Help regarding parameters study of antenna and other microstrip circuits such as gain

Dear All... Good afternoon

Can anyone describe the limitations of the parameter of antenna and other microstrip circuits such as return loss, efficiency, directivity, axial ratio etc. (for example the return must be less than -9.8 db upper and positive values are not permissible and VSWR must have the valve less than 2 for an antenna to perform). Can anybody give answer in the same way for directivity, gain axial ratio, different S parameters for Antenna as well as coupler , cross over shifter and other circuits also.

Please attach related document if anybody have it.
or send the link.

Thanks in advance