Very high frequency passive transponder, in particular a UHF transponder, with a voltage multiplier or booster at the entry of its logic circuit

• US 20060087301A1
• Filed: 10/07/2005
• Published: 04/27/2006
• Est. Priority Date: 10/07/2004
• Status: Active Grant

• Current Assignee: EM Microelectronic - Marin SA (The Swatch Group AG)
• Original Assignee: EM Microelectronic - Marin SA (The Swatch Group AG)
• Inventors: Pardoen, Matthijs, Desjeux, Olivier
• Granted Patent: US 7,515,050 B2
• Time in Patent Office: Days
• US Class Current: 323/282
• CPC Class Codes: G06K 19/0713 the arrangement including a power charge pump
• CPC Class Codes: G06K 19/0723 the record carrier comprising an arrangement for non-contact communication, e.g. wireless communication circuits on transponder cards, non-contact smart cards or RFIDs

Abstract

The passive transponder comprises an antenna (2) connected to an integrated circuit (6) the analogue part of which includes a passive voltage rectifier (8) supplying a rectified voltage (V_DC1) and an active multiplier or booster (16) for said rectified voltage which is formed by a capacitor (C2) switched to a relatively low frequency, for example 1 MHz, by means of switches formed by transistors (18 to 21) controlled using an oscillator (24).

Claims

1. Passive transponder arranged for receiving a very high frequency electromagnetic signal, particularly in the UHF range, and including an antenna and an integrated circuit connected to said antenna, said integrated circuit including analogue means for rectifying the alternating input voltage of said received electromagnetic signal and for multiplying or boosting said alternating input voltage, said rectifying and multiplying means powering a logic circuit of said integrated circuit, wherein said alternating input voltage rectifying and multiplying or boosting means include a passive rectifier supplying a rectified voltage and an active voltage multiplier or booster arranged downstream of the passive rectifier, said voltage multiplier or booster including at least one capacitor switched to a lower frequency than said frequency of said received signal.

2. Transponder according to claim 1, wherein said voltage multiplier or booster includes transistors forming current switches, said transistors being switched at a relatively low frequency.

3. Transponder according to claim 1, including an oscillator integrated in said integrated circuit and used for clocking said logic circuit and generating control pulses for said voltage multiplier or booster.

4. Transponder according to claim 1, wherein said voltage multiplier is a doubler of said rectifier voltage by said passive rectifier.

5. Transponder according to claim 2, including an oscillator integrated in said integrated circuit and used for clocking said logic circuit and generating control pulses for said voltage multiplier or booster.