Considerations for Selecting the Right 5G-Rejection Bandpass Filter

One simple and effective solution to enable the co-existence of 5G services and Fixed Satellite Service (FSS) receiving earth stations (ES) within the same geographical area is to retrofit the FSS earth station with a microwave bandpass filter (BPF) at the receiving frontend. Choosing the right BPF can help suppress the 5G interfering signals with the least impact on in-band FSS traffic, so that 5G network can be deployed with minimal restrictions.There are multiple parameters to consider in designing the BPFs for each country. The fundamental issue is that the theory of 5G filter design must follow the law of physics which would not change from one design house to another. The key lies in the design parameters trade-offs. The BPFs provided by AsiaSat are specially designed by our technical team working closely with the experts from both the manufacturers and the broadcasters. The parameters considered by AsiaSat team include passband insertion loss (IL) which can translate to better link margins throughout the passband, along with other physical properties of the filter that allow for easy integration and better performance stability even under harsh environmental conditions.

In this article, we will first review some of the BPF design parameters that may help our customers select the right 5G-rejection BPF. The key specifications of a few leading BPFs in the market are set out in a table for easy comparison. We will also estimate and show the worst-case separation distances between a 5G base station and an FSS earth station. Through a comparison with other BPF models in the market, AsiaSat’s BPFs are demonstrated to be among the best performing BPFs in terms of the filter electrical and physical specifications.