Monolithic Ka-band phase shifter using voltage tunable BaSrTiO/sub 3/ parallel plate capacitors

Abstract

A monolithic Ka-band phase shifter circuit that employs voltage tunable BaSrTiO 3 (BST) parallel plate capacitors is presented here. The circuit is capable of continuous 0-157 phase shift at 30 GHz with an insertion loss of only 5.8 dB and return loss better than 12 dB. In addition to promising loss performance (27.1 /dB) at 30 GHz, the circuit reported here has several advantages over previously reported BST phase shifters such as moderate control voltages (20 V), room temperature operation, and compatibility with monolithic fabrication techniques.

Distributed phase shifter with pyrochlore bismuth zinc niobate thin films

“…Nevertheless, the total insertion loss is encouraging and significantly better than what was observed with BST-based phase shifters using a similar design (3 dB at 10 GHz for BST [5], [17], versus 1.8 dB at 10 GHz for BZN). Unlike BZN bulk or thick-film ceramics, BZN thin film devices maintain relatively low losses well into the microwave frequency region.…”

Ferroelectric Antenna Technology

“…The figure of merit (which provides an assessment of the quality of the phase shifter) for the X-band ferroelectric BST phase shifter was 28.7°/dB at 10 GHz. Likewise, Erker et al (24) introduced a Ka-band phase shifter based on thin film BST (parallel plate) capacitors periodically loading a transmission line. In this concept, the phase velocity of the transmission line can be controlled by changing the capacitance value via an applied dc field of the external loading capacitors.…”

Efficient Analysis of Ferroelectric Device for Microwave Propagation Characteristics

“…If the shape of the ferroelectric multilayer microstrip structure is determined, the electric field intensity by the SDM. Then, the propagation constant (β) and effective permittivity (ε eff ) and voltage within the operating frequency is calculated by (3) and the objective function is computed by (4). If the objective function is larger than the specified value, or the relative error between present and previous optimization step is smaller than the predefined tolerance, then the optimization process is terminated.…”

“…The modelling process requires optimization in order to accurately estimate the microwave parameters of multilayer microstrip lines, namely, the effective dielectric constant and the propagation constant, to ensure their precise modelling. Ferroelectric materials are used for tunable microwave device applications [1][2][3] because their dielectric constant changes by an applied electric field. Application of ferroelectric materials enables design of high tunable performance microwave devices such as tunable resonator, phase shifter, and tunable filter etc.…”