## 3 Fabrication of the Proposed Antenna and Measured Results  
As shown in Figure 6, the measurement system was installed in an anechoic chamber. Around the measurement system, absorbing material was placed to reduce the edge effects and hide the horizontal supporting structure. As can be seen form Figure 6b, the vertical supporting arms for the DUT and the receiving antenna were made of a material with \(\varepsilon_{r}\approx 1\).  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Column**} & **Dipole** & **Compensation** & **Dipole** & **Compensation** \\  & **Length (mm)** & **Phase (Deg.)** & **Length (mm)** & **Phase (Deg.)** \\  & \(x\)**-Direction** & \(x\)**-Direction** & \(y\)**-Direction** & \(y\)**-Direction** \\ \hline
1 & 7.00 & 0 & 6.77 & \(-\)72 \\
2 & 7.78 & \(-\)72 & 9.82 & \(-\)168 \\
3 & 9.57 & \(-\)144 & 3.00 & 96 \\
4 & 3.80 & 144 & 5.45 & 0 \\
5 & 6.23 & 72 & 7.62 & \(-\)96 \\
6 & 7.00 & 0 & 1.24 & 168 \\
7 & 7.78 & \(-\)72 & 3.78 & 72 \\
8 & 9.57 & \(-\)144 & - & - \\
9 & 3.80 & 144 & - & - \\
10 & 6.23 & 72 & - & - \\
11 & 7.00 & 0 & - & - \\ \hline \hline \end{tabular}
\end{table}
Table 1: Dipole length and compensation phase.  
Figure 5: Photograph of a \(7\times 11\)-element reflectarray using sandwiched FSS. (**a**) Top layer: cross-dipole elements layer. (**b**) Middle layer: Modified-loop FSS.  
Figure 6: (**a**) Schematic of the reflectarray measurement system. (**b**) Photos of transmitting/receiving antennas and reflectarray under test.  
Laser location devices were used to make sure the transmitting horn antenna, receiving antenna and the reflectarray under test were in the same horizon plane. The rotating position controller and Network analyzer (Agilent E8362B) were controlled by a computer program to change the AUT position and record the scattering pattern, respectively. Both of them were connected with a computer by GP-IP cables. The transmitting antenna (Tx) and receiving antenna (Rx) were a pair of horn antennas working at 12-18 GHz. The sizes of both horn antennas were the same. The aperture and the length of the horn antennas were 6.0 \(\times\) 4.0 cm\({}^{2}\) and 15.0 cm, respectively. The distances from the reflectarray under test (RUT) to Rx and Tx were 1 m and 0.8 m, respectively. RUT and Tx/Rx had a distance of 1.2 m above the chamber ground. The transmitting horn rotated coherently with the reflective surface.  
As depicted in Figure 7, the scattering patterns of the proposed reflectarray were measured in 1-degree increments in the azimuth plane. The main beam pointed at 29\({}^{\circ}\) at both operating frequencies. Considering the material losses and the effects introduced by the fabrication accuracy and the test rig in the actual test, there was a small shift from simulation. The maximum gains were 18.9 dBi and 21.2 dBi at 12 GHz(_xoz_-plane) and 16 GHz(_yoz_-plane), respectively. During the measurement, the transmitting and receiving horns overlapped at a range of \(-\)15-15\({}^{\circ}\). Thus, the measured data in this range were not considered. All the above data demonstrate that the proposed antenna with optimal dimension performs excellently to meet the requirements of the desired application.