Experimental evaluation of a Software-Defined Radio through a Breast Phantom aiming at Microwave Medical Imaging

This paper presents an assessment of a low-cost apparatus aiming at a Microwave Imaging (MWI) system realization targeting women breast cancer detection. Software Defined Radio (SDR) is a programmable device with the potential to circumvent the Vector Network Analyzer usage to accomplish an MWI system, especially during the prototyping stage, once the more suitable system is not established yet. BladeRF, an SDR platform, coupled to a power amplifier and a low noise amplifier, and using two Vivaldi antennas, has been assessed in terms of the radio power ability over two different propagation media: air and a breast phantom mimicking a heterogeneous breast. It features transmitter and receiver power control to deal with different signal attenuation scenarios. The results measured over the air have shown that the bladeRF can provide up to +15 dBm output power at 1 GHz carrier frequency and close to -10 dBm at 6 GHz, and distinguish a received signal as low as -80 dBm from the Vivaldi antenna. Besides, the measured results over the breast phantom have shown a signal to noise ratio above 52 dB along with the carrier frequency increase. Thus, from the performed assessment, the bladeRF met the requirements for MWI system implementation, justifying and motivating its usage.