Author
Mike Wolfe
One of the most important infrastructure choices that an RF engineer makes when designing cell sites for a wireless network is what type of antenna to use. The engineer needs to strike a balance between network performance considerations, implementation costs and future proofing for the inevitable changes in spectrum and radio connectivity technologies such as the migration to higher order MIMO (Multiple Input Multiple Output).
Considering that the key role of the base station antenna is to provide the coverage layer of the network, and thus creating the environment for a great mobile user experience, selecting the right antenna is critical. What criteria should be utilized to narrow down the choices?
Here is a high-level checklist to guide the decision making process for antenna selection:
- Consider the frequency bands to be covered by the site and the number of radio/antenna connections per band. Evaluate potential passive intermodulation (PIM) scenarios using the CommScope PIM Band and Block calculators to determine restrictions on cross band combining.
- Evaluate candidate antennas in your preferred RF planning tool to validate that performance goals are met. LTE requires precise sculpting of the RF coverage area in order to maximize network performance. Consider design standardization across the network, to minimize the number of configurations and drive higher construction quality through installation repeatability.
- Using multi-band/multi-port antenna architectures to support at least one high band and one low band per antenna can minimize the number of antennas required and help maintain flexibility for future spectrum growth.
- Consider antennas that have remote electrical tilt (RET) for maximum flexibility, faster optimization and fewer part numbers to manage.
- Narrow antenna choices to those that have been tested dynamically for PIM in the factory, to insure long term PIM stability and minimize out-of-box failures.
By following these simple guidelines, your design cycles can be reduced and your time-to-market accelerated. For more information about antennas in LTE networks, see chapter eight in CommScope’s LTE Best Practices ebook. It is free and includes real-world advice for equipment selection, environmental practices and network installation. You can also download the free Base Station Antenna Selection for LTE Networks white paper for specific recommendations about selecting the right antennas for different LTE applications.
What are your antenna challenges? What questions do you have about modern antenna designs for mobile wireless networks?
