SoC generates RF test signals and analyzes results

The Apollo MxFE software-defined signal processing SoC from Analog Devices digitizes and generates analog signals with DSP in between. Applications cover aerospace & defense, instrumentation, and wireless communications.

Digitizing high-speed signals, processing them, and creating responses typically requires separate ADCs, DACs, and DSPs or FPGAs. The Apollo MxFE system-on-chip (SoC) combines signal capture, creation, and processing into a single device surrounded by a support ecosystem. Figure 1 shows the Apollo MxFE architecture.

Introduced at the 2023 International Microwave Symposium, the Apollo MxFE AD9084 contains four 20 Gsample/sec, 16-bit ADCs and four 28 Gsample/sec DACs, while the AD9088 contains eight 12-Bit, 8 Gsample/sec RF ADCs and eight 16-Bit, 16 Gsample/sec RF DACs. Both devices contain on-chip signal processing and the software support you need to program the DSP to analyze or create RF signals for phased array radar, electronic surveillance, test and measurement, and 5G/6G. The four/eight ADC/DACs let you develop phased-array systems with 4T/4R or 8T/8R elements. Figure 2 shows an 8T/8R phased-array radar application.

An increase in data-intensive applications has boosted the need for wider bandwidths and more rapid processing and analysis of data at the network edge. The AD9084 lets you directly digitize RF signals to 10 GHz, which covers 5G FR1, Wi-Fi, Bluetooth, radar, and other wireless signals. On-chip signal processing — putting Analog Devices back in the DSP business — lets you create or analyze software-defined modulation for analog or digital RF signals without the need for external up-converters or downconverters. On-chip signal processing lets you add filters, beamformers, FFTs, and other functions. For more signal and data processing, you can add an external FPGA. Figure 3 shows Apollo operating as a spectrum analyzer at IMS 2023.

In addition to the four-channel and eight-channel SoCs, the Apollo MxFE ecosystem consists of the following products:

• A PLL/VCO synthesizer with a fundamental frequency output of up to 22 GHz, temperature stability (0.06 ps/°C), and <1 ps alignment resolution.
• A power-delivery network that includes the LTM4702 8 A µmodule regulator. It features Analog Devices’ Silent Switcher 3 technology, which combines an ultra-low noise reference with Silent Switcher architecture to achieve high efficiency with wide-band noise performance, maximizing overall Apollo MxFE ecosystem performance.
• A 10-channel synchronizer that can synchronize signals to within 5 ps, providing simultaneous sampling across multiple Apollo MxFE on the same card or across different chassis. The synchronizer also supports two-dimensional system synchronization (fanout and/or daisy chain architectures).
• Companion TxVGA and RxVGA solutions provide Apollo MxFE with +15 dB of gain and the transition from single-ended to differential on Rx as well as differential to single-ended on Tx.

Both devices contain an SPI interface and high-speed control interface (HSCI) compliant with JESD204B (20 Gb/sec)/JESD204C (232.5 Gb/sec) using 24 lanes for Rx, 24 lanes for Tx.