In the near future, CubeSats will be deployed beyond low-Earth orbit (LEO) to perform scientific tasks in deep space. To do so, these CubeSats will need high-gain antennas (HGAs) that fit in a highly confined volume. In this article, we present an innovative, deployable Ka-band antenna that folds in a 1.5-U (10 ? 10 ? 15 cm<sup>3</sup>) stowage volume suitable for 6U (10 ? 20 ? 30 cm<sup>3</sup>)-class CubeSats. This antenna is designed for telecommunication and is compatible with NASA's deep-space network (DSN) at Ka-band frequencies (i.e., uplink: 34.2-34.7 GHz; downlink: 31.8-32.3 GHz). Calculations and measurements show that 42.0-dBi gain and 57% aperture efficiency are obtained at 32 GHz. We thoroughly describe the mechanical deployment mechanism because it is a critical component of the deployable Cube-Sat antenna. This challenging new design evolved from our previous design that only provided linear polarization and a single-frequency band.