Can someone please help me with these questions?

1.Design a pyramidal horn antenna at 5775 MHz to offer a gain of 20 dB. You may assume any appropriate value for the wave guide dimensions.

2.For a gigabit wireless backhaul link ( LOS ), the data rate is 2Gbps. The frequency of operation is 11GHz. Suggest an appropriate antenna and substantiate your choice based on a comparison with other possible antenna structures.

3.Design a matching section ( patch / transmission line ) to match a 50 ohm source to 75 ohm load . You may use any of the freeware available on-line such as “AppCad” or “SMITH ” to do the matching.

Sounds like a student assignment.

Now, if you were in a fraternity, you could just search the files for last year's solutions from your borthers. Fortunately for you, you're probably not a frat boy, so do yourself an even bigger service and figure these out on your own.

You might be asked something similar on an interview one day and it sure would be nice to know how to come up with the answers on your own.

Good luck - seriously.

Regarding the third one - try looking it up in Microwave engineering by Pozar, this and many other problems are solved and explained there.

2 - check some we sites of companies that produce antennas and substrats (like Rogers). Simply type "Wi-Fi" in the browser and you should find thousands of solutions.

3. The gain and frequency of a horn antenna depends on the dimensions of the aperture and the lenght of the horn. That should be your start point.

Best wishes and good luck

1) 6x8 inch aperture, 12 inches long.
2) Frequency scale the above antenna, or search google
3) incomplete question, no bandwidth, no spec.
Sounds like a homework assignment.