MT3812

Sub-6GHz 5G-NR RF Transceiver

Radio Frequency Integrated Circuit

Overview

Metanoia’s MT3812 is a three-band 2×2 Multiple-Input Multiple-Output (MIMO) transceiver, with a digital core which controls the transceiver and interfaces. The MT3812 supports a wide range of wireless applications like 5G Sub-6GHz Open Radio Access Network (O-RAN) Radio Units (RU), local area / medium range base station, small cell systems and customer-premises equipment (CPE).

This tri-band 2×2 5G NR transceiver is designed to interface with an I/Q baseband chip with integrated data converters and software defined modem functionality. The MT3812 can be combined with MT2812 and/or MT2814 and Radio Frequency (RF) front end modules to build compact and highly flexible 5G sub-6GHz New Radio (NR), small cells systems or CPE equipment. With most of the necessary building blocks provided by Metanoia, it is the most cost-effective and competitive solution to meet the needs of various market segments for 5G network deployment.

The MT3812 uses a direct conversion architecture for both Receive (RX) and Transmit (TX) modes. The gain setting is supported by a Radio Signal Strength Indicator (RSSI) which is reported continuously to the baseband chip. The analog baseband filters have on-chip calibration. The MT3812 supports 50 to 200 MHz bandwidth (BW) in the TX mode and 20 to 200 MHz BW in the RX mode. The MT3812 also supports 400 MHz BW in loopback mode for Digital Pre-Distortion (DPD) of the TX chain.

A Low Voltage Differential Signaling (LVDS) bus is supported for bi-directional data exchanges with the baseband. It can be used to provide a continuous stream of RF RSSI samples after the Low Noise Amplifier (LNA) in each receiver chain. This allows the receiver Automatic Gain Control (AGC) algorithm on the baseband chip to observe the wideband signal level and optimize the receiver gain for best performance. The interface allows quick updates of the transmitter and receiver gains, which enables efficient implementation of DPD and Crest Factor Reduction (CFR) algorithms.

Moreover, since many of the components like LNA, LO, filters etc. are integrated, the Bill Of Materials (BOM) for the system can be significantly reduced thereby making it possible to implement compact solutions with low cost, reduced power and using a small number of external components (e.g. external PA for additional power).

Applications

The MT3812 Sub-6GHz 5G-NR RF transceiver supports a scalable architecture which can help in building higher density applications by using multiple instances of the chip.

Target Market Segments

Sub-6GHz low density O-RAN RU market
Small Cell CPE (1T1R up to 8T8R) – standalone design that can directly connect to a 5G core network
Low and High density RU
Complete end-to-end solution for RU including power amplifier (PA), transceiver, Digital Front-End (DFE), Low-PHY and fronthaul interface as specified by O-RAN

Use Cases

>> 5G RU <= 200 MHz Application System
2×2 MIMO for TDD with a single carrier with DPD
The occupied BW is typically 200 MHz comprising one or more 5G TDD component carriers The data converters on the programmable baseband SoC operate at 491.52, 938.05, or 1966.08 MSPS and support two TX and two RX IQ streams DPD in the RU system can be supported to achieve power and performance requirements Multiple TX paths are periodically observed to track variations across temperature and environment changes
>> 5G RU < 100 MHz Application System
2×2 MIMO for TDD with two aggregated carriers without DPD
The data converters on the programmable baseband SoC support a single TX/RX IQ stream and operate at 153.6 MSPS This sample rate supports an aggregate signaling bandwidth up to 50-75 MHz DPD is not used in such wideband deployments Two baseband SoCs are connected to a single MT3812 transceiver RX signal levels for AGC are shared and the TX/RX interval timing is synchronized precisely between the two programmable baseband SoC parts
>> CPE/Small Cell Application System
4×4 MIMO for TDD with two Transceivers
4×4 MIMO for TDD 5G NR system One baseband SoC is connected to two MT3812 Transceivers Larger MIMO configurations deployment possible by synchronizing multiple groupings
>> CPE/Small Cell Application System
2×2 MIMO for FDD with two MT3812 Transceivers
2×2 MIMO for FDD 5G NR system One baseband SoC is connected to two MT3812 Transceivers One MT3812 transceiver is used for transmission, and one for reception

Specifications

Flexible Sub-6GHz 5G-NR low power RF transceiver
68-pin DR-QFN package
Receiver Features	Direct conversion Flexible analog baseband filter BW 20 MHz to 200 MHz RF BW Analog differential I/O baseband interface Low Noise and High Dynamic Range
Transmitter Features	Direct conversion with adjustable gain Flexible analog baseband filter BW 50 MHz to 200 MHz RF BW Analog differential I/O baseband interface High Linearity and Low Noise Floor
Core and Interfaces	Programmable digital core for transceiver control and calibration Auxiliary Analog-to-Digital Converter (ADC) support for calibration and external functions (voltage, temperature measurements) Low complexity hi-speed custom LVDS bus Traditional low-speed SPI bus
Flexible Frequency Generation	122.88 MHz external oscillator for frequency reference 400 MHz PA output observation RX path Tri-band sub-6 GHz 2×2 Time Division Duplex (TDD) RF transceiver Second Independent Local Oscillator (LO) for use in I/Q calibration Software configurable LO band selection