Novel directional coupler for high-frequency electric signals

Claim 2

A directional coupler for high-frequency waves comprising, on a piezoelectric member, an input transducer to which a highfrequency wave is applied and a number of output transducers collecting the corresponding wave transmitted to the surface of the piezoelectric member, and a number of conductive strips disposed between the input transducer and the output transducers at an angle to the direction of the high-frequency wave in the piezoelectric member, characterised in that it comprises means producing an electron beam, means causing the beam to strike regions of said piezoelectric member, means to endow said regions with the property of being electrically insulating, said regions being made conductive at the place of impact owing to free charge carriers being produced therein, means for chopping the beam into pulses, tHe impact of the beam on each region occuring during one of the pulses, and means causing the beam to periodically scan the regions at a period less than the recombination time of the free charge carriers.

Claim 3

A directional coupler according to claim 1, characterised in that said means to endow said regions with the property of being electrically insulating is a layer of an electrically insulating material covering said piezoelectric member on that of its faces struck by the electron beam.

Claim 4

A directional coupler according to claim 1, characterised in that each conductive strip is made up of two portions of metal conductors separated from one another and a region which is made conductive by electron bombardment and is in contact with the aforementioned two portions.

Claim 5

A directional coupler according to claim 3, characterised in that the piezoelectric member is made up of two separate pieces placed side by side and connected transversely to the aforementioned portions, each of the two portions forming one of the strips being at least partly disposed on one of the aforementioned two pieces.

Claim 6

A directional coupler according to claim 4, characterised in that the two pieces making up the piezoelectric member are made of the same material.

Claim 7

A directional coupler according to claim 4, characterised in that the two pieces making up the piezoelectric member are made of different materials.

Claim 8

A directional coupler for high-frequency waves comprising, on a piezoelectric member, an input transducer to which a high-frequency wave is applied and a number of output transducers collecting the corresponding wave transmitted to the surface of the piezoelectric member, and a number of conductive strips disposed between the input transducer and the output transducers at an angle to the direction of the high-frequency wave in the piezoelectric member, characterised in that it comprises means producing an electron beam, means causing the beam to strike regions of said piezoelectric member, means to endow said regions with the property of being electrically insulating, said regions being made conductive at the place of impact owing to free charge carriers being produced therein, means for chopping the beam into pulses, the impact of the beam on each region occuring during one of the pulses, and means causing the beam to periodically scan the regions at a period less than the recombination time of the free charge carriers, the device also comprising means associated with the deflecting means for modifying the spacing between the regions and thus enabling the coupler to be used for high-frequency waves having varying frequencies.

Claim 9

A directional coupler for high-frequency waves comprising, on a piezoelectric member, an input transducer to which a high-frequency wave is applied and a number of output transducers collecting the corresponding wave transmitted to the surface of the piezoelectric member, and a number of conductive strips disposed between the input transducer and the output transducers at an angle to the direction of the high-frequency wave in the piezoelectric member, characterised in that it comprises means producing an electron beam, means causing the beam to strike regions of said piezoelectric member, means to endow said regions with the property of being electrically insulating, said regions being made conductive at the place of impact owing to free charge carriers being produced therein, means for chopping the beam into pulses, the impact of the beam on each region occuring during one of the pulses, and means causing the beam to periodically scan the regions at a period less than the recombination time of the free charge carriers, the device also comprising means associated with the deflecting means for modifying the spacing between the regions and thus enabling the coupler to be used for high-frequency waves having varying frequencies.

Claim 10

A directional coupler for high-frequency waves comprising, on a piezoelectric member, an input transducer to which a high-frequency wave is applied and a number of output transducers collecting the corresponding wave transmitted to the surface of the piezoelectric member, and a number of conductive strips disposed between the input transducer and the output transducers at an angle to the direction of the high-frequency wave in the piezoelectric member, characterised in that it comprises means producing an electron beam, means causing the beam to strike regions of said piezoelectric member, means to endow said regions with the property of being electrically insulating, said regions being made conductive at the place of impact owing to free charge carriers being produced therein, means for chopping the beam into pulses, the impact of the beam on each region occuring during one of the pulses, and means causing the beam to periodically scan the regions at a period less than the recombination time of the free charge carriers, the device also comprising means for modifying the number of the aforementioned regions and consequently modifying the coupling ratio of each output transducer with the input transducer.

Claim 11

A directional coupler for high-frequency waves comprising, on a piezoelectric member, an input transducer to which a high-frequency wave is applied and a number of output transducers collecting the corresponding wave transmitted to the surface of the piezoelectric member, and a number of conductive strips disposed between the input transducer and the output transducers at an angle to the direction of the high-frequency wave in the piezoelectric member, characterised in that it comprises means producing an electron beam, means causing the beam to strike regions of said piezoelectric member, means to endow said regions with the property of being electrically insulating, said regions being made conductive at the place of impact owing to free charge carriers being produced therein, means for chopping the beam into pulses, the impact of the beam on each region occuring during one of the pulses, and means causing the beam to periodically scan the regions at a period less than the recombination time of the free charge carriers, the device also comprising means for modifying the number of the aforementioned regions and consequently modifying the coupling ratio of each output transducer with the input transducer.