Tamagawa Electronics Vietnam

Sharp cut filter 850-900MHz

With the development of mobile communications technologies, operators have a requirement for combined of multiple bands and systems. They are concerned about the isolation between base station site, about the levels of spurious signals and blocking between 850Mhz and 900Mhz is high demand. This white paper illustrates the requirements on isolation between 2 band frequencies.

By sharing same telecom antenna structure, operator is using 850Mhz and 900Mhz should think how to optimize their frequency to avoid leakage signal fly form each system and make interference.

 

To do this operator should do optimization on their own network and share frequency table to another operator.

They decided separate 5-10 Mhz frequency of 850Mhz DL to UL of 900Mhz system. But the property of frequency is limited and can make sure during operating if any unwanted signal crosses each other.