New-Tech Europe Magazine | August 2017

(PA) linearization and a sniffer receiver for white-spacedetection. These features mean that communication platforms using wideband waveforms, or occupying noncontiguous spectrum, can now be implemented in a much smaller form factor. The high dynamic range and wide bandwidth enables SIGINT, EW, and phased-array radar operation in locations with highly congested RF spectrum. The next generation is now One hundred years of device optimization had allowed the super- het to achieve greater and greater performance, in continually smaller and lower-power platforms. Those improvements are beginning to slow, as physical limitations become real. Next-generation aerospace and defense platforms will demand a new approach to RF design, one where several square inches of an existing platform is integrated into a single device. In these devices the boundary between software and hardware is blurred, allowing for greater optimization and integration and where decreased SWaP no longer means decreased performance. David Brown is an RF system applications engineer with Analog Devices, Inc., in Greensboro, North Carolina. He joined Analog Devices in 2015 and focuses primarily on defense and aerospace applications. David graduated from NC State University in 2014 with a bachelor’s degree in electrical engineering. Wyatt Taylor is a senior RF systems engineer with Analog Devices, Inc., in Greensboro, North Carolina. He is focused on defense and aerospace radio applications, with a particular emphasis on integrated RF transceivers, small- form-factor microwave design, and software- defined radio (SDR). Formerly, Wyatt was an RF design engineer at Thales Communications Inc., and Digital Receiver Technology, Inc., in the Maryland area. Wyatt received his MSEE and BSEE from Virginia Tech.

Figure 3: Zero-IF image cancellation.

Figure 4: AD9361 and AD9371 block diagrams.

have the processor physically separated from the RF components, making a quadrature correction algorithm very difficult to implement across frequency, temperature, and bandwidth. Integrated transceivers provide SWaP solution Integrating the ZIF architecture into a monolithic transceiver device provides the path forward for next-generation systems. By having the analog and RF signal chain on a single piece of silicon, process variation will be kept to a minimum. In addition, DSPblocks can be incorporated into the transceiver, removing the boundary between the quadrature calibration algorithm and the signal chain. This approach provides both unparalleled improvements in SWaP and can also

match the super-het architecture for performance specifications. Analog Devices offers two transceivers aimed at use in the defense and aerospace markets: the AD9361 and AD9371 (Figure 4). These devices integrate the RF, analog, and digital signal chain onto a single CMOS device and include digital processing to run quadrature and carrier leakage correction in real time across all process, frequency, and temperature variations. The AD9361 focuses on medium performance specifications and very low power, such as UAV data links, handheld and man-pack communication systems, and small- form-factor SIGINT. The AD9371, optimized for very high performance specifications and medium power, has an integrated ARM microprocessor for refined calibration control, as well as an observation receiver for power amplifier

46 l New-Tech Magazine Europe