###### Abstract  
A high-dimension ratio, octagonal-shaped, super-wideband (SWB) monopole antenna was proposed in this paper. The proposed antenna was composed of an octagonal-structured radiating patch with a flower-shaped slot fed by a linearly tapering microstrip line and a rectangular partial ground fabricated on a Rogers 5880 dielectric substrate, with an overall dimension of \(14\times 16\times 0.787\) mm\({}^{3}\). The designed antenna exhibits SWB characteristics over the frequency range of 3.71 to 337.88 GHz at \(1511\leq-10\) dB, VSWR \(<2\), a bandwidth ratio (BR) of 91.07:1, and a very high BDR of 6057.27. The proposed SWB antenna was designed, simulated, and analyzed using Ansys high-frequency structural simulator (HFSS). The simulated and measured findings have good confirmability, making them ideal for future-generation mobile networks, due to their strong radiation properties, compactness, and extremely wide bandwidth. polygon structure; tapered feed; super-wideband (SWB); bandwidth dimension ratio (BDR); peak gain; radiation efficiency +
Footnote †: journal: _sciences_  
monopole antenna is a promising SWB antenna due to its compact dimensions, inexpensive, linear design, incredibly high BW impedance, and simplicity of integration into handheld devices [6; 7; 8]. Many wideband antennas were reported in the literature for SWB applications, such as a concentric Mickey-Mouse-shaped monopole radiator with a semi-elliptical ground for super-wideband (SWB) application, which was presented with an electrical size of 0.16 \(\lambda\)\(\times\) 0.18 \(\lambda\) (\(\lambda\) lowest cutoff frequency). The antenna operates over the frequency range of 1.22-47.5 GHz and offers an FBW of 190% and a RBW of 38.9:1 with a peak gain of 0.5 to 10.3 dBi [9]. A medically designed pill-shaped microstrip patch antenna [10] with a physical size of 41 \(\times\) 32 \(\times\) 16 mm\({}^{3}\) was designed to achieve a peak gain of 8.2 dBi and operates over 2-95 GHz with BDR 3095, FBW 180%, and a low efficiency of 67%. A novel monopole antenna with a partial ground plane in the shape of a trapezoid and patches in the shape of semicircles with a tapered feed line was designed to achieve a high bandwidth dimension ratio (BDR) of 4261.007. An antenna operates in the frequency range of 1.30 to 20 GHz with an impedance bandwidth of 175.58%, a low ratio bandwidth of 15.38:1, and a low average peak gain of 4.18 dBi [11]. A compact SWB antenna was designed on a flexible Ultralam 3850 laminate substrate for 5G and IOT applications with dimensions of 60 \(\times\) 40 \(\times\) 0.1 mm\({}^{3}\) and operates in the frequency band from 1.74 to 100 GHz with a 57.47:1 ratio bandwidth (BW). A peak gain of 9.24 dB at 65.6 GHz and even lower than 0 dB of gain was observed in the designed band [12]. A circularly shaped asymmetrical dipole antenna with two dielectric substrates of low permittivity was designed with a 21.9:1 ratio bandwidth and VSWR \(<\) 2 [13]. A triple elliptical monopole antenna with overall dimensions of 27 mm \(\times\) 29.5 mm was fabricated on a Roger's RT-Duroid 5880 substrate with a relative permittivity of (\(\epsilon_{\mathrm{r}}\)) = 2.2 and a loss tangent of (tan \(\delta\)) = 0.0009 and covers the frequency band from 1.91 to 43.5 GHz at S11 \(\leq-\)10 dB with a very BDR of 5761.87, a FBW \(>\) 183.17%, and a RBW of 22.77:1 [14]. A wide band scarecrow-shaped ultra-wide band (UWB) antenna using CPW and microstrip line-feeding technique was reported with a dimension of 5 \(\times\) 20 \(\times\) 1.6 mm\({}^{3}\). The IBW of a CPW-fed antenna and a microstrip-line-fed antenna was 2.51-16.48 GHz (147.13%) and 2.86-16.17 GHz (139.88%), respectively [15]. A trapezoid-shaped monopole radiator fed by a triangular, tapered feed line and a semicircular ground was presented. The electrical size was 0.16 \(\lambda\)\(\times\) 0.27 \(\lambda\)c and offered a SWB range of 1.42-90 GHz at S11 \(\leq-\)10 dB, a bandwidth ratio of 63.30:1, and a VSWR \(\leq\) 2 [16].