User's Guide
Table Of Contents
- 1. WFM200 Pinout
- 2. Device Configuration
- 3. Features Description
- 4. Power Supplies
- 5. Application Schematic Recommendations
- 6. Typical Application Schematics
- 7. Layout Recommendations
- 7.1 Generic RF Layout Considerations
- 7.2 GND and RF Pads Including the Diversity Port and External Antennas
- 7.3 Module Antenna
- 7.3.1 Small Board Size Recommendations for Good RF Performance
- 7.3.2 Extended X Dimension Recommendation for Good RF Performance
- 7.3.3 Y Dimension (65 to 80 mm) Recommendation for Good RF Performance
- 7.3.4 Y Dimension (80 mm or Larger) Recommendation for Good RF Performance
- 7.3.5 WFM200 Portion One Corner Bias with 3 mm Metal Keep-Outs
- 7.3.6 Recommended Antenna Loop Trace Capacitor Values
- 7.4 WFM200 Reference Evaluation Board
- 8. Recommendations for Certification
- 9. Package Outline
- 10. Integral Antenna Loop and Keep-Out Required Dimensions
- 11. Recommended PCB Land Pattern
8.2 Certified Module Antenna
The WFM200 SiP module has also been certified and designed to operate with the integrated module antenna. When using the module
antenna, customer designs should ensure that the layout recommendations are carefully being followed as described in the previous
sections in this document. The maximum module antenna gain with an appropriate carrier board size and proper layout design is +4.7
dBi with a maximum VSWR of 2:1 across frequency band 2412-2462 MHz. The antenna total radiation efficiency is about -1 dB (=
~80%).
Customer designs which do not follow this hardware guideline may not meet Max VSWR over production part-to-part variation and/or
across the Wi-Fi frequency band of interest. The customer should configure additional backoffs within the PDS for the worst-case
VSWR achievable by the design. To reduce the probability of needing to configure such additional backoffs, use the BOM and PCB
ground antenna area sizes as discussed in Section 7.3. Module Antenna.
Certified and approved board sizes and BOM are provided in the table below.
Table 8.2. Certification Board Dimensions and BOM with Integral on-Module Antenna
Carrier PCB Dimensions Size of WFM200 Section
C_ANT [pF] C_SER [pF]
Antenna Realized
Gain Max. [dBi]
X [mm] Y [mm] X [mm] Y [mm]
100 ± 3 65 ± 3 21.5 55 0.7 1.8 +4.7
Note:
1. Using an FR-4 host board PCB with a relative permittivity of ɛ
r
= 4.4 ± 10%.
This device is certified based on the board size with the maximum antenna gain (100 mm x 65 mm overall, and 55 mm x 21.5 mm
WFM200S portion) and the two external components for the loop antenna, which have values optimized to minimize mismatch loss.
Although this board size is valid to use, the recommended board size (55 mm x 17.5 mm) with the recommend nominal component
values results in a smaller overall solution size and allows for a wider range of board size and production variations.
UG395: WFM200 Hardware Design User's Guide
Recommendations for Certification
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