Questions to SATCOM antennas

Hello,

I have questions to the two attached presentation slides.

Slide 1: Why is C band antenna diameter much larger than L, Ku and Ka ones?

Slide 2: It is included that antennas for TDMA are greater than for spreading spectrum. As far as I know different antennas have different patterns, but why do transmission modes play a role?

Could anybody kindly explain these for me?

Senmeis

because that is how you get the required gain

the higher in freq you go, the smaller the antenna needs to be to get the same amount of gain


not sure ion the second question

KVH , uses shorter wavelength Ku band than C-band using traditional TDMA which used a modulation that uses more bandwidth per channel.

But L < C < Ku.

I think you refer to the relationship:

G ~ A/λ2

But λC < λL

Senmeis