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SIW Fashions CP X-Band Antenna, Table

The antenna was designed with the help of Version 10.0 of the High-Frequency Structure Simulator (HFSS) finite-element-method (FEM) simulation software from ANSYS. It is based on TLX-8 printed-circuit-board (PCB) material from Taconic Advanced Dielectric Div. with a relative permittivity of 2.55; a height of 1.52 mm was used for the antenna. During computer simulation and optimization, it was concluded that parameter ls affects the operating frequency of the antenna, while parameters g1 and g2 determine the quality of the CP wave. The final parameter values for the antenna are shown in the table.

SIW Fashions CP X-Band Antenna, Fig. 2Figure 2 shows the fabricated SIW antenna, where an SMA connector has been soldered to the feed port. The VSWR was measured with the assistance of a model E8363B vector network analyzer (VNA) from Agilent Technologies. Figure 3 shows the simulated and measured VSWR results, where it can be seen that the measured impedance bandwidth with VSWR less than 2.0:1 is 6.5% (from 9.04 to 9.64 GHz). A measured frequency that is higher than the simulated frequency range may be due to the tolerance error in the manufacturing process of the SIW structure.

SIW Fashions CP X-Band Antenna, Fig. 3

Figure 4 shows that the measured AR also appears a frequency shift than the simulated AR, and the AR bandwidth is 1.5%. Figure 5 delineates simultaneously right-handed-circular-polarization (RHCP) and left-handed-circular-polarization (LHCP) gains for the SIW antenna in the xz- and yz-planes at 9.2 GHz. It indicates that the SIW antenna radiates a RHCP wave with cross polarization in the boresight direction. The measured gain is 8.05 dBi in the boresight direction at 9.2 GHz.

SIW Fashions CP X-Band Antenna, Fig. 4

SIW Fashions CP X-Band Antenna, Fig. 5a

SIW Fashions CP X-Band Antenna, Fig. 5b

In summary, the SIW antenna is relatively simple and easy to fabricate. It achieves high gain at 9.2 GHz with a 6.5% impedance bandwidth and 1.5% AR bandwidth, with gain of 8.05 dBi at boresight with low cross-polarization. It is a design suitable for use in satcom systems.

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This file type includes high resolution graphics and schematics when applicable.