50Ω impedance calculation:
If the value of D1 exceeds 3 times of W1, it has weak effect on impedance.
Figure 24. Impedance calculation for four-layer board top layer trace
6.8. Main Antenna Design
6.8.1. External Antenna
The external antenna has good performance. The antenna is placed outside the complete
machine, the antenna space is large, and the antenna performance is not easy to be
affected by the internal environment of the complete machine, so that the antenna does
not need to be independently designed for each project. The compatibility is good. Most
of the interfaces of such antennas are SMA interfaces.
Figure 25. External antenna
6. Radio Frequency
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