Title :
Performance of a K-band voltage-controlled Lange coupler using a ferroelectric tunable microstrip configuration
Author :
Subramanyam, Guru ; Miranda, F.A. ; Van Keuls, Frederick ; Romanofsky, R.R. ; Canedy, C.L. ; Ramesh, Ramaswamy
Author_Institution :
Dept. of Electr. & Comput. Eng., Dayton Univ., OH
fDate :
4/1/2000 12:00:00 AM
Abstract :
We report for the first time on the performance of a Au/Ba0.6 Sr0.4TiO3(BSTO)/MgO two-layered microstrip voltage-controlled Lange coupler (VCLC) designed for Ku- and K-band frequencies at room temperature. Tight coupling of 3 dB or higher was obtained over a frequency range of 14-19 GHz. At K-band frequencies, the coupling was voltage-controllable using the nonlinear DC electric field dependence of the relative dielectric constant of BSTO (εrBSTO). The coupling level was improved from -11.6 to -3.7 dB at 20 GHz with an applied DC electric field of 16 kV/cm. The introduction of the ferroelectric tuning layer enhances the bandwidth of the VCLC in comparison with a Lange coupler with no ferroelectric layer. This work demonstrates another advantageous application for ferroelectric thin films in passive microwave components
Keywords :
ferroelectric devices; ferroelectric thin films; microstrip couplers; tuning; 14 to 20 GHz; Au-Ba0.6Sr0.4TiO3-MgO; BSTO; K-band voltage-controlled Lange coupler; Ku-band frequencies; MgO; ferroelectric thin films; ferroelectric tunable microstrip configuration; ferroelectric tuning layer; nonlinear DC electric field dependence; passive microwave component; relative dielectric constant; Couplings; Dielectric constant; Ferroelectric materials; Frequency; Gold; K-band; Microstrip; Strontium; Temperature; Voltage;
Journal_Title :
Microwave and Guided Wave Letters, IEEE
