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5 results for “antenna”

Formulae (5)

d \approx 1.23\sqrt{h}

Maximum line-of-sight range to the radio horizon for a VHF antenna, driven by antenna height and the curvature of the Earth.

\lambda = \dfrac{c}{f}

Wavelength of a radio signal is the speed of light divided by its frequency; it sets antenna length and dish sizing.

EIRP_{dBW} = P_t + G_t - L_c

Apparent power a transmitter would need if it radiated equally in all directions; combines transmit power, antenna gain and cable loss.

G = \eta\left(\dfrac{\pi D}{\lambda}\right)^2

Gain of a dish antenna rises with aperture area and falls with wavelength, scaled by aperture efficiency.

P_r = \dfrac{P_t G^2 \lambda^2 \sigma}{(4\pi)^3 R^4}

Received echo power for a monostatic radar, combining transmit power, antenna gain, target size and range.