Contactless radiofrequency device featuring several antennas and related antenna selection circuit

• US 20080068132A1
• Filed: 05/14/2007
• Published: 03/20/2008
• Est. Priority Date: 05/16/2006
• Status: Abandoned Application

• Current Assignee: Ask S.A. (Paragon Group Limited)
• Original Assignee: Ask S.A. (Paragon Group Limited)
• Inventors: Grasset, Yannick, Sabbah, Elias, Kayanakis, Georges
• Application Number:
  US11/798,456
• Publication Number:
  US 20080068132A1
• Time in Patent Office: Days
• US Class Current: 340/10.1
• CPC Class Codes: G06K 19/0724 the arrangement being a circuit for communicating at a plurality of frequencies, e.g. for managing time multiplexed communication over at least two antennas of different types
• CPC Class Codes: G06K 19/07766 comprising at least a second communication arrangement in addition to a first non-contact communication arrangement
• CPC Class Codes: H01Q 1/2225 used in active tags, i.e. provided with its own power source or in passive tags, i.e. deriving power from RF signal
• CPC Class Codes: H01Q 21/24 Combinations of antenna units polarised in different directions for transmitting or receiving circularly and elliptically polarised waves or waves linearly polarised in any direction circularly polarised patch antennas H01Q9/0428; circularly polarised horns H01Q13/0241; cross-polarised horns H01Q13/0258; polarisation converters H01Q15/242; cross-polarised rear feeds H01Q19/136; crossed polarisation dual antenna H01Q25/001
• CPC Class Codes: H01Q 9/42 with folded element, the folded parts being spaced apart a small fraction of the operating wavelength
• CPC Class Codes: H04B 5/0062 in RFID [Radio Frequency Identification] Systems
• CPC Class Codes: H04B 5/02 using transceiver
• CPC Class Codes: H04B 5/48 Transceivers
• CPC Class Codes: H04B 5/77 for interrogation

Abstract

The invention relates to an integrated circuit for contactless radiofrequency device connected to a first antenna and to a second antenna designed to receive a radiofrequency signal coming from a reader. According to a main characteristic, the integrated circuit includes a first rectifier circuit and a second rectifier circuit to rectify each radiofrequency signal received from the first antenna and the second antenna, respectively, so as to produce two positive output voltages V1 and V2, the rectifier circuits being mounted in parallel in order to select an output voltage value that corresponds to the maximum voltage value between V1 and V2.

Claims

1. Circuit inté

gré

(12) pour dispositif sans contact radiofré

quence connecté

à

une premiè

re antenne (14) et à

une seconde antenne (18) é

tant destiné

es à

recevoir un signal radiofré

quence en provenance d'"'"'un lecteur,

caracté

risé

en ce que ledit circuit inté

gré

(12) comprend un premier circuit redresseur (40) et un second circuit redresseur (50) pour redresser chaque signal radiofré

quence recu respectivement de ladite premiè

re antenne (14) et de ladite seconde antenne (18), de facon à

produire deux tensions de sortie positives V1 et V2, lesdits circuits redresseur (40 et 50) é

tant monté

s en parallè

le de facon à

sé

lectionner une valeur de tension de sortie qui correspond à

la valeur de tension maximale entre V1 et V2.

2-12. -12. (canceled)