Issue link: https://iconnect007.uberflip.com/i/1534120
30 DESIGN007 MAGAZINE I APRIL 2025 ommended to achieve the desired design parameters of TX power out- put and RX sensitivity. However, the final wireless design may work dif- ferently than it did in simulation due to unforeseen factors. at's why it's recommended to pre-screen and test line-of-sight to see if it matches the simulation. However, the simulation of the design before the prototype can catch some significant prob- lems, such as ensuring adequate return loss, insertion loss, bandwidth, and expected gain. FCC Compliance in the Details Before releasing a product to the U.S. market, all electronic devices that produce intentional or unintentional electromagnetic emissions must be tested in an FCC-certified lab for com- pliance. For the three dominant wireless stan- dards, the following regulatory requirements under Part 15 are needed for compliance. 1. GPS requires FCC Part 15.109 uninten- tional radiation testing where there is a field strength limit in each frequency range such that the field strength must be below 500 µV/m above 960 MHz. 2. Bluetooth requires FCC Part 15.109 unintentional radiation and FCC Part 15.247 for digital sequence spread spec- trum (DSSS). 3. Wi-Fi requires FCC Part 15.109 uninten- tional radiation and FCC Part 15.247 for DSSS. 4. Part 15.247 compliance prevents devices that emit intentional radiation from interfering with other nearby wireless devices. It regulates devices that use spread spectrum and digital modulation within certain bands, such as 2.4 GHz, the band most associated with Bluetooth and Wi-Fi devices. All three standards need to have the first 10 harmonics checked while radiating to make sure they are compliant in restricted bands and are within FCC radiated limits. Ensure your devices are compliant with FCC regula- tions before releasing them into the market. Benefits of Early Pre-screening FCC compliance testing and certification has a one-time payment even if the product fails the pre-screening. erefore, to ensure an efficient path to market, we recommend that you pre-screen your design prior to certifica- tion and release to market. By pre-screening your prototype, you're able to find problems early. is saves time in the prototype phase of the product and saves money, not only for the number of PCBs made but also for the poten- tial of non-compliant results from the FCC lab. Pre-screening labs can also test against the regulatory requirements of different countries to determine whether your design complies with their requirements before sending it to get licensed in those regions. is will not mean it is certified; it's only to test it for compliance before sending it to a certified lab. Design for the region it will be used in since each region may have dif- ferent bands of operation of EMI requirements. Some regions, such as Latin America, typically accept FCC documentation while other coun- tries, like Australia, prefer ETSI files submitted for review. Finally, some countries, like Japan, will not accept FCC or ETSI test reports and perform the tests in-country. For the FCC, aer your device has been certified at an accredited lab, it will get its own unique FCC ID. Any small change to the PCB or antenna of the device will require it