RF Agile Transceiver: Selection Guide, Benefits & Manufacturers

RF agile transceivers offer flexibility in frequency tuning, making them essential for modern wireless systems. Understanding selection parameters, benefits, and key manufacturers can help you make the right choice.

What is an RF Agile Transceiver?

The transceiver which houses the RF front end along with a configurable digital interface to a processor/FPGA and a flexible baseband is known as an RF agile transceiver. This transceiver takes care of CFR (Crest Factor Reduction) and DPD (Digital Predistortion) to meet the PAPR (Peak to Average Power Ratio) requirement of the RF system.

“RF Agile Transceiver” is a term trademarked by Analog Devices Inc. for their transceivers designed for 3G, 4G, and 5G applications. The RF Agile transceiver supports tunable channel bandwidth and centre frequency over a wide range. It contains integrated ADCs/DACs, synthesizers, LNA, PA, duplex filter etc. It is located between the digital baseband section (FPGA/DSP) and the RF antenna and can easily be interfaced with digital baseband I/Q streams.

The figure depicts typical components in an RF agile transceiver IC. For illustration purposes, a single input and single output chain have been used in the figure.

As shown, there are two major sections in a transceiver: the transmit chain and the receive chain. The term “transceiver” has been derived from “transmitter” and “receiver.” The transmitter part converts the baseband input to an analog RF output, whereas the receiver part converts the analog RF input to a digital data output.

The transmit chain consists of an IQ interface from the baseband output, interpolation filters, DACs (Digital to Analog Converters), Digital Low pass filters, RF mixers, analog filters, a Power Amplifier (PA), RF attenuators, etc.

The receive chain consists of an LNA, RF mixers, I/Q amplifiers, Low pass filters, ADCs, Band shaping filters, etc. This receive chain also takes care of AGC (Automatic Gain Control), DC offset correction, Quadrature correction, etc.

The RF agile transceiver can usually be communicated with from a processor using the SPI interface. It supports a digital interface using CMOS/LVDS specifications. It takes a reference clock from an external crystal oscillator using a differential or single line. RF Transceivers can take either differential or single-ended input and generate differential or single-ended output.

RF transceivers support multiple transmitter and receiver chains based on the MIMO Tx/Rx configuration requirement in a 4G or 5G wireless system.

Selection Criteria

The following parameters and specifications are considered for the selection of an RF agile transceiver:

• Frequency Range: Ensure it supports the required frequency bands for your application (e.g., sub 6 GHz for 5G, mmWave, etc.).
• Bandwidth: Choose a transceiver with sufficient bandwidth to handle signal modulation and data rate requirements.
• Modulation Support: Verify compatibility with different modulation schemes (e.g., QAM, PSK, OFDM) for flexibility.
• Tuning Speed: Faster tuning capability is essential for applications like software-defined radio and cognitive radio.
• Noise Figure: Should be lower.
• Sensitivity: Should be higher.
• Power Efficiency: Should consume less power.
• Standards Supported: Should support multiple technologies such as Wi-Fi, LTE, 5G, GNSS, etc.
• Interface: Ensure compatibility with DSPs, FPGAs, and microcontrollers.
• Other Factors: Size, form factor, cost, availability, etc.

Advantages of RF Agile Transceiver

Following are some of the benefits of RF agile transceivers:

1. Supports multiple frequency bands, making it ideal for multi-standard communication.
2. Can be reconfigured for different wireless standards without hardware changes.
3. Enables dynamic spectrum access, crucial for cognitive radio and 5G applications.
4. Reduces the need for multiple RF components, saving space and cost.
5. It supports fast frequency switching which enhances performance in adaptive and real-time communication systems.

RF Agile Transceiver Manufacturers or Vendors

The following table lists vendors or manufacturers of RF Agile Transceivers.

Conclusion

RF agile transceivers enhance wireless communication efficiency. By selecting the right model and choosing a trusted manufacturer, you can optimize system performance.