Benefits of ferroelectric component applications at microwaves is discussed. Experience recently gained in the high-temperature film-production technology has been used for obtaining high-quality ferroelectric tunable components. The disk made from bulk SrTiO3 single crystal covered with double-sided YBa2Cu3Y7 films was used as a high-quality TM010 mode tunable resonator. Planar structures containing thin film ferroelectric layers: planar capacitor, sandwich capacitor, coplanar line, and fin line have been studied. Modeling dielectric response of low-temperature incipient ferroelectrics (SrTiO3, KTaO3) has been applied for simulation of tunable planar structures. The quality factor of a tunable component (QFCT) is suggested to characterize the validity of the component for practical applications. The high-quality planar capacitors are pioneered for the applications. The wide frequency band fin line phase shifter has been studied and simulated. The prospects for applications of ferroelectric planar structures at room temperature is discussed.

Ferroelectric Tuning of Planar and Bulk Microwave Devices

This invention provides a phased array antenna comprising an input, a feed network electronically coupled to the input, a plurality of radiating elements, a plurality of continuously voltage tunable phase shifters for receiving signals from the feed network and providing phase shifts for the signals prior to transmitting the signals to the radiating elements, and a controller for controlling the phase shift provided by the phase shifters. The phased array antennas can be configured to produce beams that can be scanned in one dimension (one-dimensional) or two dimensions (two-dimensional) by using continuously adjustable phase shifters that are based on low cost, low loss voltage-tunable dielectric materials.

Phased array antennas incorporating voltage-tunable phase shifters

The dielectric resonator

Novel design of an integrated digital refelction-type phase shifter based on a Barium Strontium Titanate thin-film ca- pacitor is presented. Measured characteristics of the phase shifter are compared with the theoretically predicted ones. Index Terms—Ferroelectrics, microwaves, phase shifter.

Digital Reflection-Type Phase Shifter Based on a

The microwave (MW) performance of tunable stripline resonators with ferroelectric (SrTiO3 or (Ba, Sr)TiO3) planar capacitors under exposure to high voltage video pulses and MW (10 GHz) signals are studied. The resonator switching times were less than 30 nanoseconds, and these values were limited by the measurement apparatus. The dependence of film capacitance and MW loss in ferroelectric films as a function of MW signal level, and their variation during the pulse, were measured. The large signal MW dielectric constant and loss tangent varied by less than 10% with increasing MW voltage amplitude for MW field strengths up to 1 MV/m in SrTiO3 films, and 0.5 MV/m in (Ba, Sr)TiO3 films.

Response time and power handling capability of tunable microwave devices using ferroelectric films

Design of tunable Gunn diode-based active antenna module including a new type of planar dielectric resonator (PDR) tuned by a ferroelectric (FE) varactor is presented. The module is designed in such a way that the PDR acts both as a stabilizing resonator and as a radiator. Microwave properties of FE elements used for voltage-controlled oscillator (VCO) tuning are considered. The module operates at a frequency around of 17 GHz and demonstrates the radiated power of 8.8plusmn0.1 dBm over the 130-MHz tuning range and a phase-noise level of -80 dBc/Hz at 100-kHz offset. 65deg width of the radiation pattern in both the E-and H-planes corresponding to a gain of 5.1 dBi was measured. The VCO module has been tested in the regime of the frequency modulation. The output signal spectra measured and simulated for modulating bipolar voltage pulses of repetition frequency f=2 MHz are presented.

Active integrated antenna based on planar dielectric resonator with tuning ferroelectric varactor

Dielectric properties (?, tan?) of single crystal SrTiO3, (STO) films at microwave frequencies (3GHz and 10GHz) and low frequency (1MHz) were under investigation The intermodulation distortion measurements at frequency 2 GHz were carried out in microstrip resonator containing STO film planar capacitor Formulas required to choose the most suitable ferroelectric materials and to design the tunable microwave devices (filters, phiase-shifters) are derived Phase-shifter based on STO films with figure of merit 70 deg/l dB operating in the frequency range (92 - 102)GHz at T = 77 K is presented

O.Y. Buslov

Papers

Active integrated antenna based on planar dielectric resonator with tuning ferroelectric varactor

Ferroelectric films: nonlinear properties and applications in microwave devices