Planar tunable HTS microwave filter with patterned ferroelectric thin film

Abstract

included in the expression of impedance Z by implicitly calculated the R conductor by R ϭ l/A , if the thickness of the gold film is known and the quality of the probe contact is good enough. However, the thickness of the conductor may not be easily measured accurately and the contact resistance may not be negligible in some occasions. In our second method, the R conductor can be obtained by linear fit to the frequency dependence of the real part of impedance.

Novel trimming technique for tunable HTS microstrip filters

“…HTS filters are also suitable for future software-defined radio (SDR) systems. Since SDR systems require a filter with wide-range frequency tunability there has been increasing interest in tunable bandpass filters [1][2][3][4][5][6][7][8][9][10][11]. Center-frequency tuning has been widely researched, and various methods have been devised to increase the frequency range of tunable filters.…”

Analysis of conductor loss in interdigital capacitor based measurement of dielectric constant of ferroelectric thin film

“…Ferroelectric thin films are of great importance in the development of planar electrically tunable microwave devices such as filters and phase shifters [1,2]. Ferroelectric materials experience large changes in dielectric constant with an externally applied electrical field, which is needed in developing large electrically tunability.…”

“…However, the high dielectric loss of ferroelectric materials remains a problem in developing low-loss devices. The solution lies in either the improvement of material [3] or the optimization of device design [1], both of which need accurate acknowledgement of the dielectric properties of ferroelectric films. Therefore, it is important to develop a reliable, accurate, and convenient method to measure the dielectric constants of ferroelectric films.…”

“…Memory effects can be defined as shifts in the amplitude and phase of IMD components caused by changes in the modulation frequency [1]. They can be produced by electrical and thermal causes, the latter affecting mainly low modulation frequencies [2].…”

Tunable Coplanar Waveguide Microwave Devices on MOCVD-SrTiO3Thin Films

“…mechanically tuned resonant structures, ferrite based components or semiconductor-based voltage controlled electronics [3]. SrTiO 3 (STO) FE thin films associated with high temperature superconducting (HTSC) materials make a good compromise to realize electronically tunable devices [4][5][6] combining controllable dielectric properties of FE films with low loss microwave conductivity in HTSC. STO, which exhibits a perovskite structure, is suitable for epitaxial growth of the HTSC YBa 2 Cu 3 O 7−x (YBCO) material and has been widely studied to realize phase shifters and tunable filters or capacitors.…”