Antena IoT: 30cm = 10 dB
· 7 min read · Technical Whitepapers
10 dBi no amplifica 5x. Enfoca energia en haz estrecho.
La antena es el componente mas barato en un despliegue IoT y la causa raiz mas comun de "problemas de conectividad" que generan visitas al sitio. Un router de primer nivel con una antena mal elegida rinde menos que un router de gama media con una antena correctamente colocada. La ganancia de antena no es amplificacion —es enfoque.
La Ganancia No Es Amplificacion
Una antena de 10 dBi no amplifica tu senal 5 veces mas que una de 2 dBi. Enfoca la misma energia en un haz mas estrecho. Consecuencia practica: mas ganancia = patron de radiacion mas plano. Una omnidireccional de 9 dBi tiene un ancho de haz vertical de aproximadamente 15-20 grados.
Preguntas frecuentes
Higher dBi means better signal, right?
No. Higher dBi means more focused signal — narrower beam. A 9 dBi omni antenna in a multi-story building can miss floors entirely because the beam is too flat. Match gain to the coverage pattern you need, not the highest number on the box.
Can I use just one antenna on a MIMO router?
Technically yes, but you lose 40-60% throughput and diversity protection against multipath fading. Always use both (or all four) antenna ports with identical antenna models, spaced at least 30 cm apart, at 90-degree polarization offset.
Internal or external antenna — which should I spec?
If the router is in a metal cabinet: external, mandatory. The enclosure attenuates signal by 15-30 dB. If the device is portable, indoor, and within 50m line-of-sight: internal is fine. The enclosure decides — not the datasheet.