SWRA730 February   2022 CC1311P3 , CC1311R3 , CC1312R , CC1312R7 , CC1314R10 , CC1352P , CC1352P7 , CC1352R , CC1354P10 , CC1354R10

 

  1.   Trademarks
  2.   Acronyms
  3. 1Description of the PCB Antenna
    1. 1.1 Implementation of the PCB Meander Monopole Antenna
    2. 1.2 Matching Network
  4. 2Test Setup
    1. 2.1 Radiation Pattern
  5. 3Unmatched Results
    1. 3.1 Smith Chart – Natural Impedance without Antenna Match Components
    2. 3.2 Smith Chart – Impedance with external component Z64
      1. 3.2.1 433 MHz Unmatched
      2. 3.2.2 470 MHz Unmatched
      3. 3.2.3 490 MHz Unmatched
      4. 3.2.4 510 MHz Unmatched
      5. 3.2.5 868/915 MHz Unmatched
  6. 4Single-Band Matching and Result
    1. 4.1 433-MHz Smith chart, SWR, Bandwidth, and Efficiency
    2. 4.2 470-MHz Smith chart, SWR, Bandwidth, and Efficiency
    3. 4.3 490-MHz Smith Chart, SWR, Bandwidth, and Efficiency
    4. 4.4 510-MHz Smith Chart, SWR, Bandwidth, and Efficiency
    5. 4.5 868/915-MHz Smith Chart, SWR, Bandwidth, and Efficiency
  7. 5Dual Band Matching and Results
    1. 5.1 433-MHz and 2440-MHz Smith Chart, SWR, Bandwidth, and Efficiency
    2. 5.2 470-MHz and 2440-MHz Smith Chart, SWR, Bandwidth and Efficiency
    3. 5.3 490 MHz and 2440 MHz Smith Chart, SWR, Bandwidth and Efficiency
    4. 5.4 510-MHz and 2440-MHz Smith Chart, SWR, Bandwidth, and Efficiency
    5. 5.5 868/915 and 2440-MHz Smith Chart, SWR, Bandwidth, and Efficiency
  8. 6Summary - Bill of Materials and Results
  9. 7Conclusion
  10. 8References

7 Conclusion

The antenna in this application note can be used in two different modes: single-band operation or dual-band operation. When configured as single-band mode, users can configure the antenna through thematching network and Z64 to operate at a single ISM frequency between 433 MHz and 930 MHz. Users can configure the antenna in dual-band mode then the ISM frequency operation can be between 433–930 MHz and also 2.4 GHz. All modes of operation have shown a high transmitted radiated efficiency while maintaining a wide bandwidth.

The antenna design including the antenna matching network can easily be adapted to a specific ISM frequency with the option of single-band or dual-band operation. This is an advantage for designs that require just one PCB antenna structure to cover several bands by just changing the BOM. Even frequencies lower than 433 MHz can be supported, if the Z64 component is increased furthermore.

The dual-band mode is ideal when the radio solution works at sub-1 GHz ISM frequency and 2.4 GHz. When using the dual-band mode it is important that the 3rd harmonic of the 868 MHz (2.604 GHz) antenna is below the regulatory limits since the 2.4 GHz antenna (2.74 GHz to 2.38 GHz) will also radiate the 3rd harmonic.

TI recommends following the antenna dimensions as shown in Figure 1-1; Size of the antenna is 43 x 25 mm. The maximum gain is approximately 3 to 5 dBi, which is typical for a monopole antenna.

S11 measurements show that the center frequency is dependent on the size of the ground plane, but this is easily compensated for by adjusting the antenna length or the antenna match network.