CHERYL V LISS
Engineering in Merrimack, NH
License number
Massachusetts 18621
Issued Date
Apr 24, 1999
Type
Engineer in Training
Address
Address
Merrimack, NH 03054
Professional information
Helical Waveguide To Rectangular Waveguide Coupler
US Patent:
4851736, Jul 25, 1989
Filed:
Jun 3, 1988
Appl. No.:
7/201804
Inventors:
Robert Harper - Concord MA
Cheryl V. Liss - Merrimack NH
Cheryl V. Liss - Merrimack NH
Assignee:
Raytheon Company - Lexington MA
International Classification:
H01J 2534, H01P 508
US Classification:
315 35
Abstract:
Slow-wave structures are formed by the method of this invention in the form of helical or coupled-cavity structures. A helical waveguide form of slow-wave structure is formed of a solid rod of copper machined with a deep, narrow helical groove. A copper sleeve is brazed to the periphery of the resulting helical thread to form a helically spiraling pathway about a solid axially centered and axially extending center portion. The center portion is then totally eroded away to form a slow wave structure having a helical radially-extending portion, or if only partially eroded with an inner helical axially-extending ridge to provide a helical axially-centered gap between adjacent ridges. The helix is extended into a rectangular waveguide for coupling the slow-wave structure to the source and to the load. The coupled-cavity forms of waveguide slow-wave structures are formed by machining disks from a solid rod of copper. The disks are supported in their desired positions by an axial retained portion of the rod until the disks are brazed inside a cylindrical shell of copper.
Power Amplification System Using Doherty Amplifier With Linearization Circuit And Related Techniques
US Patent:
2013024, Sep 19, 2013
Filed:
Mar 7, 2013
Appl. No.:
13/788824
Inventors:
Cheryl V. Liss - Merrimack NH, US
John Muir - North Chelmsford MA, US
John Muir - North Chelmsford MA, US
Assignee:
AURIGA MEASUREMENT SYSTEMS, LLC - Chelmsford MA
International Classification:
H03F 3/68
US Classification:
330295
Abstract:
A power amplification system includes a linearizer circuit feeding a power amplifier to linearize the operation of the power amplifier. The linearizer circuit may shape the input signal of the power amplifier in a manner that complements the output power versus input power characteristic of the power amplifier. In some embodiments, the linearizer may increase the relative magnitude of higher power portions of the input signal while decreasing the relative magnitude of lower power portions of the input signal to provide an overall increase in the linearity of the power amplification system. The power amplifier may include a Doherty amplifier in some implementations.
Methods And Apparatuses For Use In Tuning Reactance In A Circuit Device
US Patent:
2013022, Aug 29, 2013
Filed:
Aug 27, 2012
Appl. No.:
13/595893
Inventors:
Ronald Eugene Reedy - San Diego CA, US
Dan William Nobbe - Crystal Lake IL, US
Tero Tapio Ranta - San Diego CA, US
Cheryl V. Liss - Merrimack NH, US
David Kovac - Arlington Heights IL, US
Dan William Nobbe - Crystal Lake IL, US
Tero Tapio Ranta - San Diego CA, US
Cheryl V. Liss - Merrimack NH, US
David Kovac - Arlington Heights IL, US
International Classification:
H03H 11/28
US Classification:
333 32, 307 98
Abstract:
Methods and apparatuses for use in tuning reactance are described. Open loop and closed loop control for tuning of reactances are also described. Tunable inductors and/or tunable capacitors may be used in filters, resonant circuits, matching networks, and phase shifters. Ability to control inductance and/or capacitance in a circuit leads to flexibility in operation of the circuit, since the circuit may be tuned to operate under a range of different operating frequencies.