IPC Definitions - January 01, 2012
H04B 1/00 - Definition
This main group covers:
Details of transmission systems that are general for transmission systems covered by two or more groups H04B 3/00-H04B 13/00.
Details of transmission systems not characterized by the medium used for transmission.
References relevant to classification in this main group
This main group does not cover:
Demodulation or transference of modulation from one carrier to another | H03D |
Attention is drawn to the following places, which may be of interest for search:
Spatial arrangements of component circuits in radio pills for living beings | A61B 5/07 |
Waveguides; Resonators, lines or other devices of the waveguide type | H01P |
In this main group, the following terms or expressions are used with the meaning indicated:
Homodyne receiver | A receiver which involves multiplying the modulated received signal by a local oscillator which has the same frequency as that associated with the received signal, so that the received signal will be directly converted into the baseband. |
Superheterodyne receiver | A receiver in which the frequency of the incoming signal is reduced in a mixer or frequency changer by heterodyning with another frequency at the local oscillator. (Heterodyning: combining two sinusoidal frequencies radio frequency waves in a non-linear device resulting in sum and difference frequencies). |
Synchrodyne receiver | A receiver in which a mixing carrier signal is inserted in exact synchronism with the original carrier at the transmitter. Used for the selective detection of signals coded in a certain way. |