Patents by Inventor John Kvarnstrand
John Kvarnstrand has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
-
Patent number: 11506697Abstract: A measurement device for measuring performance of at least one antenna system in a first frequency band and in a second frequency band. The measurement device including an outer chamber having inwardly radio frequency reflective walls configured to enclose the antenna system, an inner chamber deployable inside the outer chamber, the inner chamber having radio frequency absorptive walls configured to enclose the antenna system, a first test antenna arrangement arranged inside the outer chamber and configured for a measurement operation in the first frequency band, and a second test antenna arrangement arranged inside the inner chamber and configured for a measurement operation in the second frequency band, thereby enabling measuring performance of the antenna system in a reflective radio frequency environment by the first test antenna arrangement and measuring performance in an essentially anechoic radio frequency environment by the second test antenna arrangement.Type: GrantFiled: June 17, 2019Date of Patent: November 22, 2022Assignee: BLUETEST ABInventors: Robert Rehammar, John Kvarnstrand, Klas Arvidsson
-
Publication number: 20210318369Abstract: A measurement device for measuring performance of at least one antenna system in a first frequency band and in a second frequency band. The measurement device including an outer chamber having inwardly radio frequency reflective walls configured to enclose the antenna system, an inner chamber deployable inside the outer chamber, the inner chamber having radio frequency absorptive walls configured to enclose the antenna system, a first test antenna arrangement arranged inside the outer chamber and configured for a measurement operation in the first frequency band, and a second test antenna arrangement arranged inside the inner chamber and configured for a measurement operation in the second frequency band, thereby enabling measuring performance of the antenna system in a reflective radio frequency environment by the first test antenna arrangement and measuring performance in an essentially anechoic radio frequency environment by the second test antenna arrangement.Type: ApplicationFiled: June 17, 2019Publication date: October 14, 2021Inventors: Robert REHAMMAR, John KVARNSTRAND, Klas ARVIDSSON
-
Patent number: 11047894Abstract: A method and apparatus for production testing of a device under test (DUT) in a chamber is disclosed, the chamber defining an internal cavity therein, adapted to enclose the DUT, and including walls having inwardly facing surfaces of an electromagnetically reflective material, thereby supporting several resonant modes within the internal cavity.Type: GrantFiled: January 15, 2019Date of Patent: June 29, 2021Assignee: Bluetest ABInventors: John Kvarnstrand, Magnus Franzén, Eric Lundin
-
Publication number: 20200341044Abstract: A method and apparatus for production testing of a device under test (DUT) in a chamber is disclosed, the chamber defining an internal cavity therein, adapted to enclose the DUT, and including walls having inwardly facing surfaces of an electromagnetically reflective material, thereby supporting several resonant modes within the internal cavity.Type: ApplicationFiled: January 15, 2019Publication date: October 29, 2020Inventors: John KVARNSTRAND, Magnus FRANZÉN, Eric LUNDIN
-
Patent number: 10725079Abstract: A new measurement arrangement and method for measuring the performance of a device under test, such as an antenna, a mobile phone and other wireless terminals, are disclosed. The chamber defines an internal cavity therein, adapted to enclose the device under test, and including walls of an inwardly reflective material, rendering the walls reflective to electromagnetic waves, thereby simulating a multi-path environment. Thus, the chamber is a reverberation chamber. Further, at least one first chamber antenna and at least one second chamber antenna, are arranged in the cavity, the first and second chamber antennas being configured to transmit and receive electromagnetic waves within a first predefined frequency range and within a second predefined frequency range, respectively. A measuring instrument is connected to the device under test and the chamber antennas, for measuring the transmission between them.Type: GrantFiled: March 5, 2018Date of Patent: July 28, 2020Assignee: Bluetest ABInventor: John Kvarnstrand
-
Publication number: 20190391195Abstract: A new measurement arrangement and method for measuring the performance of a device under test, such as an antenna, a mobile phone and other wireless terminals, are disclosed. The chamber defines an internal cavity therein, adapted to enclose the device under test, and including walls of an inwardly reflective material, rendering the walls reflective to electromagnetic waves, thereby simulating a multi-path environment. Thus, the chamber is a reverberation chamber. Further, at least one first chamber antenna and at least one second chamber antenna, are arranged in the cavity, the first and second chamber antennas being configured to transmit and receive electromagnetic waves within a first predefined frequency range and within a second predefined frequency range, respectively. A measuring instrument is connected to the device under test and the chamber antennas, for measuring the transmission between them.Type: ApplicationFiled: March 5, 2018Publication date: December 26, 2019Applicant: Bluetest ABInventor: John KVARNSTRAND
-
Patent number: 7187288Abstract: An embodiment of the present invention provides an RFID tag reading system, comprising an antenna system associated with a portal through which said RFID tag may pass, said antenna system comprising: a plurality of non-uniformly spaced antenna elements arranged substantially linearly; a power divider for dividing transmit power thereby coupling signals to said plurality of antenna elements; and a beamforming network capable of phase shifting the signals between the power divider and the plurality of antenna elements such that radiated signals from each antenna element add coherently such that the radiated electromagnetic energy is focused at a focal point in the near field region or in the Fresnel region of said antenna system.Type: GrantFiled: October 6, 2004Date of Patent: March 6, 2007Assignee: Paratek Microwave, Inc.Inventors: Greg Mendolia, John Kvarnstrand, Bing Foo, Cornelius du Toit, Nicolaas du Toit
-
Patent number: 7183922Abstract: An apparatus capable of tracking a target, comprising at least one near-field focused antenna comprising an array of elements and a phase shifter to form multiple fixed beams in the near-field, a sensor capable of sensing the location of the target, and a controller capable of accepting position information and capable of activating the proper fixed beam along a course so as to enable the near-field focused beams to track the target. The array of elements may be substantially linear and the sensor may be optical, mechanical, thermal, or sonic position detection subsystems.Type: GrantFiled: October 6, 2004Date of Patent: February 27, 2007Assignee: Paratek Microwave, Inc.Inventors: Greg Mendolia, John Kvarnstrand, Bing Foo, Cornelis du Toit, Nicolaas du Toit
-
Patent number: 7034636Abstract: An apparatus for reducing influence by selected signal components in a communication link includes a first signal line conveying a first communication signal including a desired signal component and at least one undesired signal component; a second signal line conveying a second communication signal substantially including at least the at least one undesired signal component; a signal treating unit coupled with the second signal line for affecting at least one parameter associated with the second communication signal to present a modified second communication signal at a first output locus coupled for combining the modified second communication signal with the first communication signal to present an improved communication signal at a second output locus. The at least one undesired signal component affects the improved communication signal less than the at least one undesired signal component affects the first communication signal.Type: GrantFiled: August 5, 2004Date of Patent: April 25, 2006Assignee: Paratek Microwave IncorporatedInventors: Khosro Shamsaifar, Yongfei Zhu, John Kvarnstrand, Louise Sengupta
-
Publication number: 20050200422Abstract: An embodiment of the present invention further provides an apparatus capable of reducing selected signal components in a communication link comprising a signal line conveying a communication signal including a desired signal component and at least one undesired signal component; a first signal loop coupled to the first signal line capable of generating a signal such that when combined with the first signal line reduces a first of the at least one undesired signal components; and a second signal loop coupled to the first signal line capable of generating a signal such that when combined with the first signal line reduces a second of the at least one undesired signal components. The first signal loop may include a tunable delay enabling the generation of the signal that when combined with the first signal line reduces a first of the at least one undesired signal components.Type: ApplicationFiled: February 25, 2005Publication date: September 15, 2005Inventors: Khosro Shamsaifar, Yongfei Zhu, John Kvarnstrand, Louise Sengupta
-
Publication number: 20050159187Abstract: An embodiment of the present invention provides an antenna system, comprising a plurality of non-uniformly spaced antenna elements arranged substantially linearly, a power divider for dividing transmit power thereby coupling signals to the plurality of antenna elements, a phase shifter capable of phase shifting the signals between the power divider and the plurality of antenna elements such that radiated signals from each antenna element add coherently such that the radiated electromagnetic energy may be focused at a focal point in the near field region or in the Fresnel region of the antenna system. An embodiment of the present invention may also provide at least one additional receive antenna element capable of receiving signals backscattered from at least one RFID tag located in the near field of the focused array and the divider may create substantially equal power levels feeding each antenna element.Type: ApplicationFiled: October 6, 2004Publication date: July 21, 2005Inventors: Greg Mendolia, John Kvarnstrand, Bing Foo, Cornelis Toit, Nicolaas Toit
-
Publication number: 20050110641Abstract: An embodiment of the present invention provides an RFID tag reading system, comprising an antenna system associated with a portal through which said RFID tag may pass, said antenna system comprising: a plurality of non-uniformly spaced antenna elements arranged substantially linearly; a power divider for dividing transmit power thereby coupling signals to said plurality of antenna elements; and a beamforming network capable of phase shifting the signals between the power divider and the plurality of antenna elements such that radiated signals from each antenna element add coherently such that the radiated electromagnetic energy is focused at a focal point in the near field region or in the Fresnel region of said antenna system.Type: ApplicationFiled: October 6, 2004Publication date: May 26, 2005Inventors: Greg Mendolia, John Kvarnstrand, Bing Foo, Cornelis du Toit, Nicolaas du Toit
-
Publication number: 20050110674Abstract: An apparatus capable of tracking a target, comprising at least one near-field focused antenna comprising an array of elements and a phase shifter to form multiple fixed beams in the near-field, a sensor capable of sensing the location of the target, and a controller capable of accepting position information and capable of activating the proper fixed beam along a course so as to enable the near-field focused beams to track the target. The array of elements may be substantially linear and the sensor may be optical, mechanical, thermal, or sonic position detection subsystems. In an embodiment of the present invention the target may be at least one RFID tag and the phase shifter may include a voltage tunable dielectric. The controller may control a plurality of switches which activate at least one beam forming network. Further, the tracking may occur along a predetermined course, and the predetermined course may be along a conveyor line or through a doorway.Type: ApplicationFiled: October 6, 2004Publication date: May 26, 2005Inventors: Greg Mendolia, John Kvarnstrand, Bing Foo, Cornelis Toit, Nicolaas Toit
-
Publication number: 20050007212Abstract: An apparatus for reducing influence by selected signal components in a communication link includes a first signal line conveying a first communication signal including a desired signal component and at least one undesired signal component; a second signal line conveying a second communication signal substantially including at least the at least one undesired signal component; a signal treating unit coupled with the second signal line for affecting at least one parameter associated with the second communication signal to present a modified second communication signal at a first output locus coupled for combining the modified second communication signal with the first communication signal to present an improved communication signal at a second output locus. The at least one undesired signal component affects the improved communication signal less than the at least one undesired signal component affects the first communication signal.Type: ApplicationFiled: August 5, 2004Publication date: January 13, 2005Inventors: Khosro Shamsaifar, Yongfei Zhu, John Kvarnstrand, Louise Sengupta
-
Patent number: 6801102Abstract: A tunable electrical filter constructed pursuant to the teachings of the present invention includes: (a) a plurality of resonator units coupled between an input locus and an output locus; and (b) a plurality of tunable dielectric varactor units; respective individual varactor units of the plurality of varactor units being coupled between respective pairs of the plurality of resonator units, coupled between the plurality of resonator units and the input locus, and coupled between the plurality of resonator units and the output locus.Type: GrantFiled: September 20, 2002Date of Patent: October 5, 2004Assignee: Paratek Microwave IncorporatedInventors: Khosro Shamsaifar, Yongfei Zhu, John Kvarnstrand, Louise Sengupta
-
Publication number: 20030176179Abstract: A wireless local area network that utilizes a dynamically reconfigurable wireless network antenna that comprises at least one multi-layered RF module, said at least one RF module further comprising at least one RF connector for receipt of at least one RF signal and at least one layer of tunable dielectric material and one layer of metal fabricated into said RF module; an RF motherboard for acceptance of RF signals and distribution of the transmit energy to said RF module at the appropriate phases to generate a beam in the commanded direction and width; and a controller for determining the correct voltage signal to send to said at least one multi-layered RF module.Type: ApplicationFiled: March 14, 2003Publication date: September 18, 2003Inventors: Ken Hersey, Shuguang Chen, Cornelis Du Toit, John Kvarnstrand, Jay Patel, Donya He, Peter Acsadi, Chenggang Sui
-
Publication number: 20030052750Abstract: A tunable electrical filter constructed pursuant to the teachings of the present invention includes: (a) a plurality of resonator units coupled between an input locus and an output locus; and (b) a plurality of tunable dielectric varactor units; respective individual varactor units of the plurality of varactor units being coupled between respective pairs of the plurality of resonator units, coupled between the plurality of resonator units and the input locus, and coupled between the plurality of resonator units and the output locus.Type: ApplicationFiled: September 20, 2002Publication date: March 20, 2003Inventors: Khosro Shamsaifar, Yongfei Zhu, John Kvarnstrand, Louise Sengupta