A compact wideband circularly polarized fractal slot antenna with rectangular island for X-band satellite applications

Figures & data

Figure 1. Spidron-fractal slot antenna: (a) Front view and (b) Back view.

Figure 2. Right angle triangles forming the spidron shape.

Figure 3. Spidron shape.

Figure 4. Spidron-fractal slot antenna with rectangular embedded island: (a) Front view and (b) Back view.

Figure 5. Simulated reflection-coefficient |S₁₁| of the SFSA-NI antenna at different values of F_L.

Figure 6. Simulated axial-ratio (AR)| of the SFSA-NI antenna at different values of F_L.

Table 1. optimized dimensions of SFSA-NI antenna.

Parameter	Hs	Sx	Sy	LF	WF	FL	L	W
Value (mm)	17	2.6	2.17	10.1	1.45	13.33	19.7	23

Table 2. Optimized dimensions of SFSA-RI antenna.

Parameter	Hs	Sx	Sy	LF	WF	FL	LR	WR	RP	Rg	L	W
Value (mm)	17	2.6	2.17	10.1	1.45	13.33	6.25	7.87	2.34	0.16	19.7	23

Figure 7. Simulated reflection-coefficient |S₁₁| of the SFSA-RI antenna at different values of L_R.

Figure 8. Simulated axial-ratio (AR) of the SFSA-RI antenna at different values of L_R.

Figure 9. Simulated reflection-coefficient |S₁₁| of the SFSA-RI antenna at different values of W_R.

Figure 10. Simulated axial-ratio (AR) of the SFSA-RI antenna at different values of W_R.

Figure 11. Simulated reflection-coefficient |S₁₁| of the SFSA-RI antenna at different values of R_P.

Figure 12. Simulated axial-ratio (AR) of the SFSA-RI antenna at different values of R_P.

Figure 13. Fabricated SFSA-RI antenna: (a) Front view, (b) Back view.

Figure 14. Fabricated SFSA-RI antenna measurement in the anechoic chamber.

Figure 15. Simulated surface current distribution at 7.5 GHz of the SFSA-RI antenna with embedded island at phase: (a) 0°, (b) 90°, (c) 180°, (d) 270°.

Figure 16. Simulated surface current distribution at 8.15 GHz of the SFSA-RI antenna with embedded island at phase: (a) 0°, (b) 90°, (c) 180°, (d) 270°.

Figure 17. Simulated surface current distribution at 9 GHz of the SFSA-RI antenna with embedded island at phase: (a) 0°, (b) 90°, (c) 180°, (d) 270°.

Figure 18. Simulated and measured LHCP and RHCP, radiation patterns at 7.5 GHz: (a) E-plane (phi = 0°), (b) H-plane (phi = 90°).

Figure 19. Simulated and measured LHCP and RHCP, radiation patterns at 8.15 GHz: (a) E-plane (phi = 0°), (b) H-plane (phi = 90°).

Figure 20. Simulated and measured LHCP and RHCP, radiation patterns at 9 GHz: (a) E-plane (phi = 0°), (b) H-plane (phi = 90°).

Figure 21. Measured vs simulated radiation pattern polar plot (theta vs dBi): (a) E-plane (phi = 0) at 7.5 GHz, (b) H-plane (phi = 90) at 7.5 GHz, (c) E-plane (phi = 0) at 8.15 GHz, (d) H-plane (phi = 90) at 8.15 GHz, (e) E-plane (phi = 0) at 9 GHz, (f) H-plane (phi = 90) at 9 GHz.

Figure 22. Measured vs simulated reflection-coefficient |S₁₁| of the SFSA-RI antenna.

Figure 23. Measured vs simulated axial-ratio (AR) of the SFSA-RI antenna.

Figure 24. Measured vs simulated gain of the SFSA-RI antenna.

Figure 25. Measured vs simulated antenna efficiency of the SFSA-RI antenna.

Table 3. Comparison with most recent designs of X-band antennas.

References	Bandwidth (Hz)	Axial-ratio 3-dB Bandwidth (Hz)	Dual Circular Polarization	Maximum Gain (dBi)	Antenna Size (mm^3)
(Arnaud et al., 2020)	8.025-8.4 GHz (370 MHz)	8.025-8.4 GHz (370 MHz)	Yes	5 dBi	Diameter: 238 mm (6.52λ0) Height: 185 mm (5.13λ0)
(Leszkowska et al., 2021)	8-9.7 GHz (1.7 GHz)	8.3-8.88 GHz (580 MHz)	No	14 dBi	(Length × Width × Height): 62 mm × 62 mm × 22 mm (1.77λ0 × 1.77λ0 × 0.63λ0)
(Fouany et al., 2017)	8-8.4 GHZ (400 MHz)	8-8.4 GHZ (400 MHz)	No	5 dBi	(Length × Width × Height): 100 mm × 100 mm × 15 mm (2.74λ0 × 2.74λ0 × 0.41λ0)
(Genovesi & Dicandia, 2022)	6.8-8.9 GHz (2.1 GHz)	7-8.15 GHz (1.15 GHz)	No	8.6 dBi	Diameter: 50 mm (1.3λ0) Height: 5.25 mm (0.137λ0)
(El Khamlichi et al., 2021)	9.4-10.5 GHz (1.1 GHz)	Not Circularly Polarized	No	9 dBi	(Length × Width × Height): 59 mm × 14 mm × 0.76 mm (1.96λ0 × 0.46λ0 × 0.025λ0)
(Anim et al., 2021)	9.01-10.2 GHz (1.19 GHz)	Not Circularly Polarized	No	8 dBi	(Length × Width × Height): 14 mm × 14 mm × 3.986 mm (0.45λ0 × 0.45λ0 × 0.126λ0)
This work	6.8-11 GHz (4.2 GHz)	7 GHz-10 GHz (3 GHz)	Yes	6.8 dBi	(Length × Width × Height): 19.7 mm × 23 mm × 0.508 mm (0.55λ0 × 0.65λ0 × 0.014λ0)

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Data availability statement

The data that support the findings of this study are available from the corresponding author, Mostafa Mahmoud Rabie, upon reasonable request.