Abstract: A phase shifter includes a substrate, a first electrode positioned on a surface of the substrate, a tunable dielectric layer positioned on a surface of the electrode, a microstrip positioned on a surface of the tunable dielectric layer opposite the substrate, an input for coupling a radio frequency signal to the microstrip, an output for receiving the radio frequency signal from the microstrip, and a connection for applying a control voltage to the electrode. In an alternative embodiment, a second electrode can be positioned on the surface of the substrate and separated from the first electrode to form a gap positioned under the microstrip.

Abstract: A voltage controlled oscillator includes an active element having a first connection point for connection to a voltage source and an output connection point. A tunable resonator including a first voltage tunable dielectric device is connected to an input of the active element. A first circuit branch is also connected to the active element. The first circuit branch can include a second voltage tunable dielectric device. A tuning voltage controller supplies a control voltage to the first and second voltage tunable dielectric devices to control the frequency of an oscillating voltage at the output connection point. In a reflect type voltage controlled oscillator, the first circuit branch is a bypass circuit. In a transmission type voltage controlled oscillator, the first circuit branch includes a phase shifter and is connected between the active element output connection point and the tunable resonator.

Abstract: The production of low-loss, tunable composite ceramic materials with improved breakdown strengths is disclosed. The composite materials comprise ferroelectric perovskites such as barium strontium titanate or other ferroelectric perovskites combined with other phases such as low-loss silicate materials and/or other low-loss oxides. The composite materials are produced in sheet or tape form by methods such as tape casting. The composite tapes exhibit favorable tunability, low loss and tailorable dielectric properties, and can be used in various microwave devices.

Abstract: A tunable delay line includes an input, an output, a first conductor electrically coupled to the input and the output, a ground conductor, and a voltage tunable dielectric layer positioned between the first conductor and the ground conductor. DC blocks and impedance matching sections are connected between the first conductor and the input and output. Additional layers of tunable dielectric material and additional conductors can be positioned in parallel with the voltage tunable layer.

Abstract: An electronic filter includes a substrate, a ground conductor, an input, an output, a first microstrip line positioned on the substrate and electrically coupled to the input and the output, and a first tunable dielectric varactor electrically connected between the microstrip line and the ground conductor. The input preferably includes a second microstrip line positioned on the substrate and including a portion lying parallel to the first microstrip line. The output preferable includes a third microstrip line positioned on the substrate and including a portion lying parallel to the first microstrip line. The first microstrip line includes a first end and a second end, the first end being open circuited and the varactor being connected between the second end and the ground conductor. The filter further includes a bias voltage circuit including a high impedance line, a radial stub extending from the high impedance line, and a patch connected to the high impedance line for connection to a DC source.

Abstract: This invention provides a voltage tunable filter comprising an input connection point, an output connection point, and at least one circuit branch electrically coupled to the input connection point and the output connection point and including a voltage tunable dielectric varactor electrically connected to an inductor. The voltage tunable filter can be one of a low-pass, high-pass, band-pass, or band-stop filter. The varactor can include built-in DC blocking capacitors.

Abstract: Electronically tunable dielectric materials having favorable properties are disclosed. The electronically tunable materials include an electronically tunable dielectric phase such as barium strontium titanate in combination with at least two additional metal oxide phases. The additional metal oxide phases may include, for example, oxides of Mg, Si, Ca, Zr, Ti and Al. The electronically tunable materials may be provided in bulk, thin film and thick film forms for use in devices such as phased array antennas, tunable filters and the like. The materials are useful in many applications, including the area of radio frequency engineering and design.

Abstract: A phased array antenna includes a plurality of radiating elements, a feed line assembly, a ground plane positioned between the plurality of radiating elements and the feed line assembly, with the ground plane having a plurality of openings positioned between the plurality of radiating elements and the feed line assembly, and a plurality of voltage tunable dielectric phase shifters coupled to the feed line assembly.

Abstract: A tunable dielectric structure includes a first layer of dielectric material, a second layer of dielectric material positioned adjacent to the first layer of dielectric material, with the second layer of dielectric material having a dielectric constant that is less than the dielectric constant of the first layer of dielectric material, and electrodes for applying a controllable voltage across the first dielectric material, thereby controlling a dielectric constant of the first dielectric material, wherein at least one of the electrodes is positioned between the first and second layers of dielectric material. The dielectric materials can be formed in various shapes and assembled in various orientations with respect to each other. The tunable dielectric structure is used in various devices including coaxial cables, cavity antennas, microstrip lines, coplanar lines, and waveguides.

Abstract: A tunable dielectric structure includes a first layer of dielectric material, a second layer of dielectric material positioned adjacent to the first layer of dielectric material, with the second layer of dielectric material having a dielectric constant that is less than the dielectric constant of the first layer of dielectric material, and electrodes for applying a controllable voltage across the first dielectric material, thereby controlling a dielectric constant of the first dielectric material, wherein at least one of the electrodes is positioned between the first and second layers of dielectric material. The dielectric materials can be formed in various shapes and assembled in various orientations with respect to each other. The tunable dielectric structure is used in various devices including coaxial cables, cavity antennas, microstrip lines, coplanar lines, and waveguides.

Abstract: A radio frequency electronic filter includes an input, an output, and first and second resonators coupled to the input and the output, with the first resonator including a first voltage tunable dielectric varactor and the second resonator including a second voltage tunable dielectric varactor. The resonators can include a lumped element resonator, a ceramic resonator, or a microstrip resonator. Additional voltage tunable dielectric varactors can be connected between the input and the first resonator and between the second resonator and the output. Voltage tunable dielectric varactors can also be connected between the first and second resonators.

Abstract: A voltage tunable dielectric varactor includes a substrate having a first dielectric constant and having generally a planar surface, first and second electrodes positioned on the generally planar surface of the substrate, the first and second electrodes being separated to form a first gap therebetween; a tunable dielectric layer positioned on the first and second electrodes and in the first gap, the tunable dielectric layer having a second dielectric constant greater than the first dielectric constant; and third and fourth electrodes positioned on a surface of the tunable dielectric layer opposite the first and second electrodes, the third and fourth electrodes being separated to form a second gap therebetween.

Abstract: A voltage controlled oscillator includes an active element having a first connection point for connection to a voltage source and an output connection point. A tunable resonator including a first voltage tunable dielectric device is connected to an input of the active element. A first circuit branch is also connected to the active element. The first circuit branch can include a second voltage tunable dielectric device. A tuning voltage controller supplies a control voltage to the first and second voltage tunable dielectric devices to control the frequency of an oscillating voltage at the output connection point. In a reflect type voltage controlled oscillator, the first circuit branch is a bypass circuit. In a transmission type voltage controlled oscillator, the first circuit branch includes a phase shifter and is connected between the active element output connection point and the tunable resonator.

Abstract: A voltage tunable dielectric varactor includes a substrate having a first dielectric constant and having generally a planar surface, first and second electrodes positioned on the generally planar surface of the substrate, the first and second electrodes being separated to form a first gap therebetween; a tunable dielectric layer positioned on the first and second electrodes and in the first gap, the tunable dielectric layer having a second dielectric constant greater than the first dielectric constant; and third and fourth electrodes positioned on a surface of the tunable dielectric layer opposite the first and second electrodes, the third and fourth electrodes being separated to form a second gap therebetween.

Abstract: A phased array antenna includes a plurality of radiating elements, a feed line assembly, a ground plane positioned between the plurality of radiating elements and the feed line assembly, with the ground plane having a plurality of openings positioned between the plurality of radiating elements and the feed line assembly, and a plurality of voltage tunable dielectric phase shifters coupled to the feed line assembly.

Abstract: A varactor comprising a substrate, a first conductor positioned on a surface of the substrate, a second conductor positioned on the surface of the substrate forming a gap between the first and second conductors, a tunable dielectric material positioned on the surface of the substrate and within the gap, the tunable dielectric material having a top surface, with at least a portion of said top surface being positioned above the gap opposite the surface of the substrate, and a first portion of the second conductor extending along at least a portion of the top surface of the tunable dielectric material. The second conductor can overlap or not overlap a portion of the first conductor.

Abstract: A tunable phase shifter includes a waveguide, a finline substrate positioned within the waveguide, a tunable dielectric layer positioned on the finline substrate, a first conductor positioned on the tunable dielectric layer, and a second conductor positioned on the tunable dielectric layer, with the first and second conductors being separated to form a gap. By controlling a voltage applied to the tunable dielectric material, the phase of a signal passing through the waveguide can be controlled.

Abstract: Electronically tunable thick film composites of tunable phases such as barium strontium titanate and additional dielectric oxide phases are disclosed. The composite thick films can contain multiple phases such as barium strontium titanate and MgTiO3, Mg2SiO4, CaSiO3, MgO, MgZrO3, CaTiO3, MgAl2O4, and MgSrZrTiO6. The thick films may contain further additives such as zirconnates, stannates, rare earths, niobates and tantalates, for example, CaZrO3, BaZrO3, SrZrO3, BaSnO3, CaSnO3, MgSnO3, Bi2O3/2SnO2, Nd2O3, Pr7O11, Yb2O3, Ho2O3, La2O3, MgNb2O6, SrNb2O6, BaNb2O6, MgTa2O6, BaTa2O6, and Ta2O3 to improve the electronic and microwave properties of the thick film composites. The particle size of these films may be controlled in order to optimize the electronic and microwave properties. The electronically tunable thick film composites may be made by techniques such as screen-printing or spray deposition.

Abstract: A phase shifter includes a substrate, a first electrode positioned on a surface of the substrate, a tunable dielectric layer positioned on a surface of the electrode, a microstrip positioned on a surface of the tunable dielectric layer opposite the substrate, an input for coupling a radio frequency signal to the microstrip, an output for receiving the radio frequency signal from the microstrip, and a connection for applying a control voltage to the electrode. In an alternative embodiment, a second electrode can be positioned on the surface of the substrate and separated from the first electrode to form a gap positioned under the microstrip.

Abstract: Ceramic ferroelectric composite materials comprising barium strontium titte/magnesium and oxygen-containing compound composite further doped with rare earth (lanthanide) oxides. More particularly, these inventive composites are comprised of Ba.sub.1-x Sr.sub.x TiO.sub.3 /Mg--O based compound/rare earth oxide composite, wherein x is greater than or equal to 0.0 but less than or equal to 1.0, and wherein the weight ratio of BSTO to Mg compound may range from 99.75-20 wt. % BSTO to 0.25-80 wt. % Mg compound, and wherein said rare earth oxide additive comprises less than about 10 mole percent of the composite. The rare earth oxides of the composite include all oxides of the lanthanide series elements including scandium and yttrium, as well as combinations thereof. The magnesium-based compound may be selected from the group consisting of MgO, MgZrO.sub.3, MgZrSrTiO.sub.3, MgTiO.sub.3, and MgCO.sub.3.