描述
无线发射器和接收器在概念上,可分为基频与射频两个部份。基频包含发射器的输入信号之频率范围,也包含接收器的输出信号之频率范围。基频的频宽决定了数据在系统中可流动的基本速率。基频是用来改善数据流的可靠度,并在特定的数据传输率之下,减少发射器施加在传输媒介(transmissionmedium)的负荷。因此,PCB设计基频电路时,需要大量的信号处理工程知识。发射器的射频电路能将已处理过的基频信号转换、升频至指定的频道中,并将此信号注入至传输媒体中。相反的,接收器的射频电路能自传输媒体中取得信号,并转换、降频成基频。
发射器有两个主要的PCB设计目标:第一是它们必须尽可能在消耗最少功率的情况下,发射特定的功率。第二是它们不能干扰相邻频道内的收发机之正常运作。就接收器而言,有三个主要的PCB设计目标:首先,它们必须准确地还原小信号;第二,它们必须能去除期望频道以外的干扰信号;最后一点与发射器一样,它们消耗的功率必须很小。
欧美品牌停产的“DCS系统备品备件
欧美品牌常用的“DCS系统备品备件
欧美品牌停产的,常用的“PLC”备品备件
我司产品应用于以下领域:
1,《发电厂DCS监控系统》
2,《智能平钢化炉系统制造》
3,《PLC可编程输送控制系统》
4,《DCS集散控制系统》
5,《智能型消防供水控制系统》
6,《化工厂药液恒流量计算机控制系统》
7,《电气控制系统》造纸,印染生产线,变电站综合自动化控制系列
本特利,英维思,伍德沃德,福克斯波罗、西屋、瑞恩、施耐德莫迪康、ABB、AB、西门子、摩托罗拉、GE发那科、安川、博世力士乐,ACSO,力士乐等各大品牌的DCS系统配件,机器人系统配件,大型伺服系统备件。
Dell M610 96GB Memory Kit DDR3 PC3-8500R RAM (12 X 8GB)
Dell R710 96GB Memory Kit DDR3 PC3-8500R RAM (12 X 8GB)
Dell T710 96GB Memory Kit DDR3 PC3-8500R RAM (12 X 8GB)
Dell M710 96GB Memory Kit DDR3 PC3-8500R RAM (12 X 8GB)
Dell T610 96GB Memory Kit DDR3 PC3-8500R RAM (12 X 8GB)
Dell R610 96GB Memory Kit DDR3 PC3-8500R RAM (12 X 8GB)
Dell R710 112GB Memory Kit DDR3 PC3-8500R RAM (14x8GB)
Dell M1000e 8 x M710 Dual Xeon X5650 32GB RAM 2x300GB
Dell M1000e 8 x M710 Dual Xeon X5650 64GB RAM 2x300GB
Dell M1000e 8 x M710 Dual Xeon X5650 96GB RAM 2x300GB
Dell M1000e 8 x M710 Dual Xeon X5650 144GB RAM 2x300GB
Dell M1000e 8 x M710 Dual Xeon X5650 32GB RAM 4x300GB
Dell M1000e 8 x M710 Dual Xeon X5650 64GB RAM 4x300GB
Dell M1000e 8 x M710 Dual Xeon X5650 96GB RAM 4x300GB
Dell M1000e 8 x M710 Dual Xeon X5650 144GB RAM 4x300GB
Dell M1000e 8 x M710 Dual Xeon X5650 32GB RAM 2x146GB
Dell M1000e 8 x M710 Dual Xeon X5650 64GB RAM 2x146GB
Dell M1000e 8 x M710 Dual Xeon X5650 96GB RAM 2x146GB
Dell M1000e 8 x M710 Dual Xeon X5650 144GB RAM 2x146GB
Dell M1000e 8 x M710 Dual Xeon X5650 32GB RAM 4x146GB
Dell M1000e 8 x M710 Dual Xeon X5650 64GB RAM 4x146GB
Dell M1000e 8 x M710 Dual Xeon X5650 96GB RAM 4x146GB
Dell M1000e 8 x M710 Dual Xeon X5650 144GB RAM 4x146GB
Dell M1000e 8 x M710 Dual Xeon L5640 32GB RAM 2x300GB
Dell M1000e 8 x M710 Dual Xeon L5640 64GB RAM 2x300GB
Dell M1000e 8 x M710 Dual Xeon L5640 96GB RAM 2x300GB
Dell M1000e 8 x M710 Dual Xeon L5640 144GB RAM 2x300GB
Dell M1000e 8 x M710 Dual Xeon L5640 32GB RAM 4x300GB
Dell M1000e 8 x M710 Dual Xeon L5640 64GB RAM 4x300GB
Dell M1000e 8 x M710 Dual Xeon L5640 96GB RAM 4x300GB
Dell M1000e 8 x M710 Dual Xeon L5640 144GB RAM 4x300GB
Dell M1000e 8 x M710 Dual Xeon L5640 32GB RAM 2x146GB
Dell M1000e 8 x M710 Dual Xeon L5640 64GB RAM 2x146GB
Dell M1000e 8 x M710 Dual Xeon L5640 96GB RAM 2x146GB
Dell M1000e 8 x M710 Dual Xeon L5640 144GB RAM 2x146GB
Dell M1000e 8 x M710 Dual Xeon L5640 32GB RAM 4x146GB
HP BL490 G6 Intel Xeon E5504 2.0GHZ CPU Kit 509327-B21
Dell M1000e 8 x M710 Dual Xeon L5640 64GB RAM 4x146GB
Dell M1000e 8 x M710 Dual Xeon L5640 96GB RAM 4x146GB
Dell M1000e 8 x M710 Dual Xeon L5640 144GB RAM 4x146GB
HP BL490 G6 Intel Xeon X5570 2.93GHZ CPU Kit 509319-B21
Dell M1000e 4 x M710 Dual Xeon X5650 32GB RAM 2x300GB
Dell M1000e 4 x M710 Dual Xeon X5650 64GB RAM 2x300GB
Dell M1000e 4 x M710 Dual Xeon X5650 96GB RAM 2x300GB
Dell M1000e 4 x M710 Dual Xeon X5650 144GB RAM 2x300GB
Dell M1000e 4 x M710 Dual Xeon X5650 32GB RAM 4x300GB
Dell M1000e 4 x M710 Dual Xeon X5650 64GB RAM 4x300GB
Dell M1000e 4 x M710 Dual Xeon X5650 96GB RAM 4x300GB
Dell M1000e 4 x M710 Dual Xeon X5650 144GB RAM 4x300GB
Dell M1000e 4 x M710 Dual Xeon X5650 32GB RAM 2x146GB
Dell M1000e 4 x M710 Dual Xeon X5650 64GB RAM 2x146GB
Dell M1000e 4 x M710 Dual Xeon X5650 96GB RAM 2x146GB
Dell M1000e 4 x M710 Dual Xeon X5650 144GB RAM 2x146GB
Dell M1000e 4 x M710 Dual Xeon X5650 32GB RAM 4x146GB
Dell M1000e 4 x M710 Dual Xeon X5650 64GB RAM 4x146GB
Dell M1000e 4 x M710 Dual Xeon X5650 96GB RAM 4x146GB
Dell M1000e 4 x M710 Dual Xeon X5650 144GB RAM 4x146GB
Dell M1000e 4 x M710 Dual Xeon L5640 32GB RAM 2x300GB
Dell M1000e 4 x M710 Dual Xeon L5640 64GB RAM 2x300GB
Dell M1000e 4 x M710 Dual Xeon L5640 96GB RAM 2x300GB
Dell M1000e 4 x M710 Dual Xeon L5640 144GB RAM 2x300GB
Dell M1000e 4 x M710 Dual Xeon L5640 32GB RAM 4x300GB
Dell M1000e 4 x M710 Dual Xeon L5640 64GB RAM 4x300GB
Dell M1000e 4 x M710 Dual Xeon L5640 96GB RAM 4x300GB
Dell M1000e 4 x M710 Dual Xeon L5640 144GB RAM 4x300GB
Dell M1000e 4 x M710 Dual Xeon L5640 32GB RAM 2x146GB
Dell M1000e 4 x M710 Dual Xeon L5640 64GB RAM 2x146GB
Dell M1000e 4 x M710 Dual Xeon L5640 96GB RAM 2x146GB
Dell M1000e 4 x M710 Dual Xeon L5640 144GB RAM 2x146GB
Dell M1000e 4 x M710 Dual Xeon L5640 32GB RAM 4x146GB
Dell M1000e 4 x M710 Dual Xeon L5640 64GB RAM 4x146GB
Dell M1000e 4 x M710 Dual Xeon L5640 96GB RAM 4x146GB