillator is not considered to include the differential type with a cross coupled transistor pair. Instead balanced oscillators are considered to include configurations where at least two amplifiers operate with separate oscillation circuits which are however coupled in such a way as to provide a balanced output. Often a single resonant circuit is coupled between both amplifiers.

Example:

US5012205, W.J. Howell

Transistors 12 and 14 build a balanced type oscillator.

WO2004075394, H. Veenstra

Both two-stage emitter follower circuits provide gain to the single resonant circuit, but are coupled at opposite sides of it to provide a balanced output.

US2008129392, J.Y. Lee

Two colpitts type oscillators coupled in a balanced configuration

Oscillators using an amplifier with regenerative feedback and a frequency-determining element comprising lumped inductance and capacitance, the oscillation amplifier comprising multiple stages in cascade.

Any oscillators where the amplifier contains multiple stages in cascade. This is not considered to include the case where a differential pair is cross coupled (which is instead considered to be a single differential stage) .

Example:

EP1753136, Y. ARAYASHIKI

Two amplifier stages 22a and 22b in a single loop.

Oscillators using an amplifier with regenerative feedback and a frequency-determining element comprising lumped inductance and capacitance, the oscillation amplifier comprising multiple amplifier circuits in parallel.

This subgroup contains any oscillators where the amplifier contains multiple amplifier circuits in parallel, i.e. the inputs of each amplifier are connected together, as are the outputs. It also includes circuits where some or all of the parallel amplifier circuits are or can be switched in or out of the circuit, for example to provide multiple gain levels or for startup. It does not include cases where separate amplifiers are connected to different resonant circuits and therefore not in parallel.

Example:

US2009289732, D. MIYASHITA

An amplifier consisting of transistors M3 and M4 can be switched in parallel with M1, M2 to provide different gain levels.

Oscillators using an amplifier with regenerative feedback and a frequency-determining element comprising lumped inductance and capacitance, the active element in the amplifier comprising at least one FET.

The group includes oscillator circuits where the amplifier of the oscillation loop comprises at least one FET. Where the amplifier includes both FET and bipolar transistors, also the classification H03B 5/1231 should be applied. This group is intended to indicate only the type of transistors used in the amplifier of the oscillation loop, but those transistors can be used to provide the gain or for other auxiliary purposes, e.g. for biasing. Hence an amplifier using one transistor type for amplification and another for biasing should receive both group symbols H03B 5/1228 and H03B 5/1231. This class is not applied to classify transistor types used at other places in the circuit, for example buffer circuits at the output and therefore not inside the oscillation loop. It is also not used to distinguish transistor types used in the oscillation loop but not part of the amplifier - for example the type of transistors providing a voltage dependent capacitance are classified in the groups H03B 5/125 and H03B 5/1253.

Oscillators using an amplifier with regenerative feedback and a frequency-determining element comprising lumped inductance and capacitance, the active element in the amplifier comprising at least one bipolar transistor.

The subgroup includes oscillator circuits where the amplifier of the oscillation loop comprises at least one bipolar transistor. Where the amplifier includes both FET and bipolar transistors, also the classification H03B 5/1228 should be applied. This group is intended to indicate only the type of transistors used in the amplifier of the oscillation loop, but those transistors can be used to provide the gain or for other auxiliary purposes, e.g. for biasing. Hence an amplifier using one transistor type for amplification and another for biasing should receive both group symbols H03B 5/1228 and H03B 5/1231. This class is not applied to classify transistor types used at other places in the circuit, for example buffer circuits at the output and therefore not inside the oscillation loop. It is also not used to distinguish transistor types used in the oscillation loop but not part of the amplifier - for example the type of transistors providing a voltage dependent capacitance are classified in the groups H03B 5/125 and H03B 5/1253.

Oscillators using an amplifier with regenerative feedback and a frequency-determining element comprising lumped inductance and capacitance, the active element being a semiconductor device (e.g. a transistor) and further having means providing a variable output amplitude.

Oscillators using an amplifier with regenerative feedback and a frequency-determining element comprising lumped inductance and capacitance, the active element being a semiconductor device (e.g. a transistor) and the frequency being tunable.

Particular aspects of the frequency tuning:

Oscillators using an amplifier with regenerative feedback and a frequency-determining element comprising lumped inductance and capacitance, the active element being a semiconductor device (e.g. a transistor) and the frequency being tuned by a control current.

All types of current controlled oscillators are classified here, regardless of whether the control current is applied to a current dependent inductor or capacitor or whether it is applied elsewhere (e.g. as a bias to an active element) where a frequency tuning is thereby achieved. Additional group symbols should be applied where appropriate, e.g. typically H03B 5/124, H03B 5/1256 or their subgroups.

Oscillators using an amplifier with regenerative feedback and a frequency-determining element comprising lumped inductance and capacitance, the active element being a semiconductor device (e.g. a transistor), the frequency being tuned and additionally having means for achieving a desired tuning characteristic.

Typically the desired tuning characteristic is a linear control voltage to frequency characteristic, but this subgroup covers any measures to obtain any tuning characteristic. For example, stepwise linear functions or higher and subgroupser tuning sensitivity (which amount to a steeper/less steep tuning curve) are also covered.

Oscillators using an amplifier with regenerative feedback and a frequency-determining element comprising lumped inductance and capacitance, the active element being a semiconductor device (e.g. a transistor), the frequency being tuned and another parameter also being varied (continuously or in steps) in dependence on the oscillation frequency.

Typical examples for documents to be classified here or in the subgroups are:

Oscillators using an amplifier with regenerative feedback and a frequency-determining element comprising lumped inductance and capacitance, the active element being a semiconductor device (e.g. a transistor) and further having a transformer in the feedback path.

Oscillators using amplifier with regenerative feedback and frequency-determining element comprising distributed inductance and capacitance and being a coaxial resonator and the active element in the amplifier being a vacuum tube.

Oscillators using amplifier with regenerative feedback and the frequency-determining element being a cavity resonator.

Physical details of cavity resonators that can be regarded as distributed inductances.

Example of an oscillator with cavity resonator:

FR2699346, L. Fourdan

1: cavity

Oscillators using amplifier with regenerative feedback and the frequency-determining element being a strip-line resonator.

Resonators comprising a strip-line and another of the resonator types defined in the other subgroups of H03B 5/18, i.e. coaxial, cavity, dielectric or field sensitive resonators, are classified according to the other resonator, i.e. not in H03B 5/1841.

Oscillators using amplifier with regenerative feedback and the frequency-determining element being a strip-line resonator and the active element in the amplifier being a semiconductor device.

Example:

EP1117177, T. Tanemura

The resonance circuit (8) comprises a microstrip line (10); the active element in the amplifier is a semiconductor device (1).

Oscillators using amplifier with regenerative feedback and the frequency-determining element being a strip-line resonator and the active element in the amplifier being a field-effect device.

Example:

EP1993199, S. El Rair

The resonance circuit comprises microstrip lines (403, 407, 411, 415, ); the semiconductor device in the amplifiers (405, 409, 413) are field effect transistors.

Oscillators using amplifier with regenerative feedback and frequency-determining element comprising resistance and either capacitance or inductance and active element in amplifier being vacuum tube.

Oscillators using amplifier with regenerative feedback and frequency-determining element comprising resistance and either capacitance or inductance and active element in amplifier being semiconductor device.

Example:

US2010231311, S.W. Park

Example of an RC oscillator

Oscillators using amplifier with regenerative feedback and frequency-determining element comprising resistance and either capacitance or inductance and frequency-determining element being part of bridge circuit in closed ring around which signal is transmitted; frequency-determining element being connected via a bridge circuit to such a closed ring. Most commonly these are Wien Bridge type oscillators.

Example:

EP1520339, K. Panzer

RC oscillator in Wien-bridge configuration

Oscillators using amplifier with regenerative feedback with frequency-determining element being a piezoelectric resonator

Oscillators using amplifier with regenerative feedback with frequency-determining element being a piezoelectric resonator having more than two terminals.

Oscillators using amplifier with regenerative feedback with frequency-determining element being a piezoelectric resonator and active element in amplifier being vacuum tube.

Oscillators using amplifier with regenerative feedback with frequency-determining element being a piezoelectric resonator and active element in amplifier being semiconductor device.

Oscillators using amplifier with regenerative feedback with frequency-determining element being a piezoelectric resonator and active element in amplifier being a single transistor.

Example:

US2008174377, T. Makuta et al.,

Oscillator including an electromechanical resonator (2) and a single transistor amplifier (Tr).

Oscillators using amplifier with regenerative feedback with frequency-determining element being a piezoelectric resonator and active element in amplifier comprising field effect transistors.

Example:

EP2341611, S. Ramet

Oscillator including an electromechanical resonator (10) and an amplifier comprising a field effect transistor (MN).

Oscillators using amplifier with regenerative feedback with frequency-determining element being a piezoelectric resonator and active element in amplifier being semiconductor device and comprising voltage variable capacitance diodes for varying the frequency.

Example:

EP2243215; J.-B. David et al

Oscillator including an electromechanical resonator (101) and voltage variable diodes (108, 110) to vary the frequency.

Oscillators using amplifier with regenerative feedback with frequency-determining element being a magnetostrictive resonator.

Oscillators comprising a device with negative differential resistance as active element

Oscillators using active element having a negative resistance between two of its electrodes with frequency-determining element comprising lumped inductance and capacitance and active element being semiconductor device.

Oscillators with negative differential resistance elements such as Gunn diodes in so far as their transit time effect is not relevant.

Oscillators using active element having a negative resistance between two of its electrodes with frequency-determining element comprising lumped inductance and capacitance and active element being a tunnel diode.

Example:

Xiong et al., Sensors and actuators A, 150 (2009), p. 169

Oscillator using a resonant tunnel diode (RTD) as an element with negative differential resistance

Oscillators using active element having a negative resistance between two of its electrodes with frequency-determining element comprising distributed inductance and capacitance and active element being a semiconductor device.

Example:

US5223802, J.F. Harvey

Oscillator with frequency determining element comprising transmission as distributed inductance and a resonant tunnel diode (22) as an active semiconductor device with negative differential resistance.

Oscillators comprising a device with transit-time effects as frequency determining element:

Gunn diodes, in so far as only their negative differential resistance is relevant, not their transit time effect, are classified in H03B 7/06.

Examples:

US2010085126, Y.-W. Lee et al.

Oscillator with metal-insulator device (700)

US2002011604, M. Yagura et al.

Gunn-diode (601) based oscillator

Generation of oscillations using transit-time effects in solid state devices and elements comprising distributed inductance and capacitance, the frequency being determined by a cavity resonator

Spark excited oscillation circuits

Interrupter excited oscillation circuits

EP1873903

Microwave generator including a spark gap (36) between central (12) and external (14) electrode.

Oscillators based on cathode ray tubes with a feedback path.

Example:

GB 126019, J. Bethenod. Electric field applied between two plates 4 to steer the electron beam and oscillate it between the two anodes 5 and 5'.

Oscillators based on galvano-magnetic devices

Oscillators including a radiation source and detector, for example opto-electronic oscillators based on detection of optical signals. The radiation could be in the form of light, but also other radiation types, (e.g. terahertz radiation).

Example:

WO2007143627

Opto-electronic oscillator generating electronic oscillations by detecting an optical signal

Generation of periodic sinusoidal waveforms based on an oscillating input signals and subsequent division or multiplication

Examples:

US2011143689

Generation of a periodic signal (y2) based on a higher frequency signal (y1) followed by configurable division (210) and a configurable delay (220).

Combination of periodic unmodulated signals of different frequencies to form an oscillating signal

Example for H03B 21/00:

US6081696

Generation of a multi-channel oscillation by adding independent signals of various frequencies.

Example:

US7772932

Generation of an oscillation by mixing unmodulated signals of different frequencies ((4/3) RF and (1/3) RF)

Periodic sweeping of oscillation frequency

Examples:

EP2127066

Sweep of oscillation frequency of a radar generator (free running dielectric resonator oscillator, FRDRO) controlled by a complex programmable logic device (CPLD) and a direct digital synthesiser (DDS).

Circuits and methods generating at least two oscillating signals differing in frequency.

Examples:

GB2340681

Generation of three signals differing in frequency at individual outputs (A', A'', C)

US2008169846

Comb generator providing base frequency and harmonics

Oscillators generating polyphase signals, such as quadrature oscillators.

Examples:

US2011148535

Oscillator generating 6 signals of same frequency and 60° phase difference.

EP1764911

Quadrature oscillator

Any types of oscillators which fall within the group definition for H03B, but which do not fall within any of the main groups. Includes combining or filtering non-sinusoidal waves to generate a sinusoid.

Examples:

EP2206231

Summing of square waves to provide an approximation of a sinusoidal waveform

Circuits used to generate random or noise signals e.g. Additive White Gaussian Noise (AWGN) or other noise distributions.

Types of oscillators

Structural aspects of oscillators

Circuit elements of oscillators

Functional aspects of oscillators