SWRA370A September   2011  – December 2025 CC1100 , CC1101 , CC2500 , CC2510 , CC2520 , CC2530 , CC2530-RF4CE , CC2540 , CC2540T , CC2541 , CC2541-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

7.3 Error Vector Magnitude

Purpose: Transmission modulation accuracy is measured using error vector magnitude (EVM). EVM, as illustrated in Figure 7-8 and Figure 7-9, is the magnitude of the phase difference as a function of time between an ideal reference signal and the measured transmitted signal.

Error Vector Magnitude Figure 7-8 Error Vector Magnitude
EVM and Related Quantities Figure 7-9 EVM and Related Quantities

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

Test Environment: Figure 7-10 illustrates the setup for the EVM test. Figure 7-10

Error Vector Magnitude Test Setup Diagram Figure 7-10 Error Vector Magnitude Test Setup Diagram
Error Vector Magnitude Test Bench Setup Using An SMA Connector Figure 7-11 Error Vector Magnitude Test Bench Setup Using An SMA Connector
Error Vector Magnitude Test Bench Setup Using An Antenna Figure 7-12 Error Vector Magnitude Test Bench Setup Using An Antenna

Procedure:

  • Step 1: Connect the instruments as shown on Figure 7-10 and Figure 7-11, or with Figure 7-12, if using an antenna.
  • Step 2: Set the EM to modulated, continuous TX mode (with random modulated data, if applicable) through SmartRF Studio.
  • Step 3: Measure EVM with the spectrum analyzer after setting up the instrument by following the steps described in the tool's user manual. (See Appendix A for more information.)

Example: EVM measurements on ZigBee signals using a Rohde & Schwarz FSQ can be set up following the instructions in Ref. 1.

Note that not all spectrum analyzers will work on this test, they must have the capability and be configured to do EVM measurements to do so.
Table 7-5 Error Vector Magnitude Test Results
EVM (%) at ____ kbp/s Design Specification (%) Pass/Fail?
Freq 1 (MHz) Freq 2 (MHz) Freq 3 (MHz)
1
2
Test Results: