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

5.5 868/915 and 2440-MHz Smith Chart, SWR, Bandwidth, and Efficiency

Figure 5-25 and Figure 5-26 show the theoretical Smith chart for matching the antenna for dual-band 892 and 2440 MHz with a theoretical SWR of 1.136 and 1.052.

GUID-20211124-SS0I-RGMT-HTBW-JSSGHLCR99ZZ-low.pngFigure 5-25 Theoretical Smith Chart for Dual-Band 892-MHz Match
GUID-20211124-SS0I-8Z8W-VKQM-QLTQ59SWPFX2-low.pngFigure 5-26 Theoretical Smith Chart for Dual-Band 2440-MHz Match

Further tuning of the resonance of the antenna was needed after realizing the theoretical match. Figure 5-27 and Figure 5-28 shows the resulting impedance and SWR which at 1.083 for 892 MHz and 1.239 for 2440 MHz is less than the threshold for a good match of SWR < 2.0. Table 5-9 shows the BOM with components used to relies the matching network given in Figure 1-2.

The bandwidth of the antenna defined by SWR < 2.0 can be seen in Figure 5-28 to be 956.8-847.2 = 109.6 MHz for 892 MHz and 2611-2296 = 315 MHz for 2440 MHz.

Table 5-9 Matching Network BOM for 868/915 and 2440-MHz Dual-Band Operations
Ref. DesignatorMurata Part NumberValue
Z60LQP03TN6N8H026.8 nH
Z61

DNM

Z62LQP03TNR22H02220 nH
Z63GRM0335C1H6R2BA016.2 pF
Z64GRM0335C1H2R0BA012 nH
Figure 5-27 Smith Chart Measurement of Dual Band 868/915 MHz and 2.4 GHz
Figure 5-28 SWR Measurement of Dual Band 868/915 MHz, 2.4 GHz, and Bandwidth at SWR < 2

Figure 5-29, Figure 5-30, and Figure 5-31 shows the radiation pattern of the antenna at 868, 915 and 2440 MHz. Table 5-10 shows the TRP and efficiency for the antenna with the given matching network.

Table 5-10 TRP and Efficiency for 868/915 and 2440-MHz Dual-Band Antenna Match
Figure 43Figure 65Figure 44
Frequency868 MHz915 MHz2440 MHz
Power setting13 dBm13 dBm10 dBm
Conducted output power12.17 dBm13.23 dBm9.15 dBm
TRP9.84 dBm13.1 dBm11.98 dBm
Efficiency62.4 %97.05 %83.75 %
Figure 5-29 Radiation Pattern of the Antenna Matched for Dual-Band 868/915 and 2440-MHz Radiating with 13-dBm 868-MHz Setting
Figure 5-30 Radiation Pattern of the Antenna Matched for Dual-Band 868/915 and 2440-MHz Radiating with 13-dBm 915-MHz Setting
Figure 5-31 Radiation Pattern of the Antenna Matched for Dual-Band 868/915 and 2440-MHz Radiating with 10-dBm 2440-MHz Setting