IPC Definitions - January 01, 2012

H04B 1/00 - Definition fr

Definition statement

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

Informative references

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

Glossary of terms

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.