This work presents a compact reconfigurable antenna based on fractal geometry. The investigation discusses the challenges of lower antenna gain and bandwidth, critical for efficient data propagation in 5G systems, particularly for low-profile devices. Its goal is to develop a small, multiband antenna capable of operating in all current and future 5G bands and improve bandwidth and gain for mm-wave and sub-6 GHz applications. The proposed design covers the sub-6 band (2.8, 3.9, 4, 6.2) GHz and the mm-wave band (24.4, 27.1, 28.5, 29.3, 30.6, 33.9, 34.6, 35.2, 38.8, 44.4, 45.1, 59.7, 61.5, 62.3, 65.2, 67.4 and 69.5) GHz with S11 less than -10 dB. A maximum gain of 12.8 dB and a radiation efficiency of 94% are achieved. A partial ground plane with a 50 Ω feed line is used in this design. The antenna is printed on a Roger RT 5880 substrate with a relative dielectric constant 2.2 with a total dimension of 35×32.5×0.8 mm³. The proposed design is simulated using CST software, ensuring accurate calculations and performance evaluation.