Practical issues in microwave raster scanning

We discuss a number of practical issues in measurements with the recently proposed microwave raster scanning setup for near-field imaging of tissue. We consider the uncertainties in the measurements of phantoms emulating biological tissues. We discuss improvements in the design of sensors tailored for this application. We evaluate the performance of a tissue sensing sensor in terms of a parameter called coupling efficiency. We show that sensors with better coupling efficiency lead to significant improvement of the dynamic range of the imaging system. This is confirmed with an example of detecting a relatively small tumour simulant.