TCM-Based Bezel Antenna Design With Small Ground Clearance for Mobile Terminals

A high efficiency mobile terminal antenna with small ground clearance is presented in this paper. It consists of a chassis ground, an unbroken metal bezel, and two connecting metal strips. The theory of characteristic modes is applied to analyze the eigenmodes of the design in the frequency range of 600–3000 MHz. All the resonant modes are clearly tracked and identified. Each mode of the bezel has the even and odd states and can be illustrated by a two-slot model. The multiple modes of the bezel can be effectively excited by a simple probe. By changing the locations of the connecting strips and feeder and introducing an inductor, two fundamental modes and four higher order modes of the bezel are merged, providing sufficient bandwidth for mobile communication. The measured −6 dB bandwidths are 805–995 and 1340–2870 MHz, and the measured radiation efficiency is above 65% in both bands.