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High-Efficiency PAs for Massive MIMO Radio Solution

High-Efficiency PAs for Massive MIMO Radio Solution

MaxLinear and Qorvo have teamed up to create a combined solution that addresses the critical challenges for 32×32 and 64×64 massive MIMO radios – the size, weight and power consumption. This solution reduces the radio’s power, weight and volume by enabling high-efficiency power amplifiers (PAs), making massive MIMO radios more practical. Additionally, this solution saves hundreds of watts per multi-element radio in both power consumption and wasted dissipated power.

The combination of MaxLIN™ Linearization Technology and Qorvo’s GaN high efficiency power amplifier, QPD0011J Doherty power amplifier driven by QPD0006, provides breakthrough line up power efficiency of 55.14% with excellent linearized performance (ACLR < -51dBc and EVM < 3%) at 41.5dBm (14W) with 30dB of gain and operating from 3.4GHz to 3.6GHz with 2xNR100MHz carriers.

This combination increases the overall power efficiency of the radio and allows for more compact radio designs through the reduction of the size of the heat sink and relaxed thermal design. The power amplifier was tested with a full 1T/1R RF front-end reference design incorporating Qorvo’s industry-leading transmit and receive products.

The QPD0011J is an asymmetric dual-path discrete GaN on SiC HEMT in a DFN package that operates from 3.3 to 3.6 GHz. In each path is a single-stage amplifier transistor. QPD0011J can deliver an average power of 16 W in a Doherty configuration, with Doherty peak power greater than 100W.

The QPD0006 is a single-path discrete GaN on SiC HEMT in a plastic overmold DFN package that operates from 2.5 to 5.0 GHz. It is a single-stage, unmatched transistor capable of delivering P3dB of 13.5 W at +48 V. It provides excellent gain at P3dB compression of 16.5dB.

The QPD0011J and QPD0006 are combined on a single, compact reference design board delivering excellent driver and Doherty stage combined efficiency of 55% linearized with MaxLin to -51dBc ACPR and EVM 2.6%. The complete end-to-end RF transmit line up efficiency is 54%.

Additionally, the PA was demonstrated with an all Qorvo 1T/1R reference design incorporating additional predrivers and gain control. A wide bandwidth Observation path is included to provide feedback to the Digital Predistortion in MaxLIN. A full high gain receiver path, including Qorvo’s industry-leading QPB9348 dual-channel low noise amplifier (LNA) with bypass switch is included. Cascaded Receive chain noise figure (NF) is 1.37dBm in the high gain state (43dB), and 1.46dB in the low gain state (26.6dB). The reference design also includes control circuitry for bias sequencing and safe shutdown with loss of gate supply. Additionally, TX PA_enable allows TDD operation of the TX and RX lineup.

The combined 1T1R reference board, QPD0011J Doherty PA and driver PA board, and MaxLinear’s Matterhorn Transceiver provide a complete demonstration solution for 32 channel transit mMIMO applications.