H
SECTION H — ELECTRICITY
 H04
ELECTRIC COMMUNICATION TECHNIQUE
 H04B
TRANSMISSION (broadcast communication H04H; multiplex systems H04J; secret communication H04K)
 H04B

Note(s)

This sub-class deals with the transmission of information-carrying signals, the transmission being independent of the nature of the information, and includes monitoring and testing arrangements and the suppression and limitation of noise and interference.

 H04B 1/00
Details of systems covered by groups H04B 3/00-H04B 13/00 (tuning resonant circuits H03J)
 H04B 1/02
·  Transmitters (spatial arrangements of component circuits in radio pills for living beings A61B 5/07)
 H04B 1/03
·  ·  Constructional details, e.g. casings, housings  [2]
 H04B 1/034
·  ·  ·  Portable transmitters  [2]
 H04B 1/036
·  ·  ·  Cooling arrangements (cooling transformers H01F 27/08; cooling discharge tubes H01J 7/24, H01J 19/74)  [2]
 H04B 1/04
·  ·  Circuits (of television transmitters H04N 5/38)
 H04B 1/06
·  Receivers (control of amplification H03G; television receivers H04N 5/44, H04N 5/64)
 H04B 1/08
·  ·  Constructional details, e.g. cabinet
 H04B 1/10
·  ·  Means associated with receiver for limiting or suppressing noise or interference
 H04B 1/12
·  ·  ·  Neutralising, balancing, or compensation arrangements
 H04B 1/14
·  ·  ·  Automatic detuning arrangements
 H04B 1/16
·  ·  Circuits
 H04B 1/18
·  ·  ·  Input circuits, e.g. for coupling to an aerial or a transmission line (input circuits for amplifiers in general H03F; coupling networks between aerials or lines and receivers independent of the nature of the receiver H03H)
 H04B 1/20
·  ·  ·  for coupling gramophone pick-up, recorder output, or microphone to receiver
 H04B 1/22
·  ·  ·  for receivers in which no local oscillation is generated
 H04B 1/24
·  ·  ·  ·  the receiver comprising at least one semiconductor device having three or more electrodes
 H04B 1/26
·  ·  ·  for superheterodyne receivers (multiple frequency-changing H03D 7/16)
 H04B 1/28
·  ·  ·  ·  the receiver comprising at least one semiconductor device having three or more electrodes
 H04B 1/30
·  ·  ·  for homodyne or synchrodyne receivers (demodulator circuits H03D 1/22)
 H04B 1/32
( transferred to H03J 7/18 )
 H04B 1/34
( transferred to H03J 7/22, H03J 7/26 )
 H04B 1/36
( transferred to H03J 7/32 )
 H04B 1/38
·  Transceivers, i.e. devices in which transmitter and receiver form a structural unit and in which at least one part is used for functions of transmitting and receiving
 H04B 1/40
·  ·  Circuits
 H04B 1/44
·  ·  ·  Transmit/receive switching (tubes therefor H01J 17/64; waveguide switches per se H01P 1/10)  [2]
 H04B 1/46
·  ·  ·  ·  by voice-frequency signals; by pilot signals
 H04B 1/48
·  ·  ·  ·  in circuit for connecting transmitter and receiver to a common transmission path, e.g. by energy of transmitter (in radar systems G01S)
 H04B 1/50
·  ·  ·  using different frequencies for the two directions of communication
 H04B 1/52
·  ·  ·  ·  Hybrid arrangements, i.e. for transition from single-path two-way transmission to single transmission on each of two paths, or vice versa
 H04B 1/54
·  ·  ·  using the same frequency for both directions of communication (H04B 1/44 takes precedence)
 H04B 1/56
·  ·  ·  ·  with provision for simultaneous communication in both directions
 H04B 1/58
·  ·  ·  ·  Hybrid arrangements, i.e. for transition from single-path two-way transmission to single transmission on each of two paths, or vice versa
 H04B 1/59
·  Responders; Transponders (relay systems H04B 7/14)
 H04B 1/60
·  Supervising unattended repeaters
 H04B 1/62
·  Modifications of systems to provide a predistortion of the signal in the transmitter and corresponding correction in the receiver, e.g. to improve the signal/noise ratio
 H04B 1/64
·  ·  Volume compression or expansion arrangements
 H04B 1/66
·  Modifications of systems to reduce bandwidth of signals (in pictorial communication or television systems H04N); Modifications of systems to improve efficiency of transmission
 H04B 1/68
·  ·  by wholly or partially suppressing the carrier or one side band
 H04B 1/70
·  using a sub-carrier
 H04B 1/72
·  Circuits or components for simulating aerials, e.g. dummy aerial (dissipative waveguide terminations H01P 1/26)
 H04B 1/74
·  Modifications of systems to increase reliability, e.g. using redundant or spare channels or apparatus  [3]
 H04B 1/76
·  Pilot transmitters or receivers for control of transmission or for equalising  [3]
 H04B 3/00
Line transmission systems (combined with near-field transmission systems H04B 5/00; constructional features of cables H01B 11/00)
 H04B 3/02
·  Details
 H04B 3/03
·  ·  Hybrid circuits (for transceivers H04B 1/52, H04B 1/58; hybrid junctions of the waveguide type H01P 5/16)  [3]
 H04B 3/04
·  ·  Control of transmission; Equalising (control of amplification in general H03G)
 H04B 3/06
·  ·  ·  by the transmitted signal
 H04B 3/08
·  ·  ·  ·  in negative-feedback path of line amplifier
 H04B 3/10
·  ·  ·  by pilot signal
 H04B 3/11
·  ·  ·  ·  using pilot wire (H04B 3/12 take precedence)  [3]
 H04B 3/12
·  ·  ·  ·  in negative-feedback path of line amplifier
 H04B 3/14
·  ·  ·  characterised by the equalising network used
 H04B 3/16
·  ·  ·  characterised by the negative-impedance network used
 H04B 3/18
·  ·  ·  ·  wherein the network comprises semiconductor devices
 H04B 3/20
·  ·  Reducing echo effects or singing; Opening or closing transmitting path; Conditioning for transmission in one direction or the other
 H04B 3/21
·  ·  ·  using a set of bandfilters  [3]
 H04B 3/22
( transferred to H04B 3/21, H04B 3/23, covered by H04B 3/20 )
 H04B 3/23
·  ·  ·  using a replica of transmitted signal in the time domain, e.g. echo cancellers  [3]
 H04B 3/24
( transferred to H04B 3/21, H04B 3/23, covered by H04B 3/20 )
 H04B 3/26
·  ·  Improving frequency characteristic by the use of loading coils (loading coils per se H01F 17/08)
 H04B 3/28
·  ·  Reducing interference caused by currents induced in cable sheathing or armouring
 H04B 3/30
·  ·  Reducing interference caused by unbalance current in a normally balanced line
 H04B 3/32
·  ·  Reducing cross-talk, e.g. by compensating
 H04B 3/34
·  ·  ·  by systematic interconnection of lengths of cable during laying; by addition of balancing components to cable during laying
 H04B 3/36
·  ·  Repeater circuits (H04B 3/58 takes precedence; amplifiers therefor H03F)
 H04B 3/38
·  ·  ·  for signals in two different frequency ranges transmitted in opposite directions over the same transmission path
 H04B 3/40
·  ·  Artificial lines; Networks simulating a line of certain length
 H04B 3/42
·  ·  Circuits for by-passing of ringing signals
 H04B 3/44
·  ·  Arrangements for feeding power to a repeater along the transmission line
 H04B 3/46
·  ·  Monitoring; Testing
 H04B 3/48
·  ·  ·  Testing attenuation
 H04B 3/50
·  Systems for transmission between fixed stations via two-conductor transmission lines (H04B 3/54 takes precedence)
 H04B 3/52
·  Systems for transmission between fixed stations via waveguides
 H04B 3/54
·  Systems for transmission via power distribution lines (remote indication of power network conditions, remote control of switching means in a power distribution network H02J 13/00)
 H04B 3/56
·  ·  Circuits for coupling, blocking, or by-passing of signals
 H04B 3/58
·  ·  Repeater circuits (amplifiers therefor H03F)
 H04B 3/60
·  Systems for communication between relatively movable stations, e.g. for communication with lift (H04B 3/54 takes precedence)
 H04B 5/00
Near-field transmission systems, e.g. inductive loop type
 H04B 5/02
·  using transceiver
 H04B 5/04
·  Calling systems, e.g. paging system
 H04B 5/06
·  using a portable transmitter associated with a microphone
 H04B 7/00
Radio transmission systems, i.e. using radiation field (H04B 9/00, H04B 15/00 take precedence)
 H04B 7/005
·  Control of transmission; Equalising  [3]
 H04B 7/01
·  Reducing phase shift  [3]
 H04B 7/015
·  Reducing echo effects  [3]
 H04B 7/02
·  Diversity systems (for direction finding G01S 3/72; aerial arrays or systems H01Q)
 H04B 7/04
·  ·  using a plurality of spaced independent aerials
 H04B 7/06
·  ·  ·  at transmitting station, e.g. time diversity
 H04B 7/08
·  ·  ·  at receiving station, e.g. space diversity
 H04B 7/10
·  ·  using a single aerial system characterised by its polarisation or directive properties, e.g. polarisation diversity, direction diversity
 H04B 7/12
·  ·  Frequency-diversity systems
 H04B 7/14
·  Relay systems (interrogator-responder radar systems G01S 13/74)  [2]
 H04B 7/145
·  ·  Passive relay systems  [2]
 H04B 7/15
·  ·  Active relay systems  [2]
 H04B 7/155
·  ·  ·  Ground-based stations  [2]
 H04B 7/165
·  ·  ·  ·  employing angle modulation  [2]
 H04B 7/17
·  ·  ·  ·  employing pulse modulation, e.g. pulse code modulation  [2]
 H04B 7/185
·  ·  ·  Space-based or airborne stations  [2]
 H04B 7/19
·  ·  ·  ·  Earth-synchronous stations  [2]
 H04B 7/195
·  ·  ·  ·  Non-synchronous stations  [2]
 H04B 7/22
·  Scatter propagation systems
 H04B 7/24
·  for communication between two or more posts  [2]
 H04B 7/26
·  ·  at least one of which is mobile  [2]
 H04B 9/00
Transmission systems employing electromagnetic waves other than radio waves, e.g. light, infra-red (controlling, e.g. modulating, of light beams G02F 1/00; demodulating, transferring the modulation, or frequency changing, of light G02F 2/00)
 H04B 11/00
Transmission systems employing sonic, ultrasonic or infrasonic waves
 H04B 12/00
Transmission systems characterised by the use of pulse modulation (in radio transmission relays H04B 7/17)  [3]
 H04B 12/02
·  using pulse code modulation (pulse code modulation per se H03K 13/01)  [3]
 H04B 12/04
·  using delta or differential modulation  [3]
 H04B 13/00
Transmission systems not provided for in the preceding groups
 H04B 13/02
·  Transmission systems in which the medium consists of the earth or a large mass of water thereon, e.g. earth telegraphy (line transmission systems with earth or water return H04B 3/00)
 H04B 15/00
Suppression or limitation of noise or interference (by means associated with receiver H04B 1/10)
 H04B 15/02
·  Reducing interference from electric apparatus by means located at or near the interfering apparatus (structural association with dynamo-electric machines H02K 11/00)
 H04B 15/04
·  ·  the interference being caused by substantially sinusoidal oscillations, e.g. in a receiver, in a tape-recorder (reducing parasitic oscillations H03B, H03F; screening H05K 9/00)
 H04B 15/06
·  ·  ·  by local oscillators of receivers
 H04B 17/00
Monitoring; Testing  [2]
 H04B 17/02
·  of relay systems  [2]