23 May 2016

Peregrine's MPAC-Doherty device demonstrated optimizing RFHIC's GaN Doherty amplifier at 3.5GHz

In booth #2129 at the IEEE's International Microwave Symposium (IMS 2016) in San Francisco (24-26 May), Peregrine Semiconductor Corp of San Diego, CA, USA – a fabless provider of radio-frequency integrated circuits (RFICs) based on silicon-on-insulator (SOI) – is demonstrating a monolithic phase and amplitude controller (MPAC)–Doherty with a gallium nitride (GaN) Doherty amplifier from RFHIC Corp of Anyang-Si, South Korea (which is exhibiting in booth #821).

Peregrine's PE46140 UltraCMOS MPAC–Doherty is being used with two RFHIC GaN devices — the IE36170WD and the IEQ3656D — in a Doherty power amplifier (PA) configuration. The demo's live measurements show how quickly and reliably the MPAC–Doherty controller can compensate for Doherty device and manufacturing variations at 3.5GHz.

"In wireless base-stations, GaN has quickly become the technology of choice for power amplifiers, especially in higher frequencies," notes RFHIC's founder & chairman D. Samuel Cho. "RFHIC's GaN-on-SiC (silicon carbide) power transistors are well positioned to address the needs of this rapidly emerging market," he adds. "Peregrine's MPAC-Doherty products provide automated optimization of transceivers that improves Doherty PA yield and performance. These products will play a critical role in the proliferation of GaN by eliminating the need for cumbersome and intensive manual tuning."

While widely used in the wireless infrastructure industry, Doherty amplifiers require a considerable engineering investment to manually implement and optimize. Any mismatch or misalignment in phase and amplitude between the Doherty architecture's carrier and peaking paths can quickly contribute to higher costs and degradation of the system's overall performance. Even after optimizing with discrete components, the system remains inflexible to manufacturing variances from power amplifier assemblies. Peregrine says that its MPAC–Doherty products eliminate the need for discrete components and enable phase and amplitude control through a digital interface.

"MPAC–Doherty devices eliminate the headaches and frustrations in Doherty PA optimization," says Peregrine's director of marketing Kinana Hussain. "As more applications demand phase and amplitude precision, Peregrine's MPAC product family offers a reliable, consistent and high-performance solution."

With a frequency range extending over 3.4-3.8GHz, the UltraCMOS PE46140 is suitable for optimizing GaN-based Doherty PAs. The controller integrates a 90° RF splitter, digital phase shifters, a digital step attenuator and a digital serial peripheral interface (SPI) on a single monolithic die. In Doherty amplifier architectures, the PE46140 reduces the bill of materials (BoM) by improving the overall yield of expensive Doherty power amplifier assemblies utilizing high-efficiency GaN transistors, it is claimed. Additionally, the controller offers performance advantages in power-added efficiency (PAE), linearity across the frequency range, Doherty bandwidth through better matching and increased effectiveness of the digital pre-distortion (DPD) loop. The maximum tuning flexibility enables uniformity and repeatability between transceiver paths, while increasing system reliability. The monolithic controller can be programmed remotely through the digital interface to accommodate varying field requirements. This flexibility allows engineers to adjust the phase and amplitude in real-time for operational and environmental factors.

The RFHIC IEQ3656D and the IE36170WD are symmetrical Doherty GaN high-electron-mobility transistor (HEMT) devices. The IEQ3656D has an operating frequency of 3.4-3.8GHz, while the IE36170WD supports a frequency range of 3.52-3.56GHz. Offered in a DFN package, the IEQ3656D delivers saturated output power (PSAT) of 56W at 48V operation. The IE36170WD provides PSAT of 170W at 48V operation.

See related items:

Peregrine extends MPAC–Doherty product family to 1.8-3.8GHz to support GaN power amplifier frequencies

Peregrine makes available first UltraCMOS monolithic phase and amplitude controller

Tags: Peregrine CMOS SOI RFHIC

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Visit: www.rfhic.com