lower-side-band upconverter

例句：

1. 1. The new device uses a lower-side-band upconverter to improve signal quality.
   这款新设备使用了下侧带通上变频器来提高信号质量。
2. 2. The engineer designed the circuit using a lower-side-band upconverter to reduce noise.
   工程师设计了电路，使用下侧带通上变频器来减少噪声。
3. 3. The low-side band upconverter is essential for transmitting high-frequency signals over long distances.
   低侧带通上变频器对于在长距离内传输高频信号至关重要。