Where does antenna collide?

In radio engineering an antenna is the structure that converts a guided electrical signal in a circuit into a radiated electromagnetic wave in free space and, reciprocally, intercepts an incoming wave and delivers it to a receiver; it is the two-way transducer at the edge of every radio link. Kraus's Antennas and Balanis's Antenna theory develop the radiation pattern, gain, impedance, and effective aperture that describe how well it does this. The referent is a radiating and receiving conductor borrowed by analogy from the insect's feeler, and it shares nothing but the name with the biological organ or the cell's cilium.[1][2]

Unit

The radiator's gain, directivity, and effective aperture as it couples circuit to free space

Recovery means

Not applicable

Measured by

Characterised by the measured radiation pattern, gain, input impedance, and bandwidth on an antenna range

In cell biology the primary cilium is a single, non-motile projection from the surface of most vertebrate cells that concentrates receptors and signaling machinery and so acts as the cell's antenna, sampling chemical and mechanical cues from its surroundings and relaying them inward. Singla and Reiter's The primary cilium as the cell's antenna framed this sensory role and its place in pathways such as Hedgehog signaling. The referent is a sensory organelle, a metaphor reaching back to the insect's feeler, and it is a different construct again from a radio radiator, tied to the others only through the shared word.[3]

Unit

The organelle as a signaling hub, characterised by the receptors it concentrates

Recovery means

Not applicable

Measured by

Assessed by imaging of ciliary structure and by the localisation and activity of receptors along the cilium