Novel directive coupler with dual band behavior for GSM applications

A miniaturized directive coupler with dual band behavior is presented in this paper. It is suitable for GSM applications and demonstrates good performances in both imposed bandwidths. The physical implementation is done using lumped elements with high quality factor and micro-strip technology with low losses. This ensures good performances while maintaining the dimensions of the device as small as possible. A directivity of around 30dB is achieved for both frequencies; meanwhile the phase imbalance is smaller than one degree at the two imposed frequencies.