Ramanamurthy V Darapu

US Patent:

20040021535, Feb 5, 2004

Filed:

Jul 31, 2002

Appl. No.:

10/209709

Inventors:

Kenneth Buer - Gilbert AZ, US
Ramanamurthy Darapu - Chandler AZ, US
John Decamp - Mesa AZ, US
Deborah Dendy - Tempe AZ, US
Phillip Denisuk - Chandler AZ, US
Noel Lopez - Phoenix AZ, US
Edwin Stanfield - Queen Creek AZ, US

International Classification:

H01P007/10

US Classification:

333/219100

Abstract:

A method for affixing a resonator to a printed circuit board is provided. The method uses a thin metal film which may be affixed to a surface of a stand off, or directly to a surface of a resonator. The metalized surface may be affixed to a printed circuit board using a molten agent with a surface tension which withstands the downward force exerted by the puck's weight. The metalized surface may be affixed to a printed circuit board using a solder paste and the solder is allowed to reflow. The surface tension of the molten solder causes the resonator (or resonator puck) to self-center, ensuring proper placement and eliminating the need for repositioning. Since the resonator is not positioned using traditional glues which are subject to shifting during transportation or curing, then the resonator is not subject to shifting, eliminating the need to reposition the resonator after the resonator becomes fixed.

US Patent:

20090149150, Jun 11, 2009

Filed:

Dec 5, 2007

Appl. No.:

11/950831

Inventors:

Kenneth V. Buer - Gilbert AZ, US
Gaurav Menon - Gilbert AZ, US
Ramanamurthy V. Darapu - Gilbert AZ, US
Dean Muellenberg - Tempe AZ, US

Assignee:

VIASAT, INC. - Carlsbad CA

International Classification:

H04B 1/26

US Classification:

455326

Abstract:

Systems, devices and methods are disclosed for suppressing the 2LO frequency spur, output from a mixer. In various exemplary embodiments, a DC bias circuit is electrically connected to provide DC bias to one or more non-linear elements of the mixer. The biasing voltage is used to cause the current-voltage characteristics and/or junction capacitances between non-linear elements to be more symmetric and/or to suppress 2LO leakage currents that form 2LO frequency spurs at the output of the mixer. The non-linear elements may comprise one of: BJT's, diodes, and FET's. The mixer may be one of: a subharmonic mixer; a fundamental resistive mixer; a fundamental subharmonic transconductance mixer; and a fundamental transconductance mixer comprising an anti-parallel diode pair. The system may further be configured to automatically determine an appropriate DC bias voltage level that will improve one of the LO-IF isolation and the LO-RF isolation.

US Patent:

20200366259, Nov 19, 2020

Filed:

Jan 17, 2019

Appl. No.:

16/959973

Inventors:

- CARLSBAD CA, US
Kenneth V. BUER - Gilbert AZ, US
Michael R. LYONS - Gilbert AZ, US
Gary P. ENGLISH - Chanlder AZ, US
Qiang R. CHEN - Phoenix AZ, US
Ramanamurthy V. DARAPU - Gilbert AZ, US
Douglas J. MATHEWS - Mesa AZ, US
Mark S. BERKHEIMER - Tempe AZ, US
Brandon C. DRAKE - Mesa AZ, US

Assignee:

VIASAT, INC. - CARLSBAD CA

International Classification:

H03F 3/213
H01L 23/495
H01L 23/498
H01L 23/66
H01L 23/00
H01L 21/48
H05K 1/18
H03F 1/56

Abstract:

A packaged semiconductor chip includes a power amplifier die including a semiconductor substrate, and an input contact pad, an output contact pad, first and second direct-current (DC) contact pads, one or more transistors having an input coupled to the input contact pad, and an input bias coupling path electrically coupling the first DC contact pad to the second DC contact pad and the input contact pad implemented on the semiconductor substrate. The chip further includes a lead frame having one or more radio-frequency input pins electrically coupled to the input contact pad, one or more radio-frequency output pins electrically coupled to the output contact pad, and first and second input bias pins electrically coupled to the first and second DC contact pads, respectively.

US Patent:

20200358467, Nov 12, 2020

Filed:

Feb 1, 2019

Appl. No.:

16/960823

Inventors:

- Carlsbad CA, US
Ramanamurthy V. DARAPU - Gilbert AZ, US
Martin GIMERSKY - Lausanne, CH
David E. PETTIT - Gilbert AZ, US
Bill T. AGAR - SCOTTSDALE AZ, US

Assignee:

VIASAT, INC. - Carlsbad CA

International Classification:

H04B 1/04
H04B 1/44
H04B 17/15
H04B 17/11
H04B 17/21
H04B 17/29
H04B 1/12

Abstract:

Methods and devices for radio frequency (RF) loopback for transceivers are described. A transceiver for communicating RF signals with a target device may transmit signals at a transmit frequency and receive signals at a (different) receive frequency. The transceiver may include a waveguide diplexer for separating and combining signals based on frequency. The transceiver may be configured to couple a loopback signal from a common port of the waveguide diplexer; the loopback signal may be based on a transmit signal. The transceiver may include a loopback translator to translate the loopback signal from the transmit frequency to the receive frequency and provide the translated loopback signal to a receiver used for receiving signals from the target device. The receiver may compare the translated loopback signal with a representation of the transmit signal to generate a compensation signal. A transmitter may use the compensation signal to adjust subsequent transmit signals.

US Patent:

20200267575, Aug 20, 2020

Filed:

Jan 21, 2020

Appl. No.:

16/748597

Inventors:

- Carlsbad CA, US
Clifford K. Burdick - Vista CA, US
Ian Cleary - Tempe AZ, US
Ramanamurthy V. Darapu - Gilbert AZ, US
David H. Irvine - Carlsbad CA, US
Philip A. Lampe - Encinitas CA, US

International Classification:

H04W 24/02
H04B 7/185

Abstract:

The described features generally relate to determining dynamic signal quality criteria for an installation of satellite terminals for communications in a satellite communications system. In particular, the signal quality criteria for an installation may be based on an identified position of the satellite terminal to be installed, and in some examples based on the positions and signal characteristics of neighboring satellite terminals that have already been installed. In some examples, a signal quality map may be generated for a service beam coverage area, based on predetermined transmission characteristics and/or measured transmissions from a number of satellite terminals served by a communications satellite. The generated signal quality map may then be used to determine a signal quality threshold for the installation of a satellite terminal being installed for communications in a satellite communications system.

US Patent:

20180324606, Nov 8, 2018

Filed:

Jul 10, 2018

Appl. No.:

16/031926

Inventors:

- Carlsbad CA, US
Clifford K. Burdick - Vista CA, US
Ian A. Cleary - Tempe AZ, US
Ramanamurthy V. Darapu - Gilbert AZ, US
David H. Irvine - Carlsbad CA, US
Philip A. Lampe - Encinitas CA, US

International Classification:

H04W 24/02
H04B 7/185

Abstract:

The described features generally relate to determining dynamic signal quality criteria for an installation of satellite terminals for communications in a satellite communications system. In particular, the signal quality criteria for an installation may be based on an identified position of the satellite terminal to be installed, and in some examples based on the positions and signal characteristics of neighboring satellite terminals that have already been installed. In some examples, a signal quality map may be generated for a service beam coverage area, based on predetermined transmission characteristics and/or measured transmissions from a number of satellite terminals served by a communications satellite. The generated signal quality map may then be used to determine a signal quality threshold for the installation of a satellite terminal being installed for communications in a satellite communications system.

US Patent:

20170251381, Aug 31, 2017

Filed:

Feb 26, 2016

Appl. No.:

15/055180

Inventors:

- Carlsbad CA, US
Clifford K. Burdick - Vista CA, US
Ian A. Cleary - Tempe AZ, US
Ramanamurthy V. Darapu - Gilbert AZ, US
David H. Irvine - Carlsbad CA, US
Philip A. Lampe - Encinitas CA, US

International Classification:

H04W 24/02
H04W 16/22
H04W 64/00
H04W 84/06
H04W 52/24
H04W 52/26

Abstract:

The described features generally relate to determining dynamic signal quality criteria for an installation of satellite terminals for communications in a satellite communications system. In particular, the signal quality criteria for an installation may be based on an identified position of the satellite terminal to be installed, and in some examples based on the positions and signal characteristics of neighboring satellite terminals that have already been installed. In some examples, a signal quality map may be generated for a service beam coverage area, based on predetermined transmission characteristics and/or measured transmissions from a number of satellite terminals served by a communications satellite. The generated signal quality map may then be used to determine a signal quality threshold for the installation of a satellite terminal being installed for communications in a satellite communications system.