| ReturnTo Theme-Group-Choice | Onelevelup |
| 5K052 | Noise elimination | |
| H04B1/10 -1/14;15/00-15/06 | ||
| H04B1/10@A-1/10@Z;1/12-1/14;15/00-15/06 | AA | AA00 PURPOSE |
AA01 | AA02 | AA03 | AA04 | AA05 | AA06 | AA07 | |||
| . Eliminating noise | . Preventing noise generation or emission | . Measuring | . Indication | . . Warnings | . . Noise indication | . . Tuning indication | ||||||
| AA11 | AA12 | AA14 | AA16 | |||||||||
| . Actual circuit improvements | . . Simplifying circuits, providing integrated circuits or making circuits economical | . Preventing malfunctions caused by noise | . Temperature compensation | |||||||||
| BB | BB00 APPLICATIONS |
BB01 | BB02 | BB03 | BB04 | BB05 | BB07 | BB08 | BB09 | BB10 | ||
| . Wireless equipment | . . Receivers | . . . Television broadcasting | . . . Radio broadcasting | . . . . Stereo broadcasting | . . Transmitters | . . Car-mounted radios | . . Navigational radios | . . Satellite communications equipment | ||||
| BB11 | BB12 | BB13 | BB14 | BB15 | BB16 | BB18 | BB19 | BB20 | ||||
| . Wire equipment | . . Telephones | . . Cable television | . Transmission paths | . Data communications | . . Data terminals | . Control equipment | . . Remote monitoring and control | . . . Remote control | ||||
| BB21 | BB23 | BB24 | BB25 | BB26 | BB27 | BB28 | BB29 | |||||
| . Digital equipment | . Recording and reproducing equipment | . . Magnetic | . . . Magnetic disks | . . . Tape recorders | . . . Video tape recorders (i.e., VTR) | . . Optical | . . . Optical disks | |||||
| BB31 | BB32 | BB33 | BB35 | |||||||||
| . Electronic circuits | . . Amplifying circuits | . . Phase locked loop (i.e., PLL) circuits | . Electrical parts for automobiles | |||||||||
| CC | CC00 MODULATING SYSTEMS |
CC01 | CC02 | CC04 | CC06 | |||||||
| . Amplitude modulation | . . Single sideband (i.e., SSB) modulation | . Frequency modulation (i.e., FM) or phase modulation (i.e., PM) | . Digital modulation | |||||||||
| DD | DD00 TYPES OF NOISE |
DD01 | DD02 | DD03 | DD04 | DD05 | DD07 | DD08 | DD09 | |||
| . External noise | . . Spatial noise | . . . Reflection disturbances, multi-pass disturbances or ghosts | . . . Interference waves, jamming or interference | . . . . Intermodulation disturbances | . . Signal line noise | . . . Induction noise | . . . . Crosstalk | |||||
| DD11 | DD12 | DD13 | DD15 | DD16 | DD17 | DD18 | DD19 | DD20 | ||||
| . . External power supply noise | . . . Power line induction noise or humming | . . . Noise produced when power supplies are turned on or off,or by external surges or by spikes | . Internal noise | . . Local noise | . . Detuning noise or inter-station noise | . . Heat noise, white noise or triangle noise | . . Induction noise within devices, crosstalk noise or crosstalk | . . Power supply noise within devices, noise produced when power supplies are turned on or off or humming | ||||
| DD21 | DD22 | DD23 | DD24 | DD25 | DD27 | DD28 | DD29 | DD30 | ||||
| . Pulsed noise, impact noise or impulse noise | . . Ignition noise | . . Digital signal noise, sampling noise or quantified noise | . . Control signal noise | . . Switching noise | . High frequency noise | . . Microwave noise | . Low frequency noise | . Periodic noise | ||||
| DD31 | DD32 | DD33 | DD34 | DD36 | DD37 | DD38 | ||||||
| . Mechanical system noise | . . Motor noise | . . Noise from electromagnetic conversion systems | . . Noise from mechanical contact | . Signal deterioration | . . Recording medium noise | . . . Dropouts | ||||||
| EE | EE00 DETECTING MEANS FOR ELIMINATING NOISE |
EE01 | EE02 | EE03 | EE04 | EE05 | EE06 | EE07 | ||||
| . Filters | . . Low-pass filters or low band filters | . . High-pass filters or high band filters | . . Band-pass filters | . . . Narrow band-pass filters | . . Band-rejection filters | . . Combinations of filters | ||||||
| EE11 | EE12 | EE13 | EE14 | EE15 | EE17 | EE18 | EE19 | |||||
| . Level detection | . . Noise level | . . Signal level | . . . Tone detection | . . . Carrier detection | . . Detector output | . . . AM demodulation | . . . FM demodulation or PM demodulation | |||||
| EE21 | EE22 | EE24 | EE25 | EE26 | EE27 | EE28 | EE30 | |||||
| . . High-frequency amplifier output | . . Intermediate-frequency amplifier output | . . Comparator output | . . . Voltage comparators | . . . Phase comparators, phase detectors or phase discriminators | . . Differentiating circuit output | . . Integrating circuit output | . Synchronicity detection | |||||
| EE31 | EE32 | EE33 | EE34 | EE35 | EE36 | EE37 | EE38 | EE39 | EE40 | |||
| . Using signals from other circuits | . . Automatic gain control (i.e., AGC) | . . Tuning circuits | . . . Indication | . . . Automatic frequency control (i.e., AFC) | . . . Sweep signals | . . Automatic phase control (i.e., APC) | . Using signal correlation | . . Doppler frequency detection | . Analog-digital conversion and sampling | |||
| FF | FF00 MEANS OF ELIMINATING NOISE |
FF01 | FF02 | FF03 | FF04 | FF05 | FF06 | FF07 | ||||
| . Noise eliminating filters | . . Transversal filters | . . Noise limitters | . . Traps or noise suppression lines | . . Adaptive filters | . . Frequency shifting | . . Changing frequency bandwidth | ||||||
| FF11 | FF12 | FF13 | FF14 | FF15 | FF16 | FF17 | FF18 | FF19 | ||||
| . Signal attenuation or cutoff | . . Squelch or noise muting | . . . Noise squelch | . . . Carrier squelch | . . . Tone squelch | . . . Squelch combinations | . . Changing squelch characteristics | . . . Squelch sensitivity adjustment | . . . . Hysteresis characteristics | ||||
| FF21 | FF22 | FF23 | FF24 | FF26 | FF27 | FF28 | FF29 | FF30 | ||||
| . . Noise blankers | . . Signal transmission paths are bypassed | . . . Full signal bypass | . . . Bypassing of noise only | . Optimizing frequency arrangement | . Signal interpolation | . Carrier replenishment | . Diversity | . Changing time constants | ||||
| FF31 | FF32 | FF33 | FF34 | FF35 | FF36 | FF37 | FF38 | FF39 | FF40 | |||
| . Signal operations | . . Signal canceling | . . Digital signal processors | . . Program control | . Structure | . . Shielding | . . Housings | . . Printed circuit boards | . . Plugs or connectors | . . Wire harnesses | |||
| GG | GG00 CIRCUITS USED FOR ELIMINATING NOISE |
GG01 | GG02 | GG03 | GG04 | GG05 | GG06 | |||||
| . Elements | . . Switches | . . . Electronic switches | . . Variable resistors | . . Wave absorbing materials | . . Optical elements | |||||||
| GG11 | GG12 | GG13 | GG14 | GG15 | GG16 | GG17 | GG18 | GG19 | GG20 | |||
| . Circuits | . . Attenuators or amplifiers | . . . Circuits whose gain is controlled | . . Gates | . . Operation amplifiers | . . Differential amplifiers | . . Logarithmic amplifiers | . . Push-pull amplifiers | . . Adders or subtracters | . . Multipliers or dividers | |||
| GG21 | GG22 | GG23 | GG24 | GG25 | GG26 | |||||||
| . . Tuning circuits | . . Oscillation circuits | . . . Voltage controlled oscillators (i.e., VCO) | . . Phase-locked loops (i.e., PLL) | . . . Loop filters | . . Mixing circuits or mixers | |||||||
| GG31 | GG32 | GG33 | GG34 | GG35 | ||||||||
| . . Antenna input circuits | . . High-frequency stages | . . Intermediate-frequency stages | . . Low-frequency stages | . . Power supply circuits | ||||||||
| GG41 | GG42 | GG43 | GG44 | GG45 | GG46 | GG47 | GG48 | GG49 | GG50 | |||
| . . Phase shifters | . . Delay circuits | . . . Shift registers | . . Differentiating circuits | . . Integrating circuits | . . Clip circuits or amplitude limiting circuits | . . Sample hold circuits | . . Analog-digital converters or digital-analog converters | . . Waveform shaping circuits | . . Multivibrators | |||
| GG51 | GG52 | GG53 | GG54 | GG55 | GG57 | |||||||
| . . Compression or expansion circuits | . . Voice synthesis circuits | . . Counting circuits | . . Timer circuits | . . Constant current circuits | . Central processing units (i.e., CPU) |