Each mobile phone has a large number of small antennas for communication over several GSM and WCDMA bands, for Bluetooth and WLAN, and more mobile phones are also using integrated GPS, DVB-H, etc. The number of products using wireless communication is growing from having mainly been mobile phones, WLAN routers and laptops to now also include cameras, wireless TV game controllers, mp3-players, RFID tags, etc. One of the differences of small antennas compared to large antennas is that they are much harder to model accurately with software. This is mainly due to the fact that large antennas normally are used in an open environment without any neighbouring objects to disturb the antenna function. Small antennas on the other hand are usually integrated in a chassis containing materials that absorb radiation or in different ways disturb the antenna function. In a mobile phone there are furthermore a number of antennas that all affect each other. For small antennas the most important parameter is its antenna efficiency, i.e. the parameter that directly influences how much of the transmitter power is radiated into space, or how much of the radiation incident on the antenna reach the receiver. By optimizing the antenna function to as high antenna efficiency as possible it is possible to directly influence such important parameters as coverage, battery life time and bit rate in the up and down link. In this project the possibility of miniaturizing Dielectric Resonator Antennas (DRA) is explored. DRA have certain advantage such as high radiation efficiency, simply feeding and high resistance to detuning. These characteristics are required for small antennas that are integrated into mobile phones.