MIMO antenna arrays built on metamaterial substrates

• US 9,054,423 B2
• Filed: 08/08/2014
• Issued: 06/09/2015
• Est. Priority Date: 12/01/2008
• Status: Active Grant

• Current Assignee: Drexel University
• Original Assignee: Drexel University
• Inventors: Dandekar, Kapil R., Mookiah, Prathaban
• Primary Examiner(s): Frech, Karl D
• Application Number:
  US14/455,411
• Publication Number:
  US 20140347240A1
• Time in Patent Office: 305 Days
• Field of Search: 343/893, 343/787, 343/890, 343/3, 343/77
• US Class Current: 1/1
• CPC Class Codes: B65D 65/403 with at least one corrugated layer
• CPC Class Codes: H01Q 1/38 formed by a conductive layer on an insulating support patch antennas H01Q9/0407; microstrip dipole antennas H01Q9/065; microstrip slot antennas H01Q13/106; transmission line microstrip antennas H01Q13/206; manufacturing reflecting surfaces using insulating material for supporting the reflecting surface H01Q15/142
• CPC Class Codes: H01Q 1/523 between antennas of an array
• CPC Class Codes: H01Q 1/526 Electromagnetic shields
• CPC Class Codes: H01Q 15/006 Selective devices having photonic band gap materials or materials of which the material properties are frequency dependent, e.g. perforated substrates, high-impedance surfaces
• CPC Class Codes: H01Q 21/28 Combinations of substantially independent non-interacting antenna units or systems multiple beam H01Q25/00
• CPC Class Codes: H01Q 3/44 varying the electric or magnetic characteristics of reflecting, refracting, or diffracting devices associated with the radiating element
• CPC Class Codes: H01Q 7/08 Ferrite rod or like elongated core
• CPC Class Codes: H01Q 9/045 with particular feeding means for circular polarisation H01Q9/0428
• CPC Class Codes: Y10T 29/49004 including measuring or testing of device or component part

Abstract

A magnetic permeability enhanced metamaterial is used to enhance the antenna array of a Multiple Input Multiple Output (MIMO) communication system. A rectangular patch antenna array is formed including a stack of a plurality of unit cells, where each unit cell includes an inductive loop of magnetic permeability enhanced metamaterials embedded in a host dielectric substrate. The use of such metamaterials permits the antenna arrays to be made smaller, and have less mutual coupling, when using a metamaterial substrate. The measured channel capacities of the antenna arrays are similar for the metamaterial and conventional substrates; however, the capacity improvement when using MIMO relative to single antenna communication systems is greater for antennas on metamaterial substrates.

Claims

1. A wireless transmission apparatus comprising a rectangular patch antenna array including multiple antenna elements mounted on a substrate comprising a plurality of unit cells having rectangular inductive spiral loops embedded uniformly and uni-directionally within a host dielectric substrate so as to form a magnetic permeability enhanced metamaterial, said unit cells being uniformly stacked on each other to form a three-dimensional resonance structure that is oriented orthogonally to a magnetic field of said antenna array, where dimensions of said rectangular inductive spiral loops are selected whereby said metamaterial has a resonance frequency that matches a resonance frequency of said multiple antenna elements of said antenna array.

2. The apparatus of claim 1, wherein the dimensions of said rectangular inductive spiral loops of said unit cells are tuned whereby the resonance frequency of said metamaterial matches the resonance frequency of said multiple elements of said antenna array.

3. The apparatus of claim 1, wherein each antenna element is spaced from each other antenna element by a spacing of λ

/20 in an azimuthal plane of the substrate, where λ

=c/f, where c is the speed of light and f is the resonance frequency of the substrate.

4. The apparatus of claim 1 wherein the wireless transmission apparatus is a wireless local area network (LAN).

5. The apparatus of claim 1 wherein the wireless transmission apparatus is a personal wireless communications device.

6. A rectangular patch antenna array including multiple antenna elements mounted on a substrate comprising a plurality of unit cells having rectangular inductive spiral loops embedded uniformly and uni-directionally within a host dielectric substrate so as to form a magnetic permeability enhanced metamaterial, said unit cells being uniformly stacked on each other to form a three-dimensional resonance structure that is oriented orthogonally to a magnetic field of said antenna array, where dimensions of said rectangular inductive spiral loops are selected whereby said metamaterial has a resonance frequency that matches a resonance frequency of said multiple antenna elements of said antenna array.