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

3.2 Smith Chart – Impedance with external component Z64

In order two extend the antenna frequency range from 868–930 MHz and 2.4 GHz to support the frequency bands at 433-MHz and 470–510-MHz bands, an additional inductor is required at location Z64. By including the extra inductance Z64, the frequency range can be extended to 433–930 MHz and 2.4 GHz with the same antenna structure; see Figure 3-2. Z64 is not needed for greater than 868 MHz operation but a 0 ohm resistor or capacitor can be used in the Z64 footprint. By changing the value of Z64, the antenna can be made to resonate at different frequencies with the same antenna structure. Frequencies lower than 868 MHz will require an inductance and for frequencies greater than 868 MHz will require a capacitance. For example, a value of 51 nH is recommended for 433 MHz operation; please refer to Table 3-1.

GUID-20220119-SS0I-PMGK-N5XN-PFQLGLXR9DNT-low.pngFigure 3-2 Schematic Symbol for Antenna showing Z64
Table 3-1 Z64 recommended component value for the sub-1 GHz ISM Frequency Bands
Frequency [MHz]Value
433MHz51 nH
470 MHz39 nH
490 MHz33 nH
510MHz27 nH
892 MHz(1)2 pF
(1) Compromise with dual-operation at both 868 MHz and 915 MHz