Optimization of varactor tunable microstrip resonators for wireless applications

This paper presents analysis, optimization and performance of stepped varactor tunable microstrip resonator (S-VTMR) using proper circuit models. The general form of resonance conditions tuning facilities of these configurations and higher harmonics behaviour are investigated. Based on the new optimization algorithm, coupling elements stabilizing a bandwidth have been suggested. The experimental S-VTMR with series varactor circuits has been fabricated and tested demonstrating a good agreement with the circuit model predictions.