Patents Assigned to Sarantel Limited
  • Patent number: 8736513
    Abstract: A backfire dielectrically loaded antenna for operation at a frequency in excess of 200 MHz includes a dielectric core having a relative dielectric constant greater than 5 and having an outer surface defining an interior volume the major part of which is occupied by solid material of the core; a three-dimensional antenna element structure including at least one pair of elongate conductive antenna elements disposed on or adjacent the side surface portion of the core and extending from a distal core surface portion towards a proximal core surface portion; a feed structure having an axially extending elongate laminate board including a transmission line section acting as a feed line which extends through a passage in the core from the distal core surface portion to the proximal core surface portion, and an antenna connection section having an integrally formed proximal extension of the transmission line section the width of which, in the plane of the laminate board, is greater than the width of the passage; and a
    Type: Grant
    Filed: January 27, 2011
    Date of Patent: May 27, 2014
    Assignee: Sarantel Limited
    Inventors: Andrew Robert Christie, David Michael Wither, Sinikka Lyyra
  • Patent number: 8692734
    Abstract: A dielectrically loaded quadrifilar helical antenna has four quarter turn helical elements centered on a common axis. Each helical element is metallized on the outer cylindrical surface of a solid dielectric core and each has a feed end and a linked end, the linked ends being connected together by a linking conductor encircling the core. At an operating frequency of the antenna the helical elements and the linking conductor together form two conductive loops each having an electrical length in the region of (2n?1)/2 times the wavelength, where n is an integer. Such an antenna tends to present a source impedance of at least 500 ohms to receiver circuitry to which it is connected. The invention includes an antenna assembly including a dielectrically antenna and a receiver having a radio frequency front-end stage with a differential input coupled to the feed ends of the helical elements.
    Type: Grant
    Filed: September 9, 2009
    Date of Patent: April 8, 2014
    Assignee: Sarantel Limited
    Inventor: Oliver Paul Leisten
  • Patent number: 8624795
    Abstract: A dual-band dielectrically loaded multifilar antenna has a first group of helical conductive antenna elements extending from feed connection nodes to an annular linking conductor 20U, and a second group of conductive helical antenna elements extending from the feed coupling nodes in the direction of the linking conductor to substantially open-circuit ends spaced from the linking conductor. The helical elements of the first group are half-turn elements having an electrical length of approximately one half wavelength at a first operating frequency of the antenna. The helical elements of the second group are approximately quarter-turn helical elements having an electrical length in the region of one quarter wavelength and a second operating frequency of the antenna. Each group of elements is associated with a respective mode of resonance for circularly polarized radiation.
    Type: Grant
    Filed: March 10, 2010
    Date of Patent: January 7, 2014
    Assignee: Sarantel Limited
    Inventor: Oliver Paul Leisten
  • Patent number: 8599101
    Abstract: A radio communication apparatus including: (a) a backfire dielectrically loaded antenna for operation at a frequency in excess of 200 MHz comprising: an electrically insulative dielectric core of a solid material having a relative dielectric constant greater than 5 and having an outer surface including oppositely directed distal and proximal surface portions extending transversely of an axis of the antenna and a side surface portion extending between the transversely extending surface portions, the core outer surface defining an interior volume the major part of which is occupied by the solid material of the core; a three-dimensional antenna element structure including at least one pair of elongate conductive antenna elements disposed on or adjacent the side surface portion of the core and extending from the distal core surface portion towards the proximal core surface portion; a feed structure in the form of an axially extending elongate laminate board comprising at least a transmission line section acting a
    Type: Grant
    Filed: January 27, 2011
    Date of Patent: December 3, 2013
    Assignee: Sarantel Limited
    Inventors: Andrew Robert Christie, David Michael Wither, Martyn Leslie Tongue, Frank Kwasi Frimpong
  • Patent number: 8558754
    Abstract: A dielectrically-loaded antenna has a cylindrical ceramic core, a three dimensional antenna element structure comprising co-extensive helical conductors plated on a cylindrical side surface of the core and a dielectrically-loaded antenna has a solid cylindrical core made of a ceramic material, helical antenna elements made of a ceramic material, co-extensive helical antenna elements plated on the core, connecting conductors on a distal end surface, a matching section in the form of a printed circuit board overlying the core distal end surface and a coaxial feeder housed in an axial bore passing through the core. For ease of manufacture, the laminate board of the matching section contains a ball grid array having a plurality of solder elements which serve to connect the matching network to both the surface connection elements on the distal core end surface and to the feeder.
    Type: Grant
    Filed: August 21, 2009
    Date of Patent: October 15, 2013
    Assignee: Sarantel Limited
    Inventors: Jenny Sarah Drake, Oliver Paul Leisten
  • Patent number: 8497815
    Abstract: A dielectrically loaded quadrifilar helical antenna has four quarter turn helical elements centered on a common axis. Each helical element is metallised on the outer cylindrical surface of a solid dielectric core and each has a feed end and a linked end, the linked ends being connected together by a linking conductor encircling the core. At an operating frequency of the antenna the helical elements and the linking conductor together form two conductive loops each having an electrical length in the region of (2n?1)/2 times the wavelength, where n is an integer. Such an antenna tends to present a source impedance of at least 500 ohms to receiver circuitry to which it is connected. The invention includes an antenna assembly including a dielectrically antenna and a receiver having a radio frequency front-end stage with a differential input coupled to the feed ends of the helical elements.
    Type: Grant
    Filed: November 28, 2007
    Date of Patent: July 30, 2013
    Assignee: Sarantel Limited
    Inventor: Oliver Paul Leisten
  • Publication number: 20130181881
    Abstract: Among the embodiments disclosed herein is an antenna assembly comprising the combination of a dielectrically loaded antenna and a housing, the housing incorporating a connector for coupling the antenna to host equipment. The antenna comprises an insulative core which has an outer surface and is shaped to define a central axis, and a laminate board on the central axis, the laminate board extending proximally from a proximal core surface portion oriented transversely with respect to the axis. The housing comprises a housing body which forms a hollow conductive shield for the laminate board, and is centred on the antenna axis, and the housing is shaped to provide a mounting surface which, in a cross-sectional plane perpendicular to the axis, defines a periphery of an area in the said plane which area is at least as great as the cross-sectional area of the said proximal portion of the antenna.
    Type: Application
    Filed: January 3, 2013
    Publication date: July 18, 2013
    Applicant: SARANTEL LIMITED
    Inventor: Sarantel Limited
  • Patent number: 8456375
    Abstract: In a dielectrically-loaded multifilar helical antenna, a conductive phasing ring is arranged between and couples together feed nodes and the helical radiating elements. The phasing ring includes an annular conductive path having an electrical length equivalent to a full wavelength at the operating frequency so as to be resonant at that frequency. The helical elements are coupled to the outer periphery of the phasing ring at respective spaced apart coupling locations. The helical elements may include open-circuit or closed-circuit elongate conductive tracks, or a combination of both. In the case of the helical elements being closed-circuit tracks, these tracks are interconnected by a second resonant ring, which is resonant at the same frequency as or a different frequency from the first resonant ring. The invention is applicable to both end-fire and back-fire helical antennas.
    Type: Grant
    Filed: July 2, 2010
    Date of Patent: June 4, 2013
    Assignee: Sarantel Limited
    Inventor: Oliver Paul Leisten
  • Publication number: 20130135169
    Abstract: This application relates to antennas including, for example, an antenna for operation at a frequency in excess of 200 MHz comprising: an insulative substrate having a central axis, an axial passage extending therethrough and an outer substrate surface which extends around the axis; a three-dimensional antenna element structure including at least one pair of axially coextensive elongate conductive antenna elements on or adjacent the outer substrate surface; and an axial feeder structure which extends through the passage and comprises an elongate laminate board wherein the laminate board proximal end portion includes lateral extensions projecting in opposite lateral directions, and wherein, adjacent the laminate board proximal end portion, the substrate has recesses on opposite sides of the axis which receive at least edge parts of the said lateral extensions of the laminate board proximal end portion.
    Type: Application
    Filed: November 20, 2012
    Publication date: May 30, 2013
    Applicant: SARANTEL LIMITED
    Inventor: Sarantel Limited
  • Patent number: 8436783
    Abstract: A dual-band dielectrically loaded helical antenna for circularly polarised signals has two groups of helical antenna elements. In each group there are at least four such elements and they are connected at their distal ends to a respective feed coupling node and at their proximal ends to a common linking conductor. Each group includes pairs of neighbouring such antenna elements, each pair having one electrically short element and one electrically long element, and the arrangement of the elements is such that in each group the number of pairs in which, in a given direction around the core, the short element precedes the long element is equal to the number of pairs in which, in the same direction, the long element precedes the short element.
    Type: Grant
    Filed: March 10, 2010
    Date of Patent: May 7, 2013
    Assignee: Sarantel Limited
    Inventor: Oliver Paul L Eisten
  • Publication number: 20130099999
    Abstract: This disclosure relates to a radiofrequency circuit assembly and a dielectrically-loaded antenna for use in the assembly. The antenna comprises a solid electrically insulative core having a passage therethrough extending from a first core surface portion to a second, oppositely facing core surface portion, and a printed circuit feeder structure secured in the core passage and having exposed antenna mounting projections at opposite respective ends of the passage. The printed circuit board mounting the antenna has a cut-out dimensioned to accommodate the antenna core with the passage extending substantially parallel to the plane of the board. The antenna mounting projections at both ends of the passage engage respective edge portions of the said printed circuit board adjacent the cut-out so that the antenna core is supported by the printed circuit board between spaced-apart mounting locations adjacent the oppositely facing core surface portions.
    Type: Application
    Filed: October 17, 2012
    Publication date: April 25, 2013
    Applicant: SARANTEL LIMITED
    Inventor: Sarantel Limited
  • Publication number: 20120299798
    Abstract: A dielectrically loaded antenna for operation at first and second frequencies above 200 MHz with circularly polarized radiation includes an electrically insulative dielectric core of solid material having a relative dielectric constant greater than 5, and a three-dimensional antenna element structure linked to a pair of feed coupling nodes. The antenna element structure is divided into a distal section and a proximal section respectively having a first set of elongate conductors on or adjacent a distal part of the core side surface portion and a second set of elongate conductors on or adjacent a proximal part of the core side surface portion, and wherein the first set of conductors is resonant at the first operating frequency and the second set of conductors is resonant at the second operating frequency.
    Type: Application
    Filed: May 22, 2012
    Publication date: November 29, 2012
    Applicant: SARANTEL LIMITED
    Inventor: Oliver Paul Leisten
  • Publication number: 20120287016
    Abstract: A method of manufacturing a dielectrically loaded antenna having an operating frequency in excess of 200 MHz, the antenna having an electrically insulative core, the method including steps of: forming a first patterned layer of conductive material having a plurality of inner conductive tracks on at least one surface of the core of the antenna; depositing a layer of insulative material over at least a portion of the first layer of conductive material; and forming a second patterned layer of conductive material having a plurality of outer conductive tracks, at least partially overlapping the inner conductive tracks.
    Type: Application
    Filed: May 9, 2012
    Publication date: November 15, 2012
    Applicant: SARANTEL LIMITED
    Inventors: Beata Zalinska, Oliver Paul Leisten
  • Patent number: 8279134
    Abstract: A dielectrically loaded backfire helical antenna has a cylindrical ceramic core and a feed structure which passes axially through the core to a distal end face of the core where it is connected to helical conductors located on the outside of the core. Opening out on the proximal end face of the core is a cavity which is coaxial with the feed structure. A conductive balun layer encircling a portion of the core extends over the proximal end face of the core and the wall of the cavity to connect the helical elements to the feeder structure when it emerges into the cavity. The presence of the cavity and accommodating some of the length of the balun in the cavity allows a reduction in the size and weight of a dielectrically loaded backfire antenna.
    Type: Grant
    Filed: February 17, 2005
    Date of Patent: October 2, 2012
    Assignee: Sarantel Limited
    Inventors: David Michael Wither, Oliver Paul Leisten
  • Patent number: 8279135
    Abstract: A dielectrically loaded backfire helical antenna has a cylindrical ceramic core and a feed structure which passes axially through the core to a distal end face of the core where it is connected to helical conductors located on the outside of the core. Opening out on the proximal end face of the core is a cavity which is coaxial with the feed structure. A conductive balun layer encircling a portion of the core extends over the proximal end face of the core and the wall of the cavity to connect the helical elements to the feeder structure when it emerges into the cavity. The presence of the cavity and accommodating some of the length of the balun in the cavity allows a reduction in the size and weight of a dielectrically loaded backfire antenna.
    Type: Grant
    Filed: September 9, 2009
    Date of Patent: October 2, 2012
    Assignee: Sarantel Limited
    Inventors: David Michael Wither, Oliver Paul Leisten
  • Patent number: 8212738
    Abstract: A dielectrically-loaded helical antenna has a cylindrical ceramic core bearing metallised helical antenna elements which are coupled to a coaxial feeder structure passing axially through the core. Secured to the end face of the core is an impedance matching section in the form of a laminate board. The matching section embodies a shunt capacitance and a series inductance.
    Type: Grant
    Filed: March 15, 2010
    Date of Patent: July 3, 2012
    Assignee: Sarantel Limited
    Inventors: Oliver Paul Leisten, Andrew Robert Christie, Thomas Alan Clupper, John J Squires
  • Patent number: 8207905
    Abstract: A dielectrically-loaded helical antenna has a cylindrical ceramic core bearing metallised helical antenna elements which are coupled to a coaxial feeder structure passing axially through the core. Secured to the end face of the core is an impedance matching section in the form of a laminate board. The matching section embodies a shunt capacitance and a series inductance.
    Type: Grant
    Filed: October 7, 2011
    Date of Patent: June 26, 2012
    Assignee: Sarantel Limited
    Inventors: Oliver Paul Leisten, Andrew Robert Christie, Thomas Alan Clupper, John J Squires
  • Patent number: 8134506
    Abstract: An antenna arrangement which includes two antennas which are resonant at a common operating frequency. The arrangement includes a circuit which combines output signals from each of the antennas to provide a combined signal output. Each antenna has an electrically insulative core of solid material having a relative dielectric constant greater than 5 and a three-dimensional antenna element structure. The structure includes at least a pair of elongate conductive antenna elements disposed on or adjacent a surface of the core.
    Type: Grant
    Filed: December 14, 2007
    Date of Patent: March 13, 2012
    Assignee: Sarantel Limited
    Inventor: Oliver Paul Leisten
  • Publication number: 20120026066
    Abstract: An antenna for circularly polarised radiation at an operating frequency in excess of 200 MHz has a substrate in the form of a disc-shaped dielectric tile with parallel planar surfaces. The upper surface bears a conductive pattern including a resonant ring and a number of open-circuit radiating elements each having an electrical length of a quarterwave at the resonant frequency of the ring. The radiating elements extend outwardly from the ring and are joined to the ring at uniformly spaced locations. Each radiating element extends in a direction which has both a radial component and a tangential component and follows a generally spiral path. A pair of central feed nodes are coupled to the inside of the ring by a pair of feed tracks lying on a diameter. Dual-frequency and dual-polarisation variants are also disclosed.
    Type: Application
    Filed: July 29, 2011
    Publication date: February 2, 2012
    Applicant: SARANTEL LIMITED
    Inventor: Oliver Paul Leisten
  • Patent number: 8089421
    Abstract: A dielectrically loaded multifilar antenna has an electrically insulative solid core bearing an antenna element structure having four pairs of substantially helical radiating elements spaced apart around a central axis of the antenna. Each pair of oppositely located antenna elements forms part of a conductive loop having an effective electrical length in the region of N guide wavelengths at the operating frequency, where N is an integer and is at least 2. Typically, each helical element executes substantially a full turn around the axis on the outer surface of the core. The antenna offers an improved gain-bandwidth product compared with typical prior dielectrically loaded multifilar helical antennas, and a 3 dB beamwidth of at least 90° for circularly polarized radiation.
    Type: Grant
    Filed: May 13, 2009
    Date of Patent: January 3, 2012
    Assignee: Sarantel Limited
    Inventors: Oliver Paul Leisten, Nicholas Roger Padfield