Analysis and Introduction of Methods to Deal with the Five Challenges of Transmitter Testing

To this end, this application guide provides targeted solutions

Designed to help you meet the following five challenges:

Challenge 1: ensure compliance with complex standards and specifications

Challenge 2: comprehensive and accurate RF power measurement for complex signals

Challenge 3: find, measure, and eliminate interference, especially for spurious and transient signals

Challenge 4: find and fix EMI problems early

Challenge 5: optimize power consumption while ensuring signal quality

Challenge "1"

1.1 ensure compliance with complex standards and codes

Both mobile data and voice services continue to require greater channel capacity

The same is often true for wireless LANs

While developers introduce various technologies to meet these needs

Each technology brings more challenges to transmitter testing

When setting up the analyzer for consistency measurement

This has also become a challenge for the analyzer!

1.2 measurement of general and special standards

Around major wireless standards

The signal analyzer can be equipped with dozens of different measurement applications

The following figure shows an example interface:

â–² the measurement software can display multiple measurements on separate screens, so as to help users understand the signal quality and characteristics more comprehensively. The LTE measurement interface includes constellation, detected positioning information, frame report and overall error report. In order to optimize and facilitate troubleshooting, different colors are set for the measurement results of different channel types.

â–² when measuring ACPR / ACLR for modern wireless systems, the specific settings are very complex. Discontinuous carrier aggregation is used in the figure, and the complexity is particularly obvious when the cumulative ACLR is included in the configuration.

â–² in the OFDM EVM multiple measurement display diagram of WLAN signal, four trace information are covered: EVM and symbol, EVM and subcarrier, constellation diagram and EVM table index

On all analyzers:

â—Ž these software adopt consistent measurement algorithms that have been verified by Shide technology in accordance with relevant standards;

â—Ž when the standard is revised and expanded, these application software will be updated synchronously;

â—Ž the algorithm and application interface are shared, so it is easy for users to get familiar with and start, which can effectively reduce the training and programming time.

Challenge "2"

Comprehensive and accurate RF power measurement for complex signals

At all stages of development and production

Accurate power measurement is very important

Choose the right tool: signal analyzer!

For high-level independent signals

The power accuracy of signal analyzer is inferior to that of power meter

However, the analyzer has more advantages in RF transmitter testing

When measuring the power of the wireless system:

The signal analyzer can effectively reduce the broadband noise power (background noise), so as to improve the measurement accuracy and dynamic range, especially for small signals or signals close to background noise.

In terms of measurement of power over time:

Reveal the dynamic power characteristics of the channel during signal burst, or reveal the dynamic power characteristics of the signal frame.

Challenge "3"

Find, measure and eliminate interference, especially for spurious and transient signals

It is very important to fully understand the spectrum output (including dynamic changes) of wireless transmitter. Of course, this includes the emergence of many transient signals. Because they occupy the spectrum and have pulse characteristics, the duty cycle of transient signals is sometimes very low. The asynchronous characteristics of communication and multiplexing mechanism lead to great changes in the duty cycle of interference signals, which is very troublesome.

Spectrum analyzer and signal analyzer

It is the preferred tool for detecting and measuring stray and interference signals

It has more general and powerful analysis functions

It becomes a powerful tool for measuring spurious and other interference signals

Challenge "4"

Find and fix EMI problems early

Wireless engineers should not only consider compliance with the specifications, but also ensure that their designs can coexist in a dense spectrum environment; At the same time, we can't get around the problem of EMI. In the early stage of design and design verification, it is easier to find and avoid such risks, and the cost is less.

Standardized measurement using general tools

You need one

Signal analyzer equipped with EMI measurement application software

EMI pre compatible measurement can be realized

Challenge "5"

Optimize power consumption while ensuring signal quality

Traditional mobile devices need frequent charging. In order to satisfy customers and stand out in the competition, it will involve the optimization of power management.

Grasp the trade-offs in power consumption:

Achieving reliable and efficient operation, especially at low or very low power levels, requires more engineering trade-offs and related tests. The DC power analyzer, which combines multiple DC power supplies and detailed power measurement, is a very convenient solution (figure a). This relatively new product makes it easier for us to understand the details of power consumption (Figure b).

Figure a: the DC power analyzer is conducting a dynamic power consumption analysis to understand the battery consumption and power demand in detail.

Figure B: the oscilloscope view (left) shows the dynamic current consumption of 30 milliseconds, and the digital recorder view (right) shows the dynamic current consumption of 30 seconds. Such measurements help to gain a more comprehensive understanding of the real power requirements of the equipment or subsystem.