here is offical project soli from google.
The radar emits RF waves which is reflected by object (hand) performing gesture in front of radar. This raw signal can be processed in different ways.(Range-doppler,frequency-time,etc). This processed data is used to train different machine learning algorithms. the same is now commercially available in smart phone
The above repository is based on the paper[https://github.com/simonwsw/deep-soli] and the dataset available.