Technical Insight
Mesuro & TriQuint Make Sweet Music with 90% Efficiency RF Device
The collaboration has achieved record efficiencies with established GaAs RF Devices by using accurate harmonic tuning.
Cardiff based company Mesuro has achieved record efficiencies and are sharing results of joint work with leading device manufacturers to design harmonically tuned, near theoretically-efficient power amplifiers (PAs) with existing RF transistor technologies.
The ability to achieve near theoretical-efficiencies requires accurate harmonic tuning. Mesuro’s active tuning capability can be applied to both the source and load side of a device and allows for complete control of all in-band and out-of-band impedances.
Mesuro, in association with TriQuint Semiconductor, has now made available results showing a commercial GaAs pHEMT device achieving efficiencies in excess of 90% at P1dB in a class-B bias.
According to band-limited theory, efficiencies of above ~80% for engineered 3 harmonic content should not be possible with this type of device. However, as seen from the graph above, much higher efficiencies than this were achieved.
From the device measurements undertaken, it was clear the harmonic current levels were dependent upon both drive level and input bias. This data set could prove invaluable to Power Amplifier designers, who then have the necessary information available to them to achieve optimum design goals.
Using Mesuro’s technique to extract near theoretical best performance from the RF power transistor delivers best in class efficiency as a baseline. If desired, amplifier design enhancement techniques such as Envelope Tracking or Doherty could then be applied to provide nominal incremental amplifier efficiency improvements.
“These results continue to demonstrate the value of active harmonic load-pull techniques and how they can be applied to improve existing designs, in addition to developing new products. The next stage is to take this data and fabricate a MMIC (Monolithic Microwave IC) design in order to further show how the Mesuro solution can aid reducing design cycles and achieve ‘First-Pass’ amplifier designs”, said Richard Emsley, CEO of Mesuro.
A detailed publication titled ‘Investigation and Analysis into Device Optimization for Attaining Efficiencies In-Excess of 90% When Accounting for Higher Harmonics‘ may be found on the Mesuro website.
Emsley added, “The fundamental development process for Radio Frequency Components and devices has not changed in the last three decades – until now. By using Mesuro’s waveform engineering techniques, our customers have a 100% success rate for improving their PA efficiencies and performance.”
