Selected S11 Graphs of the Blade Antenna obtained via a Parameter Sweep using CST plus Polynomial Fit results.

A CST four parameter sweep simulation was performed on the “blade’ style antenna. The parameter variation is shown in Table 1 and the identification of run number and parameter values is shown in Table 2. Figure 1 shows the antenna model as captured in CST. Figure 2 shows the S11 results of all of the parameters.

Figures 3-6 show the curves with S11 values below -12.5 dB, -14.0 dB, and -15.0 dB respectively. Figures 7-12 focus on runs 47, 48, and 54. Figure 7 shows the S11 curves for these runs. Figure 8 shows the RMS error vs LST at latitude -26. Figure 9 shows the residuals for various polynomial fits at the low RMS error LST region and the high RMS error LST region. Figures 10-11 show the beam derivative plots at phi=0 and phi=90 degrees respectively. Figure 12 shows the beam shapes vs frequency for phi=0 and phi=90. The equation used for fitting was

𝑇𝑇𝐴𝐴𝐴𝐴𝐴𝐴 = �𝑎𝑎𝑖𝑖(𝜈𝜈 𝜈𝜈0⁄ )𝑖𝑖−2.5𝑁𝑁−1

𝑖𝑖=0

The beam derivatives show less structure than the fourpoint antenna and the RMS errors go below 1 mK for a 5 term polynomial in the low RMS error regions. From Figure 11, the beams show less structure at the 200 MHz frequency and less side lobe tendencies as compared to the fourpoint antenna.

The blade antenna does appear to be superior to the fourpoint antenna from the standpoint of RMS error for a given number of polynomial terms.

Parameter Name Value 1 (m) Value 2 (m) Value 3 (m) Panel Length 0.450 0.475 0.500 Panel Width 0.625 0.655 0.685 Panel Gap 0.20 0.22 0.24 Panel Height 0.50 0.52

Table 1. Parameter values for the 3x3x3x2 (54 runs) simulation matrix.

Figure 1. Blade antenna model in CST.

Run Gap (m)

Height (m)

Length (m)

Width (m)

Run Gap (m)

Height (m)

Length (m)

Width (m)

1 0.020 0.500 0.450 0.625 37 0.024 0.500 0.450 0.625 2 0.020 0.500 0.450 0.655 38 0.024 0.500 0.450 0.655 3 0.020 0.500 0.450 0.685 39 0.024 0.500 0.450 0.685 4 0.020 0.500 0.475 0.625 40 0.024 0.500 0.475 0.625 5 0.020 0.500 0.475 0.655 41 0.024 0.500 0.475 0.655 6 0.020 0.500 0.475 0.685 42 0.024 0.500 0.475 0.685 7 0.020 0.500 0.500 0.625 43 0.024 0.500 0.500 0.625 8 0.020 0.500 0.500 0.655 44 0.024 0.500 0.500 0.655 9 0.020 0.500 0.500 0.685 45 0.024 0.500 0.500 0.685 10 0.020 0.520 0.450 0.625 46 0.024 0.520 0.450 0.625 11 0.020 0.520 0.450 0.655 47 0.024 0.520 0.450 0.655 12 0.020 0.520 0.450 0.685 48 0.024 0.520 0.450 0.685 13 0.020 0.520 0.475 0.625 49 0.024 0.520 0.475 0.625 14 0.020 0.520 0.475 0.655 50 0.024 0.520 0.475 0.655 15 0.020 0.520 0.475 0.685 51 0.024 0.520 0.475 0.685 16 0.020 0.520 0.500 0.625 52 0.024 0.520 0.500 0.625 17 0.020 0.520 0.500 0.655 53 0.024 0.520 0.500 0.655 18 0.020 0.520 0.500 0.685 54 0.024 0.520 0.500 0.685 19 0.022 0.500 0.450 0.625 20 0.022 0.500 0.450 0.655 21 0.022 0.500 0.450 0.685 22 0.022 0.500 0.475 0.625 23 0.022 0.500 0.475 0.655 24 0.022 0.500 0.475 0.685 25 0.022 0.500 0.500 0.625 26 0.022 0.500 0.500 0.655 27 0.022 0.500 0.500 0.685 28 0.022 0.520 0.450 0.625 29 0.022 0.520 0.450 0.655 30 0.022 0.520 0.450 0.685 31 0.022 0.520 0.475 0.625 32 0.022 0.520 0.475 0.655 33 0.022 0.520 0.475 0.685 34 0.022 0.520 0.500 0.625 35 0.022 0.520 0.500 0.655 36 0.022 0.520 0.500 0.685

Table 2. Run number and parameter values for the 3x3x3x2 (54 runs) simulation matrix.

Figure 2. S11 curves of all 54 Variations. The three bundles at the far left of the graph are due to the panel length varying from 0.45 m to 0.50 m. Other bundles near the center frequency are mostly due to panel width variations.

Figure 3. Runs whose S11 doesn’t exceed a maximum of -12.5 dB.

Figure 4. Runs whose S11 doesn’t exceed a maximum of ~-14.0 dB. Run 54 is kept from the previous grouping.

Figure 5. Runs whose S11 doesn’t exceed a maximum of ~-15.0 dB. Runs 54 and 51 are kept from the previous grouping.

Figure 6. Runs whose S11 doesn’t exceed a maximum of -15.0 dB. Runs 3, 39, and 48 are highlighted to show the features of S11 smoothness (run 3), and the tradeoff between low frequency and high frequency improvement (runs 48 vs 39).

Figure 7. S11 curves for runs 47, 48, and 54.

Run 47

Run 48

Run 54

Figure 8. RMS error for 3 to 7 term polynomials vs LST for runs 47, 48, and 54.

Run 47. LST = 4 hrs

Run 47. LST = 17.3 hrs.

Run 48. LST = 4 hrs

Run 48. LST = 17.3 hrs.

Run 54. LST = 4 hrs

Run 54. LST = 17.3 hrs.

Figure 9. Residuals and RMS errors for N=2-7 term polynomials for runs 47, 48, and 54. The column on the left is in a low RMS error region (4.0 hrs) and the column on the right is for a high LST region (17.3 hrs).

Run 47.

Run 47.

Run 48.

Run 48.

Run 54.

Run 54.

Figure 10. Beam derivatives for phi=0 degrees for runs 47, 48, and 54. The column on the right is a cut through the region theta=40 degrees.

Run 47.

Run 47.

Run 48.

Run 48.

Run 54.

Run 54. Figure 11. Beam derivatives for phi=90 degrees for runs 47, 48, and 54. The column on the right is a cut through the region theta=40 degrees.

Run 47. Phi=0

Run 47. Phi=90

Run 48. Phi=0

Run 48. Phi=90

Run 54. Phi=0

Run 54. Phi=90

Figure 12. Beam plots vs frequency for runs 47, 48, and 54. The left column is for phi=0 degrees and the right column for phi = 90 degrees.