Issue link: https://iconnect007.uberflip.com/i/1534120
28 DESIGN007 MAGAZINE I APRIL 2025 nal, the composite material of the enclosure will affect the signals. For example, polycar- bonate can be very attenuative. e frequen- cies selected (especially for Wi-Fi since there are several bands available) will determine the length of the antenna—whether full, half, or quarter wave—which, along with proper impedance matching, is important for opti- mal performance. Finally, the compactness of the design depends on the application of the final product. Will it be long or short-range? GPS is a long-range receiver, capturing signals from satellites in space. In contrast, Bluetooth is a transceiver with a much shorter range. e example design shown in Figure 1 demon- strates a Bluetooth design. Other important antenna characteristics to consider include the required gain, bandwidth, and radiation pat- tern for each signal. Chip antennas are great because of their small footprint and low loss. is makes them ideal for use in mobile and higher frequency applications like GPS and 2.4 GHz standards. When considering the use of chip antennas, it's important to follow the design recommen- dations of the manufacturer. A very common problem when working with chip antennas is the assumption that the chip constitutes the entire antenna when, in fact, it needs proper ground plane dimensions to resonate prop- erly. Without a proper ground plane, range will be negatively affected for most anten- nas. is is especially true for chip antennas. RF Layout Recommendations An antenna is only part of the equation. With- out proper impedance matching and RF design practices, the antenna cannot be expected to perform optimally. It is recommended to pri- Figure 1: A section of a design with a meandering inverted F antenna for a Bluetooth radio within Xpedition. Kirsten Zima