Designed for radar systems where reduced SWaP implementation is critical, an integrated direct conversion receiver development platform has been released by Analog Devices. The AD-FMCOMMS6-EBZ, which operates across a frequency range of 400MHz-4.4GHz, supports the key L- and S-band frequency radar bands. When installed with filters, the platform operates across a frequency range of 1350-1650MHz.
The AD9652 dual ADC, the ADL5566 high-dynamic-range RF/IF dual differential amplifier and the ADL5380 quadrature demodulator, are integrated within the AD-FMCOMMS6-EBZ platform. Featuring a full direct-receive signal chain path, the platform has a bandwidth of 220MHz with a pass-band flatness of ±1.0dB. The ADL5380 demodulator, which is powered by a single 5V supply, has an RF input range of 400MHz-6GHz. Optimised for IF and DC applications, ADL5566 4.5GHz dual differential amplifier provides a gain of 16dB. According to the company, the AD9652 dual 16-bit, 310-MSPS ADC achieves the industry’s lowest noise at the highest speed, enabling target identification at a much longer range. The SNR and SFDR measured at an IF of 145 MHz are 64dB and 78dBc, respectively. Other features include power management and clock distribution with fanout.
While a super-heterodyne receiver must perform several frequency translations, Analog Devices’ platform utilises an I/Q demodulator to implement a direct conversion or zero IF architecture in which just one frequency translation is required. This reduces receiver complexity and the number of conversion stages needed, increasing performance and reducing power consumption. The architecture also adds an amplification stage to the process, which maintains the full-scale input to the ADC and eliminates image rejection issues and unwanted mixing. The need for an anti-aliasing filter is removed by the image rejection inherent to the I/Q modulation scheme. To prevent smearing, the on-board local oscillator and converter clock share the same reference signal.
Enabling connectivity to FMC platforms, the AD-FMCOMMS6-EBZ has a VITA57-compliant form factor. The platform has a small footprint, making it suitable for defence, communications, and instrumentation radar systems requiring a high level of integration and performance in a compact footprint. Example applications include early warning detection, weather surveillance and air traffic control systems.
Analog Devices offers a complete design support package for the AD-FMCOMMS6-EBZ, which includes schematics, layout files, noise analysis worksheet, FPGA HDL code, and software drivers.