Abstract: The high power ferroelectric RF phase shifter contains a ferroelectric material in a microstrip line section. Between the ferroelectric phase shifter and the input, there is a ferroelectric matching transformer. Between the ferroelectric phase shifter and the output, there is a quarter wave ferroelectric matching transformer. A bias field is connected across the top and bottom surfaces of the ferroelectric material. When a bias field is applied across the ferroelectric material, the permittivity is reduced and as such the velocity of propagation is increased. This causes an increase in the effective electrical length of the phase shifter. Increasing the bias voltage increases the phase shift. The ferroelectric RF phase shifter may be constructed of a ferroelectric liquid crystal (FLC). The ferroelectric material is operated above its Curie temperature.

Abstract: The ferroelectric scanning RF antenna includes a ferroelectric material having conductors deposited thereon that are connected to an adjustable d.c. or a.c. voltage source. The scanning antenna is placed in an RF transmission line that includes appropriate input and output impedance matching devices such as quarter-wave transformers. The scanning section of the RF scanning antenna is constructed of two prismatic structures of a ferroelectric material. When the two prismatic structures are at the same zero bias voltage, then the RF energy passing through the antenna is not deflected and a boresight radiation pattern is obtained. Application of a bias voltage reduces the permittivity and the refractive index of the outer prismatic structure. The RF energy is refracted away from the normal at the interface between the prismatic surfaces and the radiation pattern is scanned in one direction. Application of a bias voltage reduces the permittivity and the refractive index of the inner prismatic structure.

Abstract: The Ferroelectric high Tc superconductor RF Phase Shifter contains a ferroelectric medium and a film of a single crystal high Tc superconductor is used as the conductors. Between the ferroelectric medium and the input, there is a quarter-wave, dielectric or ferroelectric or the same material as used for the phase shifter, matching transformer. Between the ferroelectric medium and the output, there is a quarter-wave, dielectric, ferroelectric or the same material as used for the phase shifter, matching transformer. A bias field is connected across the top and bottom surfaces of the active ferroelectric medium. When a bias field is applied across the surfaces of the ferroelectric medium, the permittivity is reduced and as such the velocity of propagation is increased. This causes an increase in the effective electrical length of the phase shifter or a phase difference or time delay. Increasing the bias voltage increases the phase shift.

Abstract: To reduce the losses, high Tc superconductive waveguide filters are disclosed. There are two approaches to make the filters. In the first approach, all waveguide sections, irises, flanges are made of a single crystal high Tc superconductor. The single crystal is machined to the desired shape and size, the pieces are brazed and connected with flanges. In the second approach all waveguide sections, irises and flanges are made of a single crystal dielectric material the conducting surfaces of which are deposited with a film of a single crystal high Tc superconductor. The waveguide sections, irises and flanges are connected together by brazing or by a similar method. There are two basic types, (1) band pass and (2) band reject, of filters. In the band pass type, a series of resonators are placed one after another with a separation, typically, of three quarters of a wavelength between the centers of adjacent resonators. In the band reject filters, the resonators are in branch lines, i.e.

Abstract: To reduce losses of commercial room temperature couplers, high Tc superconducting waveguides and waveguide flanges are used for couplers. There are two approaches for making these high Tc superconducting waveguide structures. One is to use a single crystal such as YBaCuO (YBCO), cut and machine the crystal to the desired shape, and use high Tc superconducting flanges. In the second method, a good quality dielectric, such as sapphire is used and cut and machined to the desired shape. The conducting surfaces are coated with a single crystal high Tc superconducting material such as YBCO. The waveguides are brazed together. Low loss is important particularly for high power couplers. Significant amount of RF power is lost even with a low loss coupler. The high Tc superconducting couplers will provide a significant benefit in high power RF systems handling power levels such as 0.5 megawatts.

Abstract: The ferroelectric limiter utilizes the bias voltage dependent dielectric constant property of a ferroelectric material. A main transmission line having a length of two or more half wavelengths at the operating frequency is used. A branch line is connected at one half wavelength away from one end of the transmission line. The branch line presents a very high impedance on the main transmission line at a low level of signal. The branch line contains a ferroelectric material. As the signal level increases, the dielectric constant of the ferroelectric material in the branch line changes. This reduces the impedance presented by the branch line on the main transmission line reducing the impedance of the main transmission line and the resulting output of the limiter. As the signal level increases, the impedance presented by the branch line on the main transmission line becomes increasingly smaller, further reducing the output of the of the limiter. Two designs of the limiter are presented.

Abstract: An electronically controlled ferroelectric RF switch is an active medium formed from a ferroelectric material the permittivity, and as such the refractive index, of which may be varied by varying the strength of an electric field in which it is immersed. The ferroelectric RF switch includes the ferroelectric material having electrodes or conductors mounted thereon that are connected to an adjustable d.c. or a.c. voltage source. The switch may be placed in an RF transmission line that includes appropriate input and output impedance matching devices such as quarterwave transformers. The active medium of the RF switch is constructed of two prismatic structures of a ferroelectric material. When the two prisms are at the same zero bias voltage, then the RF energy passing through the switch is not deflected and the switch is in the OFF condition. Application of a bias voltage reduces the permittivity and the refractive index of the outer prismatic structure.