Linear array of loop antennas with series excitation

We have considered a linear array, in which the radiators are loop antennas of a rhombic form. In the array, a central pair of loop antennas is excited from a power cable. The other loop antennas are exited from each other. We have researched numerically, by the method of moments, into the dependences of the key parameters of an antenna on the number of loops in the array. The array characteristics have been compared with the characteristics of a Yagi-Uda antenna.