Enabling the Latest Evolution of Wireless Technology
High data speeds, low latency, increased capacity, and an enhanced user experience — these are just some advantages of the latest evolution of wireless technology. Advanced testing ensures 5G (and 6G) systems meet top performance standards. A sampling of key test areas include timing analysis for 5G time division duplex (TDD) networks and passive on-wafer load pull measurements for 5G applications. For a deeper dive on the latter and all things load pull, download the eBook, “A Practical Guide to Load Pull Measurements.“
Amplifier Linearity Testing
What is the Crest Factor Method?
Crest factor or the peak-to-average-power ratio (PAPR) is a single numerical value that is the ratio of a signal’s highest power level to its average power level.
High PAPR signals, such as digitally modulated signals used in OFDM systems, experience wide fluctuations in magnitude over time and are often difficult to manipulate and process efficiently. This behavior can affect an amplifier’s ability to reproduce signals accurately, leading to various challenges including non-linear operation.
Engineers can test amplifier linearity with the crest factor method, which includes the following instruments:
- An additive white Gaussian noise (AWGN) source produces a band-limited noise waveform to mimic multiple, real-world carrier signals.
- Peak power sensors measure the input and output of the amplifier.
Linear performance is verified if the crest factor of the input signal is relatively close to the crest factor of the output signal. If the output crest factor reduces significantly, then it indicates the amplifier has clipped the waveform’s highest peaks in power. This behavior points to nonlinearities in the system.
Non-linearity is further quantified by plotting complementary cumulative distribution function (CCDF) curves, which provides a statistical view of crest factor occurrence. A CCDF graph shows the percentage of time or probability (y-axis) that a signal’s crest factor is equal to or greater than a certain crest factor value (x-axis).
Application SpotLight
Passive On-wafer Load Pull Measurements for 5G Applications
Critical components in 5G systems, power amplifiers (PAs) ensure transmissions maintain high integrity during transit, amplifying lower power signals to a high enough level so receivers can decode transmissions successfully. A power amplifier’s performance goals target linearity, efficiency, and achieving both the smallest size possible and expected performance standards.
Passive on-wafer load pull measurements using automated impedance tuners such as the Nano5GTM Series can be used to optimize PA design in high-frequency 5G systems. This technique assesses amplifier linearity, efficiency, output power, and other performance metrics under varying load impedance conditions.
Must-read resourceWant to Learn More?
Want to Learn More?
Read our eBook
Read more about on-wafer load pull measurements at millimeter wave (mmWave) frequencies to support the development of 5G technologies, along with other topics spanning fundamentals to sub-THz applications, in the eBook, “A Practical Guide to Load Pull Measurements.”
With this resource, get ready to strengthen your load pull knowledge and elevate your wireless designs.