The UHF radio amateur band situated around 436 MHz is a very popular radio band for CubeSat Communications. This band has around 14.5 dB lower path loss compared to the popular S-band due to the lower frequency. The longer wavelength accompanied with the UHF band results in antennas that are relatively big compared to the size of a CubeSat. To communicate in this band, CubeSats are therefore equipped with linear wire antennas in dipole or turnstile configuration. Compared to patch antennas which are used to communicate in the S-band, these linear wire antennas have the downside that they need a deployment mechanism. This deployment mechanism increases the risk of failure during the mission, and subsequently asks more attention during design, integration and testing of the CubeSat. Furthermore, this system adds extra mass to the CubeSat and it takes up space that could be used by other subsystems. A novel planar antenna is proposed in this paper that obviates the need for deployment and meets most of the communication requirements for a CubeSat. To resolve the issues associated with a wire antenna requiring deployment, research was conducted to use a patch antenna to communicate in the UHF band. Conventional patch antennas that are resonant at 436 MHz proved to be too big to integrate in a CubeSat body. The planar inverted F antenna (PIFA) with it small form factor with respect to the operating frequency was identified as a suitable antenna choice for CubeSats. The electromagnetic simulation software FEKO has been used to successfully simulate a PIFA. Results indicate that the antenna is resonant at 436 MHz and fits on a 3U CubeSat body. The simulated antenna has a low profile height of only 3mm such that it still fits in a CubeSat launch POD. The radiation pattern is similar to the radiation pattern of a dipole antenna with a maximum gain of 3.72 dBi and a bandwidth of 2.82MHz is obtained. The use of such a PIFA antenna with no deployment mechanisms and with potential to be integrated as part of the CubeSat structure, promises further benefits and opportunities for future CubeSat missions.