Different hardware realizations of the IMEC sensing engines exist. This section details the used hardware for IMEC sensing engines, as deployed in the CREW w-iLab-t test-bed.

The IMEC sensing engine consists out of three main components: a digital processing part, an analog front end and an antenna. The following paragraphs detail these:

• The SPIDER digital board contains the IMEC DIFFS chip, which is the key component of the sensing real time signal processing (Figure 1.a). This board has two generations: version 1 and 2 respectively. All deployed prototypes for CREW use version 2. Each board has a SPIDER identification number bigger than 128. Specifically this number is derived by adding 128 to the number on the white label of the spider board. These SPIDER identification numbers are available in the test-bed documentation section, eg for the CREW Zwijnaarde w-Ilab-t test bed. An FPGA and on board SRAM allow to reconfigure the SPIDER board. Currently two configurations exist according to the connected front-end type.
• The analog front end board downconverts the signal band of interest to base-band. Two types of front-end are supported for the SPIDER v2 board (*):
  • The IMEC Scaldio-2B wide band front-end, that supports sensing between 520MHz till 6.32 GHz (Figure 1.b). Note that an appropriate antenna is needed for the selected band.
  • The commercial WARP frontend for the 2.4 GHz and 5.2 GHz ISM bands (Figure 1.c).

  (*) The SPIDER board needs to be configured properly to support one of these front-end types.

• To enable correct sensing a suitable antenna is required. For the WARP front end a WiFi antenna is typically used (Figure 2.a). For the Scaldio-2B front end a suitable antenna for the frequency band of interest is recommended. Figure 2.b shows a wide band antenna suited for a frequency range between 800 MHz till 2.5 GHz.

Figure 1 : Overview of boards for IMEC sensing engines deployted in CREW (a) SPIDER v2 digital board (b) Imec Scaldio-2B analog front-end (c) WARP analog front-end. A two Euro coin is shown to indicate the size of these boards.

Figure 2 : example antenna's (a) Wifi antenna (b) broadband antenna for 800MHz .. 2.5 GHz range