Compact microstrip electronically tunable power divider with Chebyshev bandpass response

摘要

A new compact electronically tunable power divider with high-selectivity bandpass behavior is proposed. Based on the coupled-resonator topology, the size of the proposed divider can be reduced as the size of the assembled resonators shrinks. Besides, through properly varying the dc bias voltages applied to the varactors loaded onto the open-ends of each coupled-resonator, the passband frequency of the divider can, therefore, be changed. For the demonstration, a tunable microstrip filtering power divider with second-order Chebyshev bandpass response and equal power division has been designed and fabricated. The divider occupies a small circuit area of 0.27 λ by 0.06 λ. The measured results indicate that a frequency tuning range of better than 15% is achieved, while still keeping more than 20 dB isolation around the central frequency over the entire tuning range.