1. Five different kits are offered, such as this X-band system that operates at 9.8 GHz.Each SDR evaluation kit includes an RF module, an FPGA-based processor module, and a graphical-user-interface (GUI) (Fig. 1). The required cables, antennas, and power adapter are also included. Five different RF modules are currently offered: the SDR-RF 240B, SDR-RF 580B, SDR-RF 620B, SDR-RF 980B, and SDR-RF 2500B. These modules have operating-center frequencies of 2.45, 5.80, 6.20, 9.80, and 25.0 GHz, respectively. Ancortek offers five separate SDR kits—one for each RF module. The part numbers for the kits are SDR-KIT 240B, SDR-KIT 580B, SDR-KIT 620B, SDR-KIT 980B, and SDR-KIT 2500B. The SDR-PM 402 processor module is compatible with all RF modules, and is included in every kit.
An SDR system block diagram illustrates the RF module, processor module, and GUI (Fig. 2). In addition to the FPGA, the processor module consists of a 12-bit digital-to-analog converter (DAC) and two 12-bit analog-to-digital converters (ADCs). Because the SDR kits are intended primarily for short-range applications, a frequency-modulated-continuous-waveform (FMCW) radar-system architecture is utilized.
This architecture enables short range and velocity to be measured accurately and simultaneously. A direct-conversion homodyne receiver mixes the received signal with the transmitted FMCW signal, resulting in a signal with very low frequency—in the hundreds of kilohertz. As a result, the ADC sampling rate requirements can be eased considerably. Specifically, the DAC and ADCs operate at sampling rates of 40 Msamples/s. Continuous-wave (CW) and frequency-shift-keying (FSK) waveforms are also available with the same system architecture.
