问题:一个管孔中布放2根以上子管时,其子管等效总外径不大于管孔内径的(...
Thursday, September 15, 2022
问题:我国有线电视系统的图像质量规定,信噪比应达到()。...
Sunday, September 11, 2022
问题:共用天线电视系统主要是解决技术上的()问题A、多副天线共同接收B、多用户分配C、多用户共用天线接收D、多用户共用一副天线接收...
Tuesday, January 10, 2023
问题:延长放大器与用户分配放大器的电路处理十分相似,但它的侧重是对()...
Thursday, September 15, 2022
问题:赤道线极化定义垂直极化矢量垂直于卫星天线波束中心的轴线,并且位于...
Saturday, September 17, 2022
Saturday, September 17, 2022
问题:何为放大器最大输出电平?放大器输出电平是否越高越好?...
Sunday, September 11, 2022
Saturday, September 17, 2022
Saturday, September 17, 2022
Sunday, September 11, 2022
Thursday, September 15, 2022
问题:卫星电视信号电磁波的传输有()和()两种类型的极化以及()和()...
Saturday, September 17, 2022
Friday, September 16, 2022
问题:模拟信号数字化需要哪几个过程?并对每个过程进行简要描述。...
Sunday, September 11, 2022
问题:放大器的作用是补偿同轴电缆对信号的损耗,及放大器的增益等于同轴电...
Sunday, September 11, 2022
Thursday, September 15, 2022
Thursday, September 15, 2022
问题:采用中频调制方式做电视频道调制器的最大好处是()...
Thursday, September 15, 2022
Friday, September 16, 2022
问题:有源光设备的电光调制中若调制信号是视频信号,则可称为()。...
Thursday, September 15, 2022