COUPLING BETWEEN NEIGHBORING CPWS IN MMICS

Coupling between neighboring coplanar waveguides (CPW's) is simulated and measured. Simulation is based on two-dimensional (2-D) electromagn etic analysis and a network description, The investigations show that, in general, coupling may be neglected (lower than -30 dB) if the dist ance between the CPW's is more than twice their ground-to-ground spaci ng. However, this does not hold in the conductor-backed case with a co nnection between CPW ground and backside metal. Then, one finds sharp resonance peaks in the coupling exceeding -10 dB.