RF energy harvester

• US 9,966,801 B2
• Filed: 08/04/2017
• Issued: 05/08/2018
• Est. Priority Date: 08/09/2013
• Status: Active Grant

• Current Assignee: Drayson Technologies (Europe) Limited
• Original Assignee: Drayson Technologies (Europe) Limited
• Inventors: Mitcheson, Paul David, Lucyszyn, Stepan, Rangel, Manuel Pinuela, Yates, David Christopher
• Primary Examiner(s): Cavallari, Daniel
• Application Number:
  US15/669,023
• Publication Number:
  US 20170358957A1
• Time in Patent Office: 277 Days
• CPC Class Codes: H01Q 1/248 provided with an AC/DC converting device, e.g. rectennas
• CPC Class Codes: H01Q 5/364 Creating multiple current paths
• CPC Class Codes: H01Q 9/0464 Annular ring patch
• CPC Class Codes: H02J 50/001 Energy harvesting or scavenging
• CPC Class Codes: H02J 50/005 Mechanical details of housing or structure aiming to accommodate the power transfer means, e.g. mechanical integration of coils, antennas or transducers into emitting or receiving devices
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/20 using microwaves or radio frequency waves
• CPC Class Codes: H02J 50/27 characterised by the type of receiving antennas, e.g. rectennas
• CPC Class Codes: H02J 50/402 the two or more transmitting or the two or more receiving devices being integrated in the same unit, e.g. power mats with several coils or antennas with several sub-antennas
• CPC Class Codes: H02J 50/80 involving the exchange of data, concerning supply or distribution of electric power, between transmitting devices and receiving devices
• CPC Class Codes: H02J 7/00034 Charger exchanging data with an electronic device, i.e. telephone, whose internal battery is under charge

Abstract

An antenna apparatus for harvesting ambient radio frequency, RF, energy, comprises one or more RF antenna components arranged to receive RF energy. The antenna components comprise a plurality of frequency filtering components, each filtering a respective frequency band of the received RF energy. A rectifying circuit is arranged to convert a variable electrical signal received at an input from an associated antenna, into a direct current electrical signal for supplying to an electrical energy storage unit. A power management module has an input arranged to receive the direct current and control supply of the direct current to the electrical energy storage unit. The rectifying circuit comprises a plurality of transmission lines, and the input of the rectifying circuit and the input of the power management module are connected via the transmission lines. The power management module is arranged at least partially within a boundary defined by the transmission lines.

Claims

1. An antenna apparatus (101) for use in harvesting ambient radio frequency, RF, energy and connectable to a rectifier (103), the antenna apparatus (101) comprising:

a substrate comprising a first side and a second side opposing the first side;

a radiating patch (110) formed on the first side of the substrate; and

a ground plane (112) formed on the second side of the substrate,

wherein the radiating patch (110) is arranged to receive RF energy for producing electricity,

wherein the radiating patch (110) comprises first and second filtering notches (110a, 110b) each being arranged to modify a return loss and bandwidth of the antenna apparatus (101) with respect to a targeted frequency of the received RF energy,

wherein the ground plane (112) comprises a ground plane notch (112a), and

wherein the ground plane notch (112a) is arranged to filter harmonics created by the rectifier (103).

2. The antenna apparatus according to claim 1, wherein the return loss and bandwidth of the antenna apparatus (101) modified by the first and second filtering notches (110a, 110b) are determined according to the dimensions of the first and second filtering notches (110a, 110b), and wherein the first and second filtering notches (110a, 110b) are formed in or on the one or more RF antenna components at positions associated with one or more resonant frequencies of the radiating patch (110) within which they are formed.

3. The antenna apparatus according to claim 1, wherein the targeted frequency of the received RF energy lies in one or more known electromagnetic radiation frequency bands, and wherein the one or more known electromagnetic radiation frequency bands include one or more of GSM900, GSM1800, 3G, and 4G.

4. The antenna apparatus according to claim 1, wherein the radiating patch (110) is arranged to receive a first frequency range and the radiating patch (110) is circular-shaped.

5. The antenna apparatus according to claim 4, wherein the first filtering notch (110a) is a curved feature formed concentrically in or on the circular-shaped radiating patch (110), the first filtering notch (110a) being arranged for filtering one or more frequencies within the first frequency range.

6. The antenna apparatus according to claim 5, wherein the first filtering notch (110a) is:

positioned at a distance from the centre of the circular-shaped radiating patch of between λ

g/12 and λ

g/16;

between λ

g/6 and λ

g/15 in length; and

between λ

g/18.5 to λ

g/24.2 in width, wherein

λ

g is a wavelength at a centre frequency of the respective frequency band associated with the respective filtering notch (110a).

7. The antenna apparatus according to claim 5, wherein the second filtering notch (110b) is a curved feature formed concentrically in or on the circular-shaped radiating patch (110) arranged for filtering one or more frequencies within the first frequency range, wherein the one or more frequencies filtered by the second filtering notch (110b) differ to the one or more frequencies filtered by the first filtering notch (110a).

8. The antenna apparatus according to claim 6, wherein the second filtering notch (110b) is:

positioned at a distance from the centre of the circular-shaped radiating patch (110a) of between λ

g/12 to λ

g/24;

between λ

g/4.5 to λ

g/5.7 in length; and

between λ

g/18.5 to λ

g/24.2 in width, wherein

λ

g is a wavelength at a centre frequency of the respective frequency band associated with the respective filtering notch (110b).

9. The antenna apparatus according to claim 4, wherein the ground plane is arranged to define the radiation pattern of the antenna apparatus (101).

10. The antenna apparatus according to claim 9, wherein the ground plane notch (112a) is for filtering one or more frequencies within a second frequency range.

11. The antenna apparatus according to claim 10, wherein the ground plane notch (112a) is U-shaped.

12. The antenna apparatus according to claim 10, wherein the ground plane notch (112a) is formed in or on the ground plane:

at a distance from a nearest edge of the circular-shaped radiating patch of between λ

g/5.4 to λ

g/8.1;

between λ

g/7.4 to λ

g/10.5 in length; and

between λ

g/15.2 to λ

g/24.2 in width, wherein λ

g is a wavelength at a centre frequency of the respective frequency band associated with the respective frequency filtering component.

13. The antenna apparatus according to any of claim 9, wherein the substrate is flexible.