The boom in wireless commutations, started with the mobile phone in the early nineties and continuing with sensor networks, IoT, 5G has triggered a huge demand on antennas physically small enough to fit on small systems (e.g. handhelds, tags, drones, etc.). As the frequency bands used for those applications are still today below 10GHz, this means that the size of the antenna is usually much smaller than a wavelength, leading to electrically small antennas. Theoretical bounds on the performance of such small radiating devices have been developed since the middle of last century, so the design of often the art of finding the best possible compromise between size, shape and radiating performances. Moreover, we have shown that most of the usual measurement techniques cannot be used to characterize such antennas. In our research projects, we are interested in obtaining the best possible antenna for a specific applications; but we also make a step back in order to develop general design rules and appropriate measurement techniques.