Thomas E Hartnett

US Patent:

6754295, Jun 22, 2004

Filed:

Apr 7, 2000

Appl. No.:

09/545375

Inventors:

Thomas Hartnett - Westford MA

Assignee:

Comrex Corporation - Devens MA

International Classification:

H04L 700

US Classification:

375356, 375355

Abstract:

In one embodiment, the invention is directed to methods and system for converting an analog signal to digital samples for transmission over a communication network, and for converting digital samples received over a communication network to an analog signal. According to one feature, the system of the invention generates encoding and decoding master clocks from local oscillators, thus enabling the system of the invention to operate in environments where reliable timing signal are not available from the communication network. According to another feature, the system of the invention adjusts the frequencies of the encoding and decoding master clocks based on a connect rate to the communication network. In a further feature, the system of the invention employs encoding and decoding buffers for buffering the digital samples between a modem or a digital network access device, and signal converters to maintain a defined time relationship between digital samples being transferred between the modem or the digital network access device and the signal converters.

US Patent:

8211356, Jul 3, 2012

Filed:

Jul 18, 2000

Appl. No.:

09/618741

Inventors:

Thomas M. Hartnett - Nashua NH, US
Joseph M. Wahl - Lexington MA, US

Assignee:

Surmet Corporation - Burlington MA

International Classification:

C04B 35/10

US Classification:

264663, 264681, 423385, 423630

Abstract:

A method of making aluminum oxynitride includes introducing a mixture having aluminum oxide and carbon into a chamber, agitating the mixture within the chamber, and heating the mixture to make aluminum oxynitride.

US Patent:

44813007, Nov 6, 1984

Filed:

Jan 13, 1984

Appl. No.:

6/570420

Inventors:

Thomas M. Hartnett - Nashua NH
Richard L. Gentilman - Acton MA
Edward A. Maguire - Ashland MA

Assignee:

Raytheon Company - Lexington MA

International Classification:

C04B 3558

US Classification:

501 98

Abstract:

A method of preparing substantially homogeneous aluminum oxynitride powder is provided comprising the steps of reacting gamma aluminum oxide with carbon in the presence of nitrogen, and breaking down the resulting powder into particles in a predetermined size range. A method of preparing a durable optically transparent body from this powder is also provided comprising the steps of forming a green body of substantially homogeneous cubic aluminum oxynitride powder and sintering said green body in a nitrogen atmosphere and in the presence of predetermined additives which enhance the sintering process. Preferred additives are boron, in elemental or compound form, and at least one additional element selected from the group of yttrium and lanthanum or compounds thereof. The sintered polycrystalline cubic aluminum oxynitride has a density greater than 99% of theoretical density, an in-line transmission of at least 50% in the 0. 3-5 micron range, and a resolving angle of 1 mrad or less.

US Patent:

46860703, Aug 11, 1987

Filed:

Oct 29, 1984

Appl. No.:

6/665463

Inventors:

Edward A. Maguire - Ashland MA
Thomas M. Hartnett - Nashua NH
Richard L. Gentilman - Acton MA

Assignee:

Raytheon Company - Lexington MA

International Classification:

C04B 3558

US Classification:

264 12

Abstract:

A method of preparing substantially homogeneous aluminum oxynitride powder is provided comprising the steps of reacting gamma aluminum oxide with carbon in the presence of nitrogen, and breaking down the resulting powder into particles in a predetermined size range. A method of preparing a durable optically transparent body from this powder is also provided comprising the steps of forming a green body of substantially homogeneous cubic aluminum oxynitride powder and sintering said green body in a nitrogen atmosphere and in the presence of predetermined additives which enhance the sintering process. Preferred additives are boron, in elemental or compound form, and at least one additional element selected from the group of yttrium and lanthanum or compounds thereof. The sintered polycrystalline cubic aluminum oxynitride has a density greater than 99% of theoretical density, an in-line transmission of at least 50% in the 0. 3-5 micron range, and a resolving angle of 1 mrad or less.

US Patent:

20230052113, Feb 16, 2023

Filed:

Aug 11, 2021

Appl. No.:

17/399510

Inventors:

- Waltham MA, US
Gerhard Sollner - Lincoln MA, US
Jason D. Adams - Medway MA, US
Poornima Varadarajan - Westford MA, US
Thomas M. Hartnett - Nashua NH, US

Assignee:

Raytheon Company - Waltham MA

International Classification:

H01P 1/22
H01P 1/203
H03H 7/01

Abstract:

Methods and apparatus for a frequency selective limiter (FSL) having a magnetic material substrate that tapers in thickness and supports a transmission line that has segments and bends. The segments, which differ in width and are substantially parallel to each other, such that each segment traverses the substrate on a constant thickness of the substrate.

US Patent:

20210221742, Jul 22, 2021

Filed:

Jun 11, 2020

Appl. No.:

16/899272

Inventors:

- Waltham MA, US
Thomas M. Hartnett - Nashua NH, US

International Classification:

C04B 35/505
C04B 35/04
G01J 1/04
G01J 1/42

Abstract:

Various embodiments disclosed relate to an optical window including an infrared light transmissive optical material. The optical material includes a first ceramic phase including a first ceramic material and a first dopant distributed therein. The optical material further includes a second ceramic phase homogenously intermixed with the first ceramic phase and comprising a second ceramic material and a second dopant distributed therein. The first dopant increases the refractive index of the first ceramic material and the second dopant decreases the refractive index of the second ceramic material. The first dopant and the second dopant are present in an amount such that a difference in a refractive index of the first ceramic phase and of the second ceramic phase is in a range of from about 0.001 to about 0.2.

US Patent:

20210139383, May 13, 2021

Filed:

Nov 12, 2019

Appl. No.:

16/680602

Inventors:

- Waltharn MA, US
Thomas M. Hartnett - Nashua NH, US
Richard Gentilman - Acton MA, US
Derrick J. Rockosi - Lynn MA, US
Jeremy Wagner - Brighton MA, US

International Classification:

C04B 37/00
C09K 11/08

Abstract:

A method of bonding includes applying a glass composition to at least a first material surface. The glass composition includes a glass powder and a solvent. The first material surface is disposed onto a second material surface. An elevated temperature is applied to the first material surface and the second material surface to form a bond between the first material surface and the second material surface. The first material surface and the second material surface are compressed under an isostatic pressure.

US Patent:

20210139773, May 13, 2021

Filed:

Nov 12, 2019

Appl. No.:

16/680594

Inventors:

- Waltham MA, US
Thomas M. Hartnett - Nashua NH, US
Richard Gentilman - Acton MA, US

International Classification:

C09K 11/77
C04B 35/44
C04B 35/64
C04B 35/626
C04B 41/00
C04B 41/50
C04B 41/87
G01T 1/202

Abstract:

A method of making a scintillator material includes forming a dried ceramic composition into a ceramic body with a garnet crystal formula (GdY)Ce(GaAl)O, where x is about 0 to about 2, y is about 0 to about 5, and z is about 0.001 to about 1.0. The ceramic body is sintered to form a sintered ceramic body. The sintered ceramic body is surrounded by a powder mixture that includes a garnet powder. The density of the sintered ceramic body is increased by applying an increased temperature and isostatic pressure to form the scintillator material.