SWRA370A September   2011  – December 2025 CC1100 , CC1101 , CC2340R5-Q1 , CC2500 , CC2510 , CC2520 , CC2530 , CC2530-RF4CE , CC2540 , CC2540T , CC2541 , CC2541-Q1 , CC2640R2F-Q1 , CC2642R-Q1 , CC2662R-Q1 , CC2744R7-Q1 , CC2745P10-Q1 , CC2745R10-Q1 , CC2745R7-Q1

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
    1. 1.1 Acronyms
  5. 2Standards and System Requirements
    1. 2.1 Standards
    2. 2.2 Test Equipment Suppliers
    3. 2.3 Radio Certification URLs
  6. 3Test Equipment Requirements
    1. 3.1 System Setup
      1. 3.1.1 Conducted Test Systems
      2. 3.1.2 Radiated Test Systems
    2. 3.2 Initial Considerations for Testing
    3. 3.3 Testing Reminders
  7. 4Software Setup
    1. 4.1 SmartRF Studio 7
      1. 4.1.1 SmartRF Studio 7 Start-Up Window
      2. 4.1.2 SmartRF Studio 7 Modes
      3. 4.1.3 SmartRF Studio 7 Device Control Panel
      4. 4.1.4 SmartRF Studio 7 Software User Manual
    2. 4.2 SmartRF Studio 8
      1. 4.2.1 SmartRF Studio 8 Start-Up Window
      2. 4.2.2 SmartRF Studio 8 Radio Control Window
      3. 4.2.3 SmartRF Studio 8 Software User Guide
  8. 5DUT and Test Instrument Information
    1. 5.1 DUT
    2. 5.2 Test Instruments
  9. 6Clock Frequency Tuning
    1. 6.1 HF Clock Tuning Utilizing the Internal Cap Array
    2. 6.2 LF Clock Tuning
  10. 7Transmission Tests
    1. 7.1 Transmission Power
    2. 7.2 Power Spectral Density Mask
    3. 7.3 Error Vector Magnitude
    4. 7.4 Transmission Center Frequency Offset
    5. 7.5 Spurious Emissions
  11. 8Receive Testing
    1. 8.1 Receiver Sensitivity
    2. 8.2 Interference Testing
    3. 8.3 Interference Testing with RF Generator
  12.   Appendix A Offset EVM vs. EVM
  13.   B References
  14.   B Revision History

7.4 Transmission Center Frequency Offset

Purpose: To verify that the center frequency offset is within limits.

Pass Condition: See respective standards document for specifications and pass conditions.

Test Condition: Figure 7-13 shows the setup for transmission center frequency offset testing.

Transmission Center Frequency Offset Test Setup Diagram Figure 7-13 Transmission Center Frequency Offset Test Setup Diagram
Transmission Center Frequency Offset Test Bench Setup With A SMA Connector Figure 7-14 Transmission Center Frequency Offset Test Bench Setup With A SMA Connector
Transmission Center Frequency Offset Test Bench Setup With An Antenna Figure 7-15 Transmission Center Frequency Offset Test Bench Setup With An Antenna
Spectrum Analyzer Output from Transmission Center Frequency Offset Test Figure 7-16 Spectrum Analyzer Output from Transmission Center Frequency Offset Test

Procedure:

  • Step 1: Connect the instruments as shown on Figure 7-13 and Figure 7-14, or with Figure 7-15 if using an antenna.
  • Step 2: Set the EM to continuous, unmodulated TX mode through SmartRF Studio.
  • Step 3: Set the center frequency to the desired channel frequency.
  • Step 4: Measure the actual frequency on the spectrum analyzer. The difference between the actual frequency and the center frequency is the frequency offset. (Reference Figure 7-16 for an example of the results on the spectrum analyzer, the lower the RBW and VBW, the more precise the frequency measurement)
Table 7-6 Transmission Center Frequency Offset Test Results
Channel Frequency Frequency Offset Design Specification (ppm) Pass/Fail?
1
2
3
Test Results: