Outline  Indent Level  
Color  Curly Brackets (indicating CPC extensions to IPC)  
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 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  . . . 
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 ) 
. . . 
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 ) 
. . . . 
. . . . 
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 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 ) 
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 