Multi-layered multi-band antenna with parasitic radiator

• US 8,654,023 B2
• Filed: 02/22/2012
• Issued: 02/18/2014
• Est. Priority Date: 09/02/2011
• Status: Active Grant

• Current Assignee: DockOn AG
• Original Assignee: DockOn AG
• Inventors: Brown, Forrest James, Orsi, Ryan James, Foster, Matthew Robert
• Primary Examiner(s): Nguyen, Hoang V
• Application Number:
  US13/402,817
• Publication Number:
  US 20130057441A1
• Time in Patent Office: 727 Days
• Field of Search: 343/741, 343/745, 343/748, 343/749, 343/866
• US Class Current: 343/748
• CPC Class Codes: H01Q 1/48 Earthing means; Earth screens; Counterpoises
• CPC Class Codes: H01Q 21/24 Combinations of antenna units polarised in different directions for transmitting or receiving circularly and elliptically polarised waves or waves linearly polarised in any direction circularly polarised patch antennas H01Q9/0428; circularly polarised horns H01Q13/0241; cross-polarised horns H01Q13/0258; polarisation converters H01Q15/242; cross-polarised rear feeds H01Q19/136; crossed polarisation dual antenna H01Q25/001
• CPC Class Codes: H01Q 21/30 Combinations of separate antenna units operating in different wavebands and connected to a common feeder system
• CPC Class Codes: H01Q 25/001 Crossed polarisation dual antennas orthomode horns H01Q13/0258; cross-polarised rear feeds H01Q19/136; orthomode transducers H01P1/161
• CPC Class Codes: H01Q 5/378 Combination of fed elements with parasitic elements
• CPC Class Codes: H01Q 7/005 with variable reactance for tuning the antenna
• CPC Class Codes: H01Q 9/0407 Substantially flat resonant element parallel to ground plane, e.g. patch antenna dipole H01Q9/285; monopole H01Q9/40
• CPC Class Codes: H01Q 9/285 Planar dipole H01Q9/065 takes precedence; patch antenna H01Q9/0407
• CPC Class Codes: H01Q 9/30 with feed to end of elongated active element, e.g. unipole H01Q9/44 takes precedence

Abstract

Embodiments provide multi-band, compound loop antennas (multi-band antennas). Embodiments of the multi-band antennas produce signals at two or more frequency bands, with the two or more frequency bands capable of being adjusted and tuned independently of each other. Embodiments of a multi-band antenna are comprised of at least one electric field radiator and at least one monopole formed out of the magnetic loop. At a particular frequency, the at least one electric field radiator in combination with various portions of the magnetic loop resonate and radiate an electric field at a first frequency band. At yet another particular frequency, the at least one monopole in combination with various portions of the magnetic loop resonate and radiate an electric field at a second frequency band. The shape of the magnetic loop can be tuned to increase the radiation efficiency at particular frequency bands and enable the multi-band operation of antenna embodiments.

Claims

1. A multi-layered planar multi-band antenna, comprising:

a magnetic loop located on a first plane and configured to generate a magnetic field, the magnetic loop forming two or more horizontal sections and two or more vertical sections formed at substantially 90 degree angles between the two or more horizontal sections and the two or more vertical sections, a first horizontal section among the two or more horizontal sections emitting a first electric field at a low frequency band, a second horizontal section among the two or more horizontal sections emitting a second electric field at a high frequency band, wherein the magnetic loop has a first inductive reactance adding to a total inductive reactance of the multi-band antenna; and

a parasitic electric field radiator located on a second plane below the first plane, at least half of the parasitic electric field radiator positioned on the second plane at a position that would place the electric field radiator within the magnetic loop if the position was on the first plane, the parasitic electric field radiator not coupled to the magnetic loop, the parasitic electric field radiator configured to emit a third electric field at the low frequency band that reinforces the first electric field and orthogonal to the magnetic field, wherein the parasitic electric field radiator has a first capacitive reactance adding to a total capacitive reactance of the multi-band antenna, wherein a physical arrangement between the electric field radiator and the magnetic loop results in a second capacitive reactance adding to the total capacitive reactance, and wherein the total inductive reactance substantially matches the total capacitive reactance.

2. The antenna as recited in claim 1, wherein the parasitic electric field radiator reflects an impedance into the magnetic loop and realigns the first electric field and the second electric field parallel to the third electric field.

3. The antenna as recited in claim 1, wherein positioning the parasitic electric field radiator near an edge of the magnetic loop along the second plane increases an electrical length of the parasitic electric field radiator.

4. The antenna as recited in claim 1, wherein positioning the parasitic electric field radiator near a center of the magnetic loop along the second plane decreases an electrical length of the electric field radiator.

5. The antenna as recited in claim 1, wherein one or more first corners of the two or more horizontal sections and one or more second corners of the one or more vertical sections are cut at an angle.

6. The antenna as recited in claim 1, wherein the two or more horizontal sections and the one or more vertical sections are arranged to make one or more high voltage nodes within the magnetic loop and one or more high current nodes within the magnetic loop additive at the high frequency band and the low frequency band.

7. The antenna as recited in claim 1, wherein one or more additive sections among the one or more vertical sections, and one or more canceling sections among the one or more vertical sections, tune an electrical length of the magnetic loop to substantially match one wavelength, wherein the one or more additive sections add capacitance to the magnetic loop and the one or more canceling sections decrease a length of the magnetic loop.

8. The antenna as recited in claim 1, further comprising a loading capacitor located on the second plane, the loading capacitor having a third capacitance reactance adding to the total capacitive reactance.

9. The antenna as recited in claim 1, wherein the loading capacitor is oriented orthogonal to the first electric field and the second electric field.

10. The antenna as recited in claim 1, wherein the low frequency band and the high frequency band are not harmonically related.