引起互调干扰的器件介绍2（Introduction to intermodulation interference devices 2）.doc

引起互调干扰的器件介绍2（Introduction to intermodulation interference devices 2） Two cm differential loss 3.2dBm power sharing Three points differential loss, 5dBm power three points 5dB coupler through end differential loss 1.8dBm 6dB coupler through end differential loss 1.4dBm 7dB coupler through end differential loss 1.2dBm 10dB coupler through end differential loss 0.5dBm 15dB coupler through end differential loss 0.3dBm 20dB coupler through end differential loss 0.2dBm The allocation is based on the size of the coupler, such as the 5dB coupler, the coupling end output = the input -5dBm, the through end output = the input differential loss The coupler is acting exactly the opposite of the combiner. The coupler is used at the receiving end and the combiner is used for the transmitter. The coupler divides the received radio signals into several different receivers, and the combiner combines several radio signals from different transmitters to transmit them to the antenna. The coupler has 4 ports and also has 3 ports. In fact, the two in principle and structure is the same, the reason why the emergence of 3 port coupler, because in the 4 port coupler, one of the coupling end with a load, so that it becomes three port. Take the 4 port coupler as an example, each port has the following name: RF-INPUT radio frequency signal input terminal, RF-OUTPUT RF signal output end, COUPLED FORWARD forward coupling end, and COUPLED ERVERSE back coupling end. Take 15dB four port coupler as an example: The 0dBm signal is input from the RF-INPUT, and the power at each other port is: RF-OUTPUT -1.2dBm COUPLED FORWARD -15dBm COUPLED ERVERSE -35dBm The 0dBm signal is input from the RF-OUTPUT, and the power at each other port is: RF-INPUT -1.2dBm COUPLED FORWARD -35dBm COUPLED ERVERSE -15dBm The 0dBm signal is input from the COUPLED FORWARD, and the power obtained at each other port is: COUPLED ERVERSE -1.2dBm RF-INPUT -15dBm RF-OUTPUT -35dBm The 0dBm signal is input from the COUPLED ERVERSE, and