Reconfigurable radiating phase-shifting cell based on complementary slot and microstrip resonances

• US 9,647,336 B2
• Filed: 09/14/2012
• Issued: 05/09/2017
• Est. Priority Date: 09/14/2011
• Status: Active Grant

• Current Assignee: Centre National De La Recherche Scientifique, Institut National des Sciences Appliquées de Rennes, Thales SA
• Original Assignee: Centre National De La Recherche Scientifique, Institut National des Sciences Appliquées de Rennes, Thales SA
• Inventors: Legay, Herve, Girard, Etienne, Bresciani, Daniele, Gillard, Raphael, Salti, Hassan, Makdissy, Tony, Fourn, Erwan
• Primary Examiner(s): Levi, Dameon E
• Assistant Examiner(s): ISLAM, HASAN Z
• Application Number:
  US13/618,506
• Publication Number:
  US 20130241770A1
• Time in Patent Office: 1,698 Days
• Field of Search: 343909
• CPC Class Codes: H01Q 3/36 with variable phase-shifters
• CPC Class Codes: H01Q 3/46 Active lenses or reflecting arrays

Abstract

A radiating phase-shifting cell is designed to favour the excitation of an equivalent resonance of the “slot” type in a first part of the phase cycle, and to favour an equivalent resonance of the “microstrip” type in a second part of the phase cycle. This property notably allows the bandwidth of the phase-shifting cells to be optimized. A phase range of 360° can in effect be segmented into two sub-ranges of around 180°. This segmentation into two sub-ranges is made possible by the complementarity of the resonant modes of the slot or microstrip type. The radiating phase-shifting cell is notably applicable to reflector arrays for an antenna designed to be installed on a space craft such as a telecommunications satellite or on a terrestrial terminal for satellite telecommunications or broadcasting systems.

Claims

1. A radiating phase-shifting cell comprising:

a plurality of conducting elements formed on a surface of a substrate, above and separated from a ground plane and situated on a periphery, each conducting element being positioned symmetrically around and connected to at least one central conducting element and to neighbouring conducting elements on the periphery by controlled variable capacitive loads, the conducting elements being separated by radially-oriented slots,

an arrangement of the slots forming an equivalent resonator whose electrical shape configures a phase-shift applied to a wave to be reflected, wherein the radiating phase-shifting cell comprises the controlled variable capacitive loads, which are capable of varying at least one of an electrical length and of an electrical width of the slots,

wherein the conducting elements and the controlled variable capacitive loads are arranged so that, according to at least a first configuration of the controlled variable capacitive loads, a surface conductor of microwave signals is formed to create a resonator that is predominantly inductive, and so that, according to at least a second configuration, the slots are formed around the at least one central conducting element to create a resonator that is predominantly capacitive, and

a conducting surface formed by the plurality of conducting elements arranged around the at least one central conducting element and being separated from each other by the slots to not completely encircle the at least one central conducting element.

2. The radiating phase-shifting cell according to claim 1, wherein the conducting elements take a form of a cross with four branches aligned in several rows, the crosses belonging to two successive rows being offset with respect to one another, the cross being connected by means of controlled variable capacitive loads.

3. The radiating phase-shifting cell according to claim 1, wherein the conducting surface is formed by conducting strips surrounded by annular slots, the conducting strips being connected by capacitive loads capable of modifying at least one of the electrical length and the electrical width of interconnection slots of the annular slots.

4. The radiating phase-shifting cell according to claim 1, wherein, when the radiating phase-shifting cell is in the first configuration, the controlled variable capacitive loads connecting the peripheral conducting elements together are activated, the controlled variable capacitive loads connecting the central conducting element to the peripheral conducting elements being disabled, to form a resonant slot whose main contribution is equivalent to that of a parallel LC circuit.

5. The radiating phase-shifting cell according to claim 4, wherein the controlled variable capacitive loads connecting the peripheral conducting elements together are designed to take multiple values between two end values to be able to make dimensions of an equivalent resonant slot vary progressively as a function of the values.

6. The radiating phase-shifting cell according to claim 1, wherein, when the radiating phase-shifting cell is in the second configuration, the controlled variable capacitive loads connecting the peripheral conducting elements together are disabled, the controlled variable capacitive loads connecting the central conducting element to the peripheral conducting elements being activated, to form a resonant microstrip whose main contribution is equivalent to a series LC circuit.

7. The radiating phase-shifting cell according to claim 6, wherein the controlled variable capacitive loads connecting the central conducting element to the peripheral conducting elements are designed to take multiple values between two end values to be able to vary dimensions of an equivalent resonant microstrip progressively as a function of the values.

8. The radiating phase-shifting cell according to claim 1, wherein the controlled variable capacitive loads connecting the central conducting element to the peripheral conducting elements are designed to vary independently from a value of the loads connecting the peripheral conducting elements together, in such a manner that a phase-shift range applied to an incident wave is decomposed into two intervals of phase-shift, the phase-shifts applied in the first interval being obtained with a configuration of a resonant slot type, the phase-shifts applied in the second interval being obtained with a configuration of a resonant microstrip type.

9. The radiating phase-shifting cell according to claim 1, wherein the controlled variable capacitive loads and dimensions of the conducting elements are determined such that a configuration of the radiating phase-shifting cell allowing a corresponding phase-shift to be applied to a first end of a phase-shift range is identical to configuration of the radiating phase-shifting cell allowing a corresponding phase-shift to be applied to a second end of the phase-shift range.

10. The radiating phase-shifting cell according to claim 1, wherein a phase-shift range is 360°

.

11. The radiating phase-shifting cell according to claim 1, wherein the conducting elements, the slots and the controlled variable capacitive loads are disposed on the cell according to a center of symmetry placed in the center of the cell.

12. The radiating phase-shifting cell according to claim 1, wherein the controlled variable capacitive loads are diodes, Micro-Electro-Mechanical Systems (MEMS), or ferroelectric capacitors.

13. A reflector array comprising a plurality of radiating phase-shifting cells according to claim 1, the radiating phase shifting cells forming a reflecting surface of the reflector array.

14. An antenna comprising a reflector array according to claim 13.

15. A reflector array antenna comprising:

a plurality of radiating phase shifting cells forming a reflecting surface of the reflector array, wherein each said radiating phase shifting cell comprises a plurality of conducting elements formed on a surface of a substrate, above and separated from a ground plane and situated on a periphery,

each conducting element being positioned around and connected to at least one central conducting element and to neighboring conducting elements on the periphery by controlled variable capacitive loads,

the plurality of conducting elements being separated by slots, an arrangement of the slots forming an equivalent resonator whose electrical shape configures a phase-shift applied to a wave to be reflected,

wherein each said radiating phase shifting cell comprises the controlled variable capacitive loads, which are capable of varying at least one of an electrical length and of an electrical width of the slots,

the plurality of conducting elements, the slots and the controlled variable capacitive loads being disposed on the cell according to a center of symmetry placed in the center of the cell and being arranged so that, according to at least a first configuration of the controlled variable capacitive loads, a surface conductor of microwave signals is formed to create a resonator that is predominantly inductive, and so that, according to at least a second configuration, the slots are formed around the at least one central conducting element to create a resonator that is predominantly capacitive, and

a conducting surface formed by the plurality of conducting elements surrounded by the slots surrounding the at least one central conducting element and being separated from each other by portions of the slots having a radial orientation with respect to the at least one central conducting element.