Assertion: helical antenna | /r/ObjectUse | used for application
Facets:
value: frequently
type: TEMPORAL
Source sentences:
text: In radio transmission, circular polarisation is often used where the relative orientation of the transmitting and receiving antennas cannot be easily controlled, such as in animal tracking and spacecraft communications, or where the polarisation of the signal may change, so end-fire helical antennas are frequently used for these applications.