Re: antenna prolem related to yagi yuda or recmend me any ot
HI!
First of all I think that to obtain 50 ohm feed impedence you have to use some matching technique (beta match, omega match, ...) Don't forget to use a balun!!
For the other specs... it is hard to say... you can write a parametrized .nec file and do some testing.
I think that a 4 elements yagi could perform as you need.
You could try with DL6WU design (search the internet), I'm not sure that
4NEC2 or yagimax have some tools that will allow you to optimize your design for your specs.
BR