Westinghouse Electric Corporation

Northrop Grumman Systems Corporation

Robert W Weinert

Thelma J Isaacs

Donald H Watt

John D Adam

Michael M Driscoll

Peter J Chantry

Bruce R McAvoy

S Visvanathan Krishnaswamy

Thomas J Smith, Jr

John De Klerk

John M Walker

Salvador H Tallisa

A dielectric resonator encased within a pressure enclosure establishes the operating frequency of a microwave circuit. The enclosure is supplied with a pressurized gas and the pressure within the enclosure is varied as a function of the deviation of the operating frequency from a desired value. For more precise control the enclosure is preferably immersed in a cryogenic cooling system.

Dielectric resonator tunable via a change in gas pressure

This invention is a design for lateral field film bulk acoustic resonators (LF-FBAR). All electrodes in this design are located on one surface of the piezoelectric material, thereby simplifying manufacturing and improving performance. The gap between electrodes is limited to a specified dimension to maximize the efficiency of the device. Single and multi-pole devices are described. Barium magnesium fluoride and lithium niobate are specified as the piezoelectric material for high frequency applications.

Lateral field FBAR

A cell-type atomic frequency standard utilizing a miniaturized gas cell and microwave exciter along with a diode laser light source. The intensity of the diode laser light source counterbalances the penalties associated with the small gas cell. The signal produced by an oscillator is applied to a vapor within the gas cell by a miniature helix coil, or LC gap conductor, or a microstrip exciter. With the dimensions of the gas cell not exceeding one-half the wavelength of the signal, and the associated circuitry formed on a semiconductor substrate, the resulting frequency standard is reduced in size by two orders of magnitude when compared to prior art devices of comparable accuracy.

Miniaturized atomic frequency standard

A transducer with thin films of gold having a high degree of orientation on surfaces previously yielding only unoriented gold has a layer of glass over the surface of the substrate material followed by a layer of oriented gold over the layer of glass. The added layer of piezoelectric material over the layer of oriented gold provides piezoelectric material having good orientation due to the oriented gold. Addition of a top conductive electrode forms a transducer wherein the piezoelectric material has a high degree of orientation.

Method for obtaining oriented gold and piezoelectric films

A method for depositing thin films of gold having a high degree of orientation on surfaces previously yielding only unoriented gold by sputtering a layer of glass over the surface of the material followed by depositing a layer of oriented gold over the layer of glass. The additional step of depositing a layer of piezoelectric material over the layer of oriented gold is included to provide piezoelectric material having good orientation due to the oriented gold. A transducer is described having a layer of glass deposited over a material which previously provided unoriented gold followed by a layer of gold, a layer of piezoelectric material and a top conductive electrode to form a transducer wherein the piezoelectric material has a high degree of orientation.

An electroacoustic delay line apparatus is disclosed including an acoustic bulk wave generating transducer positioned at one end of a delay line, with a predetermined spacing being provided between the respective electrode elements of the transducer array, such that the acoustic energy radiation from the bulk wave transducers on the end of the delay line interfaces constructively for certain frequencies at selected positions on the sensor transducer surface of the delay line. Therefore each input signal frequency of the acoustic waves is translated into a desired position on the sensor transducer surface of the delay line. The elements of the transducer array are electrically phased such that any electrode element is phase shifted by .pi. radians relative to its nearest adjacent electrode element.

Electroacoustic delay line apparatus

Crystals or Tl.sub.3 VS.sub.4, Tl.sub.3 VSe.sub.4, Tl.sub.3 NbS.sub.4, Tl.sub.3 NbSe.sub.4, Tl.sub.3 TaS.sub.4, and Tl.sub.3 TaSe.sub.4 are disclosed which have a surface containing of normal to a zero temperature coefficient of delay direction. The crystals are used to transmit acoustic waves in surface and bulk wave devices.

Crystals having zero temperature coefficients of delay

An acoustic surface wave device is disclosed which comprises a crystal of Tl.sub.3 TaS.sub.4, Tl.sub.3 TaSe.sub.4, or mixtures thereof having at least one surface suitable for the propagation of surface waves, a surface wave generating transducer mounted on the surface, and a surface wave receiving transducer mounted on the surface positioned to receive a surface wave generated by the surface wave generating transducer. The device transmits surface waves at a low velocity and high coupling efficiency and can be used in a delay line, a filter, an FM discriminator, an oscillator, or other device.

Growing community of inventors

Monroeville, PA, United States of America

Robert W Weinert