0
A ground station parabolic antenna has an efficiency of 0.6 and a gain of 50dB at a frequency of 6 GHz Calculate the diameter of the antenna?
Wiki User
∙ 14y ago
For 'f' in GHz and 'D' in feet, I always use Gant, dB = 20 log( f x D ) + 7.5
But I think that's for 55% efficiency. If the eff is 60%, that's 20log(60/55) better = another 0.75 dB. So let's make it
Gant, dB = 20 log( f x D ) + 8.25
20 log( 6 D ) + 8.25 = 50
20 log( 6 D ) = 41.75
log ( 6 D ) = 2.0875
6 D = 102.0875
D = 102.0875 / 6 = 20.39 ft = 6.21 meters (rounded, but it looks reasonable; hope it's close)
Wiki User
∙ 14y ago
Add your answer:
Earn +20 pts
How do you calculate runout of diameter?
use a dial indicator
How do you calculate economical pipe diameter for water flowing in circular pipe?
no
A piece of wire 100 m long has a diameter of 1 mm with a resistance of 2 ohms calculate the resistance of the same wire 2 km long with the same current?
If the wire length is 100m and the Diameter is 1mm calculate the Resistance of wire?
Turntable which is 110 v 60 hz frequency I know I can change the voltage with an converter to 220 v - but can you somehow change the frequency to 50 hz?
My BIC turntable accomplishes this with a different sized belt pully. They have a U.S. diameter (60 HZ) and a U.K. diameter. Their parts department stock both. Joe
How do you calculate swl for mooring rope of 68mm?
Yeah! (D X 8), where, D= Diameter!
What is the equation linking power of a radio telescope and the diameter of its dish?
For any parabolic antenna used to focus radio waves, the following formula is pretty good. GdB = 20 log( F D ) + 7.5 G = the gain of the antenna in dB, compared to an isotropic antenna F = the frequency, in GHz, at which the gain is 'G' D = the diameter of the parabola, in feet The formula assumes that the antenna's efficiency is 50% . If this bothers you and you want to assume 100% efficiency, simply change the ' 7.5 ' to ' 10.5 '. The formula shows that if the diameter of the antenna is doubled, or if the frequency of interest is doubled, then the antenna has four times as much gain ( + 6 dB ).
Calculate surface area of parabolic reflector of Diameter 5.5 ft and depth of 2.75 ft for simple parabolic segment with y equals x squared?
My answer is: http://img854.imageshack.us/img854/4407/50198806.png how i wish i can link [img] [/img] here. sigh...
How do you find the focal length of a parabolic dish for placement of the feedhorn?
Precisely measure the diameter (D) of the dish and depth (d) at the center of the dish. With these measurements, calculate the focal length (F) using the following formula: F=D2/16d
Calculate the area of the ball with a diameter of 12 metres?
Calculate the area of the ball with a diameter of 12 metres
How do you calculate the diameter of one inch?
Calculate the sum
How do you calculate radius from pipe diameter?
diameter = 2 * radius
How do you calculate radius of the circle when you do not have diameter?
Double the Radius to Calculate the Diameter.
How do you calculate the length of a cable if its diameter is 14 mm?
You don't. You can calculate iits radius and cross-sectional area but its diameter has insufficient information to calculate its length
How do you calculate the radius given the diameter?
Radius of a circle = diameter/2
How do you calculate field diameter?
Field diameter of lens B equals field diameter of lens A times total magnification of lens A divided by total magnification of lens B
How do you calculate the diameter of a 3 acre circle?
Divide the area by Pi to get the diameter.
How do you calculate the diameter from the area?
Divide the area by pi (= 3.14159 approx) to get diameter.
