Considerations for Reconfigurable Multi-Standard Antennas for Mobile Terminals

Tomorrows mobile terminals shall be multi-standard platforms for various kinds of wireless applications. So far, nowadays mobiles consist of a combination of different separated modules e.g. for GSM, for Bluetooth, WLAN, etc.. Along with these different modules typically separated antennas are use, such as one for GSM/UMTS and another one for Bluetooth and yet another one for FM radio. Currently the design is heading towards multi-standard RF modules that combine several standards or operate on the principle of a software defined radio. Hence, an ubiquitous antenna module that can be attached to such a multi-standard module is required. However, different to the software algorithms and the integrated circuitries, an antenna is still bound to its physical size in terms of wavelength in order to operate efficiently. As the operating frequency of the applications under discussion range from approx. 100 MHz to 2.5 GHz standard antenna concepts for mobile terminals cannot be use because of the large bandwidth and the physical antenna size at low frequencies. The research presented in this paper intends to analyze basic requirements for such an antenna module to operate sufficiently and to propose an applicable concept under the typical constraints of consumer electronic applications and mass production issues.