Hi khirat,
microstrip patch antennas are passive devices, no voltage, current, or any signal can vary its behavior, and so when designed and printed on a board, gives only a specific response. You need to vary the physical dimensions of the layout to obtain a different response, this means that once printed on a board, a patch antenna's response is permanent.
you can just use the two separate antennas you designed and then connect them to a switch. you can just switch between the two antennas if you want to use them both on a single system.
Hope this helps, Goodluck!