Sam Sattel
Everyday App Note: How to Select the Right Antenna for Your First RF Project
Antennas are a vital component in any wireless communications system, allowing you to send electrical signals through space between a transmitter and receiver. However, choosing the right antenna is no easy feat, with considerations needing to be made for size, cost, performance and a ton of other variables. Are you already considering these variables when selecting an antenna?
- How to handle undesired magnetic fields generated by your PCB.
- How to handle objects that disrupt the Line of Sight (LOS) of your antenna.
- How to improve the radiation efficiency of your antenna.
If this is your first RF project, then you have a lot of information to consider when it comes to selecting the right antenna. This Everyday App Note from Texas Instruments packs antenna theory and practical guidelines together to make your antenna selection process a success.
Types of Antennas Covered
This app note presents several antenna types to consider that are widely used in short-range wireless communications systems, including:
PCB Antennas
These antennas offer solid performance above 868 MHz and are the most affordable solution available. However, they can be difficult to design when requiring smaller footprints and performance of 433 MHz or below.
Chip Antennas
These antennas are the generalists of the antenna family. They offer the smallest footprint available, average performance, and average cost. Chip antennas are a great solution if you need the fastest time to market for your RF project.
Whip Antenna
These antennas offer great performance, but their large size makes them difficult to fit into many wireless communications systems. They are also one of the most expensive antenna types to design and manufacture.
Parameters to Consider
Knowing about antenna types alone won’t dispel the mystery of which is the best for your RF project. There are also several general parameters that need to be considered, including:
Radiation Patterns
These patterns measure how radiation will vary around an antenna. Knowing this pattern will help you to understand the ideal orientation an antenna should be placed in to maximize coverage.
Ground Effect
It’s important to understand how the size and shape of your ground plane will affect your radiation pattern. Effective use of a ground plane can restrict RF emissions in specific planes and guide antenna direction for the highest efficiency.
Size, Cost & Performance Balance
There’s always a trade-off to be made between size, cost, and performance. For example, a board with limited space might be more effective with a small, high frequency antenna than with a low frequency antenna.
Download This App note
Ready to learn about all the different antenna types, design considerations, and parameters you need to consider for your next RF project? This app note is great for beginners and veterans alike. There’s an introduction to antenna theory for those new to RF, and plenty of practical guidelines to make your antenna selection process a success!
