Tunable Bandstop Resonator and Filter on Si-Substrate with PST Thin Film by Sol-Gel Deposition

Abstract

Tunable bandstop resonators and filters are fabricated and measured. Lead strontium titanate (PST-Pb 0.4 Sr 0.6 (Ti 1-x Mn x )O 3 ) thin film on a high-resistivity Si substrate is used for an application of low loss tunable circuits at microwave frequency band. Parallel plated PST varactors tune resonators and 3-pole bandstop filters which resonate at the center frequency of 4.23 and 7.1 GHz and its maximum rejection is more than 13.8 dB at the stop band while the insertion loss at the pass band is less than 3 dB.

Microstrip cross-coupled stepped-impedance line bandstop filter

“…7 shows the photograph of the fabricated filter. Two ferroelectric thin film varactors fabricated using Lead-Strontium-Titanate (PST) materials [8] are implemented in the optimum location for electronically tuning. The experimental results, obtained using Agilent 8510B network analyzer, are plotted in Fig.…”

Polymer‐based route to ferroelectric lead strontium titanate thin films

“…Because of their high values of ferroelectric polarization, piezoelectric coefficient, and dielectric permittivity ferroelectric films with perovskite structure like lead zirconate titanate (PbZr x Ti 1‐x O 3 , PZT), lead strontium titanate (Pb x Sr 1‐x TiO 3 , PST), and barium strontium titanate (Ba x Sr 1‐x TiO 3 , BST) films are widely used in the fields of sensors, energy harvesting, capacitors, and FeRAMs technology . PST and BST films can be used for tunable microwave device components, such as phase shifters, filters, varactors, and delay lines . PST thin films are promising candidates for these specific applications as PST thin films show lower loss tangent, larger tunability, and lower processing temperatures than BST thin films.…”

Study of compositional change in the interfacial regions between lead strontium titanate/SiO2 and lead zirconate titanate/SiO2 by Auger emission spectroscopy

“…It was shown that SrO grows first epitaxially even on H-terminated Si surfaces with a sharp interface and thus provides an ionic template for the subsequent growths of perovskite SrTiO 3 [8,10,12]. We showed earlier that a functional PST layer (thickness > 300 nm) grows directly on top of SiO 2 [13] and that a very thin PST film (thickness < 50 nm) can serve as a barrier layer and template for the growths of PZT on top of SiO 2 [14]. However, a direct comparison between the interfacial regions of PST/SiO 2 and PZT/SiO 2 is still outstanding.…”