As a starting point to designing in an antenna for an application you should start with its performance in an environment without obstructions, in free space.  The standard way of doing this is to use an anechoic chamber.  The chamber must be of sufficient size such that the transmit and receive points are several wavelengths distance apart, and also the interior of the chamber should be filled with shapes that absorb rf and reflect at random angles, the familiar foam pyramids, to eliminate any influence caused by the walls of the chamber.

A cost effective alternative.

A chamber can be expensive to own and can take up a lot of space.  It can also be costly to rent one.  In a majority of cases you can use test equipment that delivers results that are closely matched to those from a chamber at a fraction of the cost, one example is the MegiQ.

Such anechoic test chambers can be large and expensive either to own or to rent, and in many cases it is possible to use simple test equipment such as the that from MegiQ in order to obtain results close to those which would be achieved at much higher cost in a chamber.

Measurements are taken in 3 axes to model the antenna’s performance.