Estimation of Maximum Attainable Antenna Bandwidth in Electrically Small Mobile Terminals

An estimate for the maximum attainable antenna bandwidth in electrically small mobile terminals is derived for the case that the operating band is below the chassis resonance frequency. The study is based on the double resonator model. Optimization is used to estimate the maximum bandwidth. The results are combined with numerically calculated radiation quality factors for plates of different aspect ratio to present maximum attainable bandwidth as a function of chassis length and aspect ratio