free space impedance

例句：

1. 1.The free space impedance of the antenna is critical for its performance.
   天线的自由空间阻抗对其性能至关重要。
2. 2. In wireless communication, understanding the free space impedance is essential for designing a successful system.
   在无线通信中，理解自由空间阻抗对于设计一个成功的系统至关重要。
3. 3. The design of the antenna requires consideration of the free space impedance to ensure optimal performance.
   天线的设计需要考虑到自由空间阻抗，以确保最佳性能。