Dissertations / Research Topic ideas in RF or microwave Engineering for Mphil/PhD [2]

Hello,

I have just started for an Mphil/phd and i've come to a problem where i can't seam to find anything RF or microwave topics that i think are interesting or something which i still could be interested for the next three year researching.

I have been interested into 60GHz ISM range but still can't seam to feel comfortable studing.

I appreciate your proposed topics and i'am very interested in your ideas thank you