The criticality of the dimension is to be noted.
Even though a larger VSWR BW of 128 MHz is obtained for L2 = 2.90 cm due to the loop in the impedance plot, the minimum AR is 2 dB at f 0 = 3.04 GHz. For L2 = 2.92 cm, the VSWR BW is slightly reduced to 106 MHz, but the minimum AR at f 0 = 3.027 GHz is improved to 0.07 dB. In this case, the BW for AR £ 3 dB is 25 MHz (0.8%).
The value of L1 /L2 = 3.0/2.92 = 1.027 implies separation of 2.7% between the two resonant lengths, which is slightly greater than the VSWR BW (1.8%) of the square patch of length = 3 cm. For this feed, LHCP is obtained, and if the feed is shifted to the other diagonal, then RHCP is obtained.