hello,
How many antennas have you got in your array ?
What technology do you use ? (microstrip ?)
T-junction is not difficult to simulate and optimize.
If you know the different impedance, i mean the antenna impedance and feed impedance you have to use a lambda/4 transformer.
Example : 2 antenna feed by a 50 ohms line, antenna impedance is 110 ohms. So you have 110 // 110 = 55 ohms. So you have to design two microstrip lines at 110 ohms (caracteristic impedance) connected to antenna. After to match the 55 ohms junction point of this two antennas to the 50 ohms line, you design a lambda/ 4 transformer with a SQRT(55 * 50)= 52.44 ohms caracteristic impedance. With an optimization, it's not very difficult ( ex : use ADS or ansoft designer).
Good work.