Bandwidth enhancement of passive filters at mm-wave frequencies using effective negative group index (NGI) structures

We introduce a novel technique of phase matching and phase compensation in resonator-based millimeter wave passive filters to broaden the bandwidth and increase the center frequency. Phase matching and compensation is implemented using effective negative group index (NGI) structures. All the important parameters of NGI structure are found using proposed analysis. The insertion loss of filter without any effective NGI effect is less than ldB and return loss is around 25dB with center frequency of 38GHz and bandwidth of 40GHz. The insertion loss of NGI enhanced filter is around 2dB and return loss is around 18dB with center frequency of 60GHz and bandwidth of 60GHz. To the best of our knowledge, the insertion loss performance is the best reported results for broadband mm-wave passive filters implemented on CMOS process using lumped circuit elements. All the simulation are performed on a 0.13/im CMOS process and we found a good agreement between analysis and simulation results.