Dish Gain verses Frequency
These were calculated from the equation in
Krauss "Radio Astronomy" equation 6-19, page 6-6.
The equation is: 10 log ( k (4π/λ2) A )
where k is the feed efficiency, lambda is the wavelength
and A is the effective aperture (262 square meters).
The term 10 Log was added.
The feed efficiencies shown here are 50% and 70%.
The former is a modest one to be used. Typically the
satellite industry has used 55%, where as a very well
designed feed can get up to around 70% on a very
good day. - John Ewan
For more information see dish gain comments by Joseph DiVerdi
| A=262 | c=3E+10 | |||||||||||||
| Gain | Gain | |||||||||||||
| Freq | λ | k=50% | k=70% | |||||||||||
| MHz | m | dB | dB | |||||||||||
| 2400 | 0.1249 | 50.2 | 51.7 | |||||||||||
| 2000 | 0.1499 | 48.6 | 50.1 | |||||||||||
| 1665 | 0.1801 | 47.1 | 48.5 | |||||||||||
| 1420 | 0.2111 | 45.7 | 47.1 | |||||||||||
| 1296 | 0.2313 | 44.9 | 46.3 | |||||||||||
| 1000 | 0.2998 | 42.6 | 44.1 | |||||||||||
| 870 | 0.3446 | 41.4 | 42.9 | |||||||||||
| 618 | 0.4851 | 38.4 | 39.9 | |||||||||||
| 433 | 0.6924 | 35.4 | 36.8 | |||||||||||
| 300 | 0.9993 | 32.2 | 33.6 | |||||||||||
| 209 | 1.4344 | 29.0 | 30.5 | |||||||||||
| 160 | 1.8737 | 26.7 | 28.2 |
