Outline  Indent Level  
Color  Curly Brackets (indicating CPC extensions to IPC) References Date Revised  
CPC  COOPERATIVE PATENT CLASSIFICATION 
GENERATION OF OSCILLATIONS, DIRECTLY OR BY FREQUENCYCHANGING, BY CIRCUITS EMPLOYING ACTIVE ELEMENTS WHICH OPERATE IN A NONSWITCHING MANNER ; GENERATION OF NOISE BY SUCH CIRCUITS ( measuring, testing G01R ; generators adapted for electrophonic musical instruments G10H ; Speech synthesis G10L ; masers, lasers H01S ; dynamoelectric machines H02K ; power inverter circuits H02M ; by using pulse techniques H03K ; automatic control of generators H03L ; starting, synchronisation or stabilisation of generators where the type of generator is irrelevant or unspecified H03L ; generation of oscillations in plasma H05H ) 
Details 
Generation of oscillations using amplifier with regenerative feedback from output to input ( H03B 9/00 , H03B 15/00 take precedence ) 
H03B 5/02  .  Details 
. .  Modifications of generator to compensate for variations in physical values, e.g. power supply, load, temperature 
H03B 5/06  . .  Modifications of generator to ensure starting of oscillations 
H03B 5/08  .  with frequencydetermining element comprising lumped inductance and capacitance 
. .  active element in amplifier being vacuum tube ( H03B 5/14 takes precedence ) 
. .  active element in amplifier being semiconductor device ( H03B 5/14 takes precedence ) WARNING 

. . .  { the amplifier being a single transistor } 
. . .  { using multiple transistors for amplification } 
. . . .  { the amplifier having two current paths operating in a differential manner and a current source or degeneration circuit in common to both paths e.g. a longtailed pair. ( H03B 5/1215 takes precedence ) } 
. . . .  { the amplifier comprising a pair of transistors, wherein an output terminal of each being connected to an input terminal of the other, e.g. a cross coupled pair } 
. . . . .  { the current source or degeneration circuit being in common to both transistors of the pair, e.g. a crosscoupled longtailed pair } 
. . . .  { the generator being of the balanced type } 
. . . .  { the amplifier comprising multiple amplification stages connected in cascade } 
. . . .  { the generator comprising multiple amplifiers connected in parallel } 
. . .  { the amplifier comprising one or more field effect transistors } 
. . .  { the amplifier comprising one or more bipolar transistors } 
. . .  { and comprising means for varying the output amplitude of the generator ( H03B 5/1278 takes precedence ) } 
. . .  { comprising means for varying the frequency of the generator } 
H03B 5/124  . . . .  { the means comprising a voltage dependent capacitance } 
H03B 5/1243  . . . . .  { the means comprising voltage variable capacitance diodes } 
H03B 5/1246  . . . . .  { the means comprising transistors used to provide a variable capacitance } 
H03B 5/1256  . . . .  { the means comprising a variable inductance } 
H03B 5/1262  . . . .  { the means comprising switched elements } 
. . . .  { the frequency being controlled by a control current i.e. current controlled oscillators } 
. . . .  { having further means for varying a parameter in dependence on the frequency } 
H03B 5/1278  . . . . .  { the parameter being an amplitude of a signal, e.g. maintaining a constant output amplitude over the frequency range } 
H03B 5/1281  . . . . .  { the parameter being the amount of feedback } 
H03B 5/1284  . . . . .  { the parameter being another frequency, e.g. a harmonic of the oscillating frequency } 
H03B 5/1287  . . . . .  { the parameter being a quality factor, e.g. Q factor of the frequency determining element } 
H03B 5/129  . . . . .  { the parameter being a bias voltage or a power supply } 
. . . .  { having means for achieving a desired tuning characteristic e.g. linearising the frequency characteristic across the tuning voltage range } 
. . .  { the feedback circuit comprising a transformer } 
H03B 5/14  . .  frequencydetermining element connected via bridge circuit to closed ring around which signal is transmitted 
H03B 5/18  .  with frequencydetermining element comprising distributed inductance and capacitance 
H03B 5/1805  . .  { the frequencydetermining element being a coaxial resonator } 
. . .  { the active element in the amplifier being a vacuum tube ( see provisionally also H03B 5/1835 ) } 
. .  { the frequencydetermining element being a cavity resonator } 
H03B 5/1823  . . .  { the active element in the amplifier being a semiconductor device } 
H03B 5/1835  . . .  { the active element in the amplifier being a vacuum tube } 
. .  { the frequencydetermining element being a strip line resonator ( H03B 5/1805 , H03B 5/1817 , H03B 5/1864 and H03B 5/1882 take precedence ) } 
. . .  { the active element in the amplifier being a semiconductor device } 
H03B 5/1858  . . .  { the active element in the amplifier being a vacuum tube ( see provisionally also H03B 5/1835 ) } 
H03B 5/1864  . .  { the frequencydetermining element being a dielectric resonator } 
H03B 5/1882  . .  { the frequencydetermining element being a magneticfield sensitive resonator, e.g. a Yttrium Iron Garnet or a magnetostatic surface wave resonator } 
H03B 5/20  .  with frequencydetermining element comprising resistance and either capacitance or inductance, e.g. phaseshift oscillator 
. .  active element in amplifier being vacuum tube ( H03B 5/26 takes precedence ) 
. .  active element in amplifier being semiconductor device ( H03B 5/26 takes precedence ) 
H03B 5/30  .  with frequencydetermining element being electromechanical resonator 
. .  being a piezoelectric resonator ( selection of piezoelectric material H01L 41/00 ) 
. . .  { the resonator having more than two terminals ( H03B 5/326 takes precedence ) } 
H03B 5/326  . . .  { the resonator being an acoustic wave device, e.g. SAW or BAW device } 
. . .  active element in amplifier being vacuum tube ( H03B 5/38 takes precedence ) 
. . .  active element in amplifier being semiconductor device ( { H03B 5/323 , H03B 5/326 } , H03B 5/38 take precedence ) 
. . . .  { the amplifier being a single transistor ( H03B 5/364 to H03B 5/368 take precedence ) } 
. . . .  { the amplifier comprising field effect transistors ( H03B 5/366 takes precedence ) } 
H03B 5/366  . . . .  { and comprising means for varying the frequency by a variable voltage or current } 
H03B 5/38  . . .  frequencydetermining element being connected via bridge circuit to closed ring around which signal is transmitted 
. .  being a magnetostrictive resonator ( H03B 5/42 takes precedence; selection of magnetostrictive material { H01F 1/00 } ; H01L 41/00 ) 
H03B 5/42  . .  frequencydetermining element connected via bridge circuit to closed ring around which signal is transmitted 
Generation of oscillations using active element having a negative resistance between two of its electrodes ( H03B 9/00 takes precedence ) 
H03B 7/02  .  with frequencydetermining element comprising lumped inductance and capacitance 
H03B 7/04  . .  active element being vacuum tube 
. .  active element being semiconductor device 
H03B 7/10  . .  active element being gasdischarge or arcdischarge tube 
H03B 7/12  .  with frequencydetermining element comprising distributed inductance and capacitance 
H03B 9/01  .  using discharge tubes 
. .  using a retardingfield tube ( using klystrons H03B 9/04 ) 
H03B 9/04  . .  using a klystron 
H03B 9/08  . .  using a travellingwave tube 
H03B 9/10  . .  using a magnetron 
.  using solid state devices, e.g. Gunneffect devices 
H03B 2009/123  . .  { using Gunn diodes } 
H03B 2009/126  . .  { using impact ionization avalanche transit time (IMPATT) diodes } 
H03B 9/14  . .  and elements comprising distributed inductance and capacitance 
H03B 9/141  . . .  { and comprising a voltage sensitive element, e.g. varactor } 
H03B 9/142  . . .  { and comprising a magnetic field sensitive element, e.g. YIG } 
H03B 9/143  . . .  { using more than one solid state device } 
. . .  { the frequency being determined by a cavity resonator, e.g. a hollow waveguide cavity or a coaxial cavity ( H03B 9/141 to H03B 9/143 , H03B 9/147 , H03B 9/148 take precedence ) } 
. . .  { the frequency being determined by a stripline resonator ( H03B 9/141 to H03B 9/143 , H03B 9/148 take precedence ) } 
. . .  { the frequency being determined by a dielectric resonator ( H03B 9/141 to H03B 9/143 take precedence ) } 
Generation of oscillations using a shockexcited tuned circuit ( with feedback H03B 5/00 ) 
.  excited by spark ( spark gaps therefor H01T 9/00 ) 
H03B 11/04  .  excited by interrupter 
Generation of oscillations using deflection of electron beam in a cathoderay tube 
Generation of oscillations using galvanomagnetic devices, e.g. Halleffect devices, or using superconductivity effects ( galvanomagnetic devices per se H01L 43/00 ) 
H03B 15/003  .  { using superconductivity effects ( devices using superconductivity H01L 39/00 ) } 
H03B 15/006  .  { using spin transfer effects or giant magnetoresistance } 
Generation of oscillations using radiation source and detector, e.g. with interposed variable obturator 
Generation of oscillations by nonregenerative frequency multiplication or division of a signal from a separate source ( transference of modulation from one carrier to another H03D 7/00 ) 
H03B 19/03  .  using nonlinear inductance 
H03B 19/05  .  using nonlinear capacitance, e.g. varactor diodes 
H03B 19/06  .  by means of discharge device or semiconductor device with more than two electrodes 
H03B 19/16  .  using uncontrolled rectifying devices, e.g. rectifying diodes or Schottky diodes 
Generation of oscillations by combining unmodulated signals of different frequencies ( H03B 19/00 takes precedence; frequency changing circuits in general H03D ) 
.  by beating unmodulated signals of different frequencies 
Generation of oscillations periodically swept over a predetermined frequency range ( anglemodulating circuits in general H03C 3/00 ) 
Simultaneous generation by a freerunning oscillator of oscillations having different frequencies 
Generation of oscillations providing a plurality of outputs of the same frequency but differing in phase, other than merely two antiphase outputs 
Generation of oscillations by methods not covered by groups H03B 5/00 to H03B 27/00 , including modification of the waveform to produce sinusoidal oscillations ( analogue function generators for performing computing operations G06G 7/26 ; use of transformers for conversion of waveform in acac converters H02M 5/18 ) 
Generation of noise currents and voltages { ( gasfilled discharge tubes with solid cathode specially adapted as noise generators H01J 17/005 ) } 
Indexing scheme relating to details of oscillators covered by H03B 
H03B 2200/0002  .  Types of oscillators 
H03B 2200/0004  . .  Butler oscillator 
H03B 2200/0006  . .  Clapp oscillator 
H03B 2200/0008  . .  Colpitts oscillator 
H03B 2200/001  . .  Hartley oscillator 
H03B 2200/0012  . .  Pierce oscillator 
H03B 2200/0014  .  Structural aspects of oscillators 
H03B 2200/0016  . .  including a ring, disk or loop shaped resonator 
H03B 2200/0018  . .  relating to the cutting angle of a crystal, e.g. AT cut quartz 
H03B 2200/002  . .  making use of ceramic material 
H03B 2200/0022  . .  characterised by the substrate, e.g. material 
H03B 2200/0024  . .  including parallel striplines 
H03B 2200/0026  . .  relating to the pins of integrated circuits 
H03B 2200/0028  . .  based on a monolithic microwave integrated circuit (MMIC) 
H03B 2200/003  .  Circuit elements of oscillators 
H03B 2200/0032  . .  including a device with a Schottky junction 
H03B 2200/0034  . .  including a buffer amplifier 
H03B 2200/0036  . .  including an emitter or source coupled transistor pair or a long tail pair 
H03B 2200/0038  . .  including a current mirror 
H03B 2200/004  . .  including a variable capacitance, e.g. a varicap, a varactor or a variable capacitance of a diode or transistor 
H03B 2200/0044  . .  including optical elements e.g. optical injection locking 
H03B 2200/0046  . .  including measures to switch the gain of an amplifier 
H03B 2200/0048  . .  including measures to switch the frequency band, e.g. by harmonic selection 
H03B 2200/005  . .  including measures to switch a capacitor 
H03B 2200/0052  . .  including measures to switch the feedback circuit 
H03B 2200/0054  . .  including measures to switch a filter, e.g. for frequency tuning or for harmonic selection 
H03B 2200/0056  . .  including a diode used for switching 
H03B 2200/0058  . .  with particular transconductance characteristics, e.g. an operational transconductance amplifier 
H03B 2200/006  .  Functional aspects of oscillators 
H03B 2200/0062  . .  Bias and operating point 
H03B 2200/0064  . .  Pulse width, duty cycle or on/off ratio 
H03B 2200/0066  . .  Amplitude or AM detection 
H03B 2200/0068  . .  Frequency or FM detection 
H03B 2200/007  . .  Generation of oscillations based on harmonic frequencies, e.g. overtone oscillators 
H03B 2200/0072  . .  Frequency hopping and enabling of rapid frequency changes 
H03B 2200/0074  . .  Locking of an oscillator by injecting an input signal directly into the oscillator 
H03B 2200/0076  . .  Power combination of several oscillators oscillating at the same frequency 
H03B 2200/0078  . .  generating or using signals in quadrature 
H03B 2200/008  . .  making use of a reference frequency 
H03B 2200/0082  . .  Lowering the supply voltage and saving power 
H03B 2200/0084  . .  dedicated to Terahertz frequencies 
H03B 2200/0086  . .  relating to the Q factor or damping of the resonant circuit 
H03B 2200/0088  . .  Reduction of noise 
H03B 2200/0092  . .  Measures to linearise or reduce distortion of oscillator characteristics 
. .  Measures to ensure starting of oscillations 
H03B 2200/0096  . .  Measures to ensure stopping of oscillations 
H03B 2200/0098  . .  having a balanced output signal 
H03B 2201/00  Aspects of oscillators relating to varying the frequency of the oscillations 
H03B 2201/01  .  Varying the frequency of the oscillations by manual means 
H03B 2201/011  . .  the means being an element with a variable capacitance 
H03B 2201/012  . .  the means being an element with a variable inductance 
H03B 2201/014  . .  the means being associated with an element comprising distributed inductances and capacitances 
H03B 2201/015  . . .  the element being a cavity 
H03B 2201/017  . . .  the element being a dielectric resonator 
H03B 2201/018  . .  the means being a manual switch 
H03B 2201/02  .  Varying the frequency of the oscillations by electronic means 
H03B 2201/0208  . .  the means being an element with a variable capacitance, e.g. capacitance diode 
H03B 2201/0216  . .  the means being an element with a variable inductance 
H03B 2201/0225  . .  the means being associated with an element comprising distributed inductances and capacitances 
H03B 2201/0233  . . .  the element being a cavity 
H03B 2201/0241  . . .  the element being a magnetically variable element, e.g. an Yttrium Iron Garnet 
H03B 2201/025  . .  the means being an electronic switch for switching in or out oscillator elements 
H03B 2201/0258  . . .  the means comprising a diode 
H03B 2201/0266  . . .  the means comprising a transistor 
H03B 2201/0275  . .  the means delivering several selected voltages or currents 
H03B 2201/03  .  Varying beside the frequency also another parameter of the oscillator in dependence on the frequency 
H03B 2201/031  . .  the parameter being the amplitude of a signal, e.g. maintaining a constant output amplitude over the frequency range 
H03B 2201/033  . .  the parameter being the amount of feedback 
H03B 2201/035  . .  the parameter being another frequency, e.g. a harmonic of the oscillating frequency 
H03B 2201/036  . .  the parameter being the quality factor of a resonator 
H03B 2201/038  . .  the parameter being a bias voltage or a power supply 
H03B 2202/00  Aspects of oscillators relating to reduction of undesired oscillations 
H03B 2202/01  .  Reduction of undesired oscillations originated from distortion in one of the circuit elements of the oscillator 
H03B 2202/012  . .  the circuit element being the active device 
H03B 2202/015  . .  the circuit element being a limiter 
H03B 2202/017  . .  the circuit element being a frequency determining element 
H03B 2202/02  .  Reduction of undesired oscillations originated from natural noise of the circuit elements of the oscillator 
H03B 2202/022  . .  the noise being essentially white noise, i.e. frequency independent noise 
H03B 2202/025  . .  the noise being coloured noise, i.e. frequency dependent noise 
H03B 2202/03  .  Reduction of undesired oscillations originated from internal parasitic couplings, i.e. parasitic couplings within the oscillator itself 
H03B 2202/04  .  Reduction of undesired oscillations originated from outside noise or interferences, e.g. from parasitic couplings with circuit elements outside the oscillator 
H03B 2202/042  . .  the circuit element belonging to the power supply 
H03B 2202/044  . .  the circuit element belonging to transmitter circuitry 
H03B 2202/046  . .  the circuit element belonging to receiver circuitry 
H03B 2202/048  . .  the circuit element being a frequency divider 
H03B 2202/05  .  Reduction of undesired oscillations through filtering or through special resonator characteristics 
H03B 2202/06  .  Reduction of undesired oscillations through modification of a bias voltage, e.g. selecting the operation point of an active device 
H03B 2202/07  .  Reduction of undesired oscillations through a cancelling of the undesired oscillation 
H03B 2202/073  . .  by modifying the internal feedback of the oscillator 
H03B 2202/076  . .  by using a feedback loop external to the oscillator, e.g. the socalled noise degeneration 
H03B 2202/08  .  Reduction of undesired oscillations originated from the oscillator in circuit elements external to the oscillator by means associated with the oscillator 
H03B 2202/082  . .  by avoiding coupling between these circuit elements 
H03B 2202/084  . . .  through shielding 
H03B 2202/086  . . .  through a frequency dependent coupling, e.g. which attenuates a certain frequency range 
H03B 2202/088  . .  by compensating through additional couplings with these circuit elements 