A variable capacitor having low loss and a correspondingly high Q is provided. In addition to a substrate, the variable capacitor includes at least one substrate electrode and a substrate capacitor plate that are disposed upon the substrate and formed of a low electrical resistance material, such as HTS material or a thick metal layer. The variable capacitor also includes a bimorph member extending outwardly from the substrate and over the at least one substrate electrode. The bimorph member includes first and second layers formed of materials having different coefficients of thermal expansion. The first and second layers of the bimorph member define at least one bimorph electrode and a bimorph capacitor plate such that the establishment of a voltage differential between the substrate electrode and the bimorph electrode moves the bimorph member relative to the substrate electrode, thereby altering the interelectrode spacing as well as the distance between the capacitor plates. As such, the capacitance of the variable capacitor can be controlled based upon the relative spacing between the bimorph member and the underlying substrate. A method is also provided for micromachining or otherwise fabricating a variable capacitor having an electrode and a capacitor plate formed of a low electrical resistance material such that the resulting variable capacitor has low loss and a correspondingly high Q. The variable capacitor can therefore be employed in high frequency applications, such as required by some tunable filters.

Variable capacitor and associated fabrication method

A tunable capacitor having low loss and a corresponding high Q is provided. The tunable capacitor includes first and second substrates having first and second capacitor plates disposed, respectively, thereon. The capacitor plates may include a high temperature superconductor material. A MEMS actuator, that is either driven by electrostatic force, heat or both, operably contacts the second substrate so that once the actuator is engaged it responds by displacing the second substrate, thereby varying the capacitance between said first capacitor plate and said second capacitor plate. As such, the capacitance can be controlled based upon the relative spacing between the first and second capacitor plates. The MEMS actuator may either be operably attached to the second substrate or detached, yet supporting, the second substrate.

High frequency tunable capacitors

MEMS devices include a substrate, an anchor attached to the substrate, and a multilayer member attached to the anchor and spaced apart from the substrate. The multilayer member can have a first portion that is remote from the anchor and that curls away from the substrate and a second portion that is adjacent the anchor that contacts the substrate. Related methods are also disclosed.

MEMS device members having portions that contact a substrate and associated methods of operating

An RF lens according to the present invention embodiments collimates an RF beam by refracting the beam into a beam profile that is diffraction-limited. The lens is constructed of a lightweight mechanical arrangement of two or more materials, where the materials are arranged to form a photonic crystal structure (e.g., a series of holes defined within a parent material). The lens includes impedance matching layers, while an absorptive or apodizing mask is applied to the lens to create a specific energy profile across the lens. The impedance matching layers and apodizing mask similarly include a photonic crystal structure. The energy profile function across the lens aperture is continuous, while the derivatives of the energy distribution function are similarly continuous. This lens arrangement produces a substantial reduction in the amount of energy that is transmitted in the side-lobes of an RF system.

Radio frequency lens and method of suppressing side-lobes

An active microwave antenna device includes a two-port micropatch antenna which receives signals having a first circular polarization and transmits signals of opposite circular polarization. The device includes an integrated active circuit for amplifying and, optionally, filtering the signal. An array of such devices can be formed on a single substrate, each device being an independent active antenna, thus eliminating the need for RF or IF feed networks between the devices. Such arrays are believed to be particularly suitable for spatial power combining, rapid beam scanning, microwave imaging, frequency-polarization selective processes, and other related applications. The arrays may be either reflective or transmissive.

Active micropatch antenna device and array system

Methods and apparatus for electronically steering a radio frequency signal beam (RF) along at least one of "X" and/or "Y" coordinates with respect to the axis of the signal beam (RF) and comprising n pairs of back-to-back prisms (20, 21) formed of ferroelectric dielectric material such, for example, as BaTiO3, LiNbO3, LiTaO3, Bi12 SiO20 (BSO) and Bi12 GeO20 (BGO), means for applying voltages across terminals (A, B and C, D) of the prisms (20, 21) so as to establish separate and independent DC electric fields in the prisms (20, 21) and for varying the voltage applied across the terminals of one prism (20) relative to the voltage applied across the terminals of the other prism (21) in each of the n pairs of prisms so as to alter the incremental permittivity of one prism (20) in each of the n pairs relative to the other prism in each of the n pairs (n), thereby changing the prism refraction angles and controllably deflecting the direction of the radiated energy beam to one side or the other of the undeflected beam axis. The beam steering system is highly versatile and may be used with any type of fixed beam antenna; it may comprise a composite structure (30) including two pairs of back-to-back prisms (20, 21 and 20', 21') for steering the beam along either or both of "X" and/or "Y" coordinates; and, it may be used to steer electromagnetic beams in the millimeter wave, centimeter wave, infrared wave and optical wave regions.

Electronic beam steering methods and apparatus

Electrical power at microwave frequencies produced by solar cells or similar devices on satellite stations in space is phase modulated prior to its being beamed to earth. At the receiving station on earth, the power in the beamed signal is recovered at the modulation frequency. In the first embodiment, the microwave signal from the power originating device drives a circularly polarized antenna; the modulation is achieved by reversing the phase of the drive signals so that the polarization of the propagated wave alternates between right hand and left hand polarization at a 360 Hertz rate. On earth, the detected outputs of the receiving antennas are combined in such a manner to produce a 60 Hertz three phase power signal. In the second embodiment, the microwave signal drives two orthogonal, linearly polarized antennas; the modulation is achieved by gradually changing the phase of the microwave drive signals so that the polarization of the propagated wave rotates at a 60 Hertz rate. On earth, the detected outputs of three linear antennas, spaced at 120° angular intervals, are summed to produce a 60 Hertz three phase power signal.

Donald B. Spencer

Papers

Electronic beam steering methods and apparatus

System for transmitting power from a solar satellite to earth and subsequent conversion to a 60 Hertz three phase signal