# US 11,909,112 B2 · Sideband-free space-time-coding metasurface antennas

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- Number: US 11,909,112 B2
- Document ID: US11909112B2
- Status: Granted
- Kind: B2
- Application number: 17/848,424
- Filed: 2022-06-24
- Published: 2023-12-28
- Granted: 2024-02-20
- Earliest claimed: 2022-06-24
- Assignees: City University of Hong Kong
- Applicants: City University of Hong Kong
- Inventors: Gengbo Wu; Junyan Dai; Chi Hou Chan
- Web page: https://patentgrep.com/patent/US11909112B2

## CPC

- H01Q 13/28: comprising elements constituting electric discontinuities and spaced in direction of wave propagation, e.g. dielectric elements or conductive elements forming artificial dielectric
- H01Q 15/0086: {said selective devices having materials with a synthesized negative refractive index, e.g. metamaterials or left-handed materials}
- H01Q 1/2283: {mounted in or on the surface of a semiconductor substrate as a chip-type antenna or integrated with other components into an IC package}
- H01Q 3/44: varying the electric or magnetic characteristics of reflecting, refracting, or diffracting devices associated with the radiating element
- 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}
- H01Q: ANTENNAS, i.e. RADIO AERIALS (radiators or antennas for microwave heating H05B6/72)

## Abstract

A self-filtering, space-time coding, waveguide-driven metasurface antenna includes at least first and second metal layers, and first dielectric layer between the first and second metal layers. A series of vias is formed in the first dielectric layer. A substrate integrated waveguide (SIW) is formed from the first and second metal layers and from the metal vias in the first dielectric layer. A series of meta-atoms is formed in the first metal layer, each meta-atom including a slot cooperating with two switching elements for switching the meta-atom between an on and off state. Each meta-atom behaves as a magnetic dipole antenna element that radiates electromagnetic waves into free space. In this manner, the propagating guided waves inside the substrate integrated waveguide are converted and molded into arbitrary selected out-of-plane free-space waves in both a frequency domain and a momentum domain.

## Claims

### Claim 1

A self-filtering, space-time coding, waveguide-driven metasurface antenna comprising:
at least first and second metal layers;
a first dielectric layer interposed between the first and second metal layers;
a plurality of metal vias formed in the first dielectric layer;
a substrate integrated waveguide (SIW) formed from the first and second metal layers and from the metal vias in the first dielectric layer;
a plurality of meta-atoms formed in the first metal layer, each meta-atom including a slot cooperating with two switching elements for switching a meta-atom between an on and off state, wherein each meta-atom behaves as a magnetic dipole antenna element that radiates electromagnetic waves into free space such that propagating guided waves inside the substrate integrated waveguide are converted and molded into arbitrary selected out-of-plane free-space waves in both a frequency domain and a momentum domain.

### Claim 2 (depends on 1)

The self-filtering, space-time coding, waveguide-driven metasurface antenna of claim 1, wherein the plurality of meta-atoms is formed in first and second rows.

### Claim 3 (depends on 2)

The self-filtering, space-time coding, waveguide-driven metasurface antenna of claim 2, wherein a period for the first row of meta-atoms is offset from a period for the second row of meta-atoms.

### Claim 4 (depends on 1)

The self-filtering, space-time coding, waveguide-driven metasurface antenna of claim 1, further comprising control lines.

### Claim 5 (depends on 1)

The self-filtering, space-time coding, waveguide-driven metasurface antenna of claim 1, wherein the switching elements are PIN diodes.

### Claim 6 (depends on 1)

The self-filtering, space-time coding, waveguide-driven metasurface antenna of claim 1, further comprising a controller to switch the switching elements between a coupling and a non-coupling state in a predetermined sequence to create the arbitrary free-space waves.

### Claim 7 (depends on 6)

The self-filtering, space-time coding, waveguide-driven metasurface antenna of claim 6, wherein the controller is an FPGA.

### Claim 8 (depends on 1)

The self-filtering, space-time coding, waveguide-driven metasurface antenna of claim 1, wherein unwanted higher-order harmonics cannot fulfill phase-matching conditions and are prohibited inside the SIW.

### Claim 9 (depends on 1)

The self-filtering, space-time coding, waveguide-driven metasurface antenna of claim 1, wherein a radiating state of each meta-atom is configured to be independently controlled by switching the switching elements of each meta-atom in a predetermined coding sequence.

### Claim 10 (depends on 9)

The self-filtering, space-time coding, waveguide-driven metasurface antenna of claim 9, further comprising a processor to supply the predetermined coding sequence.