Reconfigurable Radiating Phase-Shifting Cell Based on Complementary Slot and Microstrip Resonances

• US 20130241770A1
• Filed: 09/14/2012
• Published: 09/19/2013
• 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 Toulouse, Thales SA
• Inventors: LEGAY, Herve, GIRARD, Etienne, BRESCIANI, Daniele, GILLARD, Raphael, SALTI, Hassan, MAKDISSY, Tony, FOURN, Erwan
• Granted Patent: US 9,647,336 B2
• Time in Patent Office: Days
• US Class Current: 342/372
• 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 the surface of a substrate, above and separated from a ground plane, the said conducting elements being separated by slots, the arrangement of the slots forming an equivalent resonator whose electrical shape configures the phase-shift applied to a wave to be reflected, wherein the cell comprises controlled variable loads capable of varying the electrical length and/or width of the said slots, the conducting elements and the controlled variable loads arranged so that, according to at least a first configuration of the said loads, a surface conductor of microwave signals is formed in order to create a resonator that is predominantly inductive, and so that, according to at least a second configuration, a slot is formed around at least one central conducting element in order to create a resonator that is predominantly capacitive, the said conducting surface being formed by a plurality of conducting elements surrounding the said central conducting element.

2. The radiating phase-shifting cell according to claim 1, in which the conducting elements forming the conducting surface are situated on the periphery, each of the said peripheral conductors being connected to the central conductor and to the neighbouring peripheral conductors by means of controlled capacitive loads.

3. The radiating phase-shifting cell according to claim 1, in which the conducting elements take the 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.

4. The radiating phase-shifting cell according to claim 1, in which the said conducting surface is formed by conducting strips surrounded by annular slots, the said strips being connected by capacitive loads capable of modifying the electrical length and/or width of the interconnection slots of the said annular slots.

5. The radiating phase-shifting cell according to claim 2, in which, when the cell is in the first configuration, the loads connecting the peripheral conducting elements together are activated, the loads connecting the central conducting element to the peripheral conducting elements being disabled, so as to form a resonant slot whose main contribution is equivalent to that of a parallel LC circuit.

6. The radiating phase-shifting cell according to claim 5, in which the loads connecting the peripheral conducting elements together are designed to take multiple values between two end values in order to be able to make the dimensions of the equivalent resonant slot vary progressively as a function of the said values.

7. The radiating phase-shifting cell according to claim 2, in which, when the cell is in the second configuration, the loads connecting the peripheral conducting elements together are disabled, the loads connecting the central conducting element to the peripheral conducting elements being activated, so as to form a resonant microstrip whose main contribution is equivalent to that of a series LC circuit.

8. The radiating phase-shifting cell according to claim 7, in which the loads connecting the central conducting element to the peripheral conducting elements are designed to take multiple values between two end values in order to be able to vary the dimensions of the equivalent resonant microstrip progressively as a function of the said values.

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

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

11. The radiating phase-shifting cell according to claim 1, in which the phase-shift range is 360°

.

12. The radiating phase-shifting cell according to claim 1, in which the conducting elements, the slots and the capacitive loads are disposed on the cell according to a centre of symmetry placed in the centre of the cell.

13. The radiating phase-shifting cell according to claim 1, in which the capacitive loads are diodes, MEMS, or ferroelectric capacitors.

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

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