Short-distance contactless communication apparatus and method thereof

Abstract

A short-distance contactless communication apparatus includes a chip. The chip includes: a signal receiving port capable of receiving a modulation signal from the outside of the chip; a first receiver capable of operating under a proximity coupling device mode and/or a proximity inductively coupled card mode; and an adjusting device separate from the first receiver for tracking an envelope of the modulation signal on the signal receiving port of the chip and scaling the modulation signal on the signal receiving port of the chip proportionally during data communication phase of the short-distance contactless communication apparatus. The scaled modulation signal on the signal receiving port of the chip is received by the first receiver, and a peak voltage level of the scaled modulation signal on the signal receiving port of the chip falls within a predetermined voltage range.

What is claimed is: 
     
         1 . A short-distance contactless communication apparatus, comprising a chip, and the chip comprises:
 a signal receiving port, capable of receiving a modulation signal from the outside of the chip;   a first receiver, coupled to the signal receiving port of the chip, capable of operating under a proximity coupling device (PCD) mode and/or a proximity inductively coupled card (PICC) mode; and   an adjusting device separate from the first receiver, coupled to the signal receiving port of the chip, for tracking an envelope of the modulation signal on the signal receiving port of the chip and scaling the modulation signal on the signal receiving port of the chip proportionally during data communication phase of the short-distance contactless communication apparatus;   wherein the scaled modulation signal on the signal receiving port of the chip is received by the first receiver, and a peak voltage level of the scaled modulation signal on the signal receiving port of the chip falls within a predetermined voltage range.   
     
     
         2 . The short-distance contactless communication apparatus of  claim 1 , wherein the adjusting device presently scales the peak voltage level of the modulation signal proportionally on the signal receiving port of the chip when the short-distance contactless communication apparatus receives the modulation signal via the signal receiving port. 
     
     
         3 . The short-distance contactless communication apparatus of  claim 1 , wherein the adjusting device scales the peak voltage level of the modulation signal proportionally on the signal receiving port to substantially equal a predetermined voltage level in the predetermined voltage range. 
     
     
         4 . The short-distance contactless communication apparatus of  claim 1 , wherein the adjusting device scales the peak voltage level of the modulation signal proportionally on the signal receiving port to fall within the predetermined voltage range during the PCD mode of the short-distance contactless communication apparatus, and the modulation signal is an in-band blocker signal or a load modulation signal. 
     
     
         5 . The short-distance contactless communication apparatus of  claim 1 , which is an integrated NFC (Near field communication) device. 
     
     
         6 . The short-distance contactless communication apparatus of  claim 1 , wherein the modulation signal is an ASK (Amplitude-shift keying) signal during data communication phase, and
 Wherein, during voltage regulation phase, the modulation signal is a continuous wave (CW) signal having an oscillating frequency substantially equal to 13.56 MHz and is adjusted to fall within the predetermined voltage range.   
     
     
         7 . The short-distance contactless communication apparatus of  claim 1 , the chip further comprising:
 a second receiver, coupled to the signal receiving port of the chip, capable of operating under a PCD mode or a PICC mode.   
     
     
         8 . The short-distance contactless communication apparatus of  claim 1 , wherein the adjusting device scales the peak voltage level of the modulation signal proportionally on the signal receiving port of the chip to fall within the predetermined voltage range during the PICC mode of the short-distance contactless communication apparatus, and the modulation signal is a receiving ASK (Amplitude-shift keying) signal of the short-distance contactless communication apparatus. 
     
     
         9 . The short-distance contactless communication apparatus of claim  1 , further comprising:
 a baseband processor, coupled to the first receiver and the adjusting device; and   
       wherein the adjusting device comprises:
 a programmable impedance component, having a first terminal coupled to the signal receiving port and a second terminal coupled to a reference voltage, for providing an impedance between the signal receiving port and the reference voltage according to an adjusting signal; and 
 an envelope detector, coupled to the signal receiving port and the baseband processor, for detecting an envelope of the modulation signal to generate a detecting signal; 
 
       wherein the baseband processor receives the detecting signal and accordingly generates the adjusting signal to adjust the impedance of the programmable impedance component such that the peak voltage level of the modulation signal on the signal receiving port falls within the predetermined voltage range. 
     
     
         10 . The short-distance contactless communication apparatus of  claim 9 , wherein the baseband processor adjusts the impedance of the programmable impedance component such that the peak voltage level of the modulation signal on the signal receiving port of the chip substantially equals a predetermined voltage level in the predetermined voltage range. 
     
     
         11 . The short-distance contactless communication apparatus of  claim 9 , further comprising:
 a fixed resistor coupled to the signal receiving port of the chip;   wherein the programmable impedance component comprises a programmable resistor circuit having a first terminal coupled to the signal receiving port and a second terminal coupled to a ground;   wherein the resistance of the programmable resistor circuit is adjusted according to the peak voltage level at the input of the envelope detector, and the adjustment of the programmable resistor circuit continues until the peak voltage at the input of the envelope detector is within the predetermined voltage range.   
     
     
         12 . The short-distance contactless communication apparatus of  claim 11 , wherein the fixed resistor is placed within the NEC integrated circuit. 
     
     
         13 . A short-distance contactless communication method, comprising:
 using a first receiver capable of operating under a proximity coupling device (PCD) mode and/or a proximity inductively coupled card (PICC) mode to couple to a signal receiving port of a chip;   tracking an envelope of a modulation signal on the signal receiving port of the chip and scaling the modulation signal on the signal receiving port of the chip proportionally during data communication phase, wherein a peak voltage level of the scaled modulation signal falls with a predetermined voltage range; and   receiving at the signal receiving port of the chip, by the first receiver, the scaled modulation signal, wherein the first receiver is located in the chip.   
     
     
         14 . The short-distance contactless communication method of  claim 13 , wherein the step of scaling the modulation signal on the signal receiving port of the chip proportionally during data communication phase comprises:
 presently scaling the peak voltage level of the modulation signal on the signal receiving port of the chip proportionally when the modulation signal appears on the signal receiving port of the chip.   
     
     
         15 . The short-distance contactless communication method of  claim 13 , wherein the step of scaling the modulation signal on the signal receiving port of the chip proportionally during data communication phase comprises:
 scaling the peak voltage level of the modulation signal on the signal receiving port of the chip proportionally to substantially equal a predetermined voltage level in the predetermined voltage range.   
     
     
         16 . The short-distance contactless communication method of  claim 13 , wherein the step of scaling the modulation signal on the signal receiving port of the chip proportionally during data communication phase comprises:
 scaling the peak voltage level of the modulation signal on the signal receiving port of the chip to fall within the predetermined voltage range during the PCD mode, and the modulation signal is an in-band blocker signal or a load modulation signal.   
     
     
         17 . The short-distance contactless communication method of  claim 13 , wherein the modulation signal is an ASK (Amplitude-shift keying) signal during data communication phase, and
 Wherein, during voltage regulation phase, the modulation signal is a continuous wave (CW) signal having an oscillating frequency substantially equal to 13.56 MHz and is adjusted to fall within the predetermined voltage range.   
     
     
         18 . The short-distance contactless communication method of  claim 13 , wherein the step of scaling the modulation signal on the signal receiving port of the chip proportionally during data communication phase comprises:
 scaling the peak voltage level of the modulation signal on the signal receiving port of the chip to fall within the predetermined voltage range during the PICC mode, and the modulation signal is a receiving ASK (Amplitude-shift keying) signal.   
     
     
         19 . The short-distance contactless communication method of  claim 13 , wherein the step of scaling the modulation signal on the signal receiving port of the chip proportionally during data communication phase comprises:
 using a programmable impedance component having a first terminal coupled to the signal receiving port and a second terminal coupled to a reference voltage for providing an impedance between the signal receiving port and the reference voltage according to an adjusting signal;   detecting an envelope of the modulation signal to generate a detecting signal; and   receiving the detecting signal and accordingly generating the adjusting signal to adjust the impedance of the programmable impedance component such that the peak voltage level of the modulation signal on the signal receiving port falls within the predetermined voltage range.   
     
     
         20 . The short-distance contactless communication method of  claim 19 , wherein the step of receiving the detecting signal and accordingly generating the adjusting signal to adjust the impedance of the programmable impedance component comprises:
 adjusting the impedance of the programmable impedance component such that the peak voltage level of the modulation signal on the signal receiving port substantially equals a predetermined voltage level in the predetermined voltage range.