specification Center frequency: 5.8 GHz Bandwidth: 660 MHZ (5.47-6.13ghz) Match: S11 < -20 dB, VSWR < 1.22 (at the center frequency) Axial ratio: < 1.3 DBi antenna gain: 9.4 Half power beam width: 55 ° (horizontal and vertical) Radiation efficiency: 83.5% These values are based on simulation and the actual measurements are as follows (they are very similar). Due to the change of the FR4 dielectric constant, the center frequency may be transferred between batches. And not all FR4 brands have the same dielectric constant. The frequency conversion to 100 MHz is normal.