Unlock instant, AI-driven research and patent intelligence for your innovation.

System for NFC card reader transmit modulation index self-calibration

A technology of transmission modulation and self-calibration, applied in transmitter monitoring, advanced technology, climate sustainability, etc., can solve problems such as poor control, time-consuming range, etc.

Active Publication Date: 2020-09-18
YICHIP MICROELECTRONICS (HANGZHOU) CO LTD
View PDF6 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In the current application, the parameters of the antenna and off-chip matching components are manually adjusted to avoid the variation of the modulation index beyond the range, which is time-consuming and the range is not easy to control

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • System for NFC card reader transmit modulation index self-calibration
  • System for NFC card reader transmit modulation index self-calibration
  • System for NFC card reader transmit modulation index self-calibration

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0013] refer to figure 2 , The NFC card reader modulation self-calibration system includes: a system for self-calibration of the NFC card reader emission modulation index, the NFC card reader is provided with an NFC card reader chip and an off-chip matching chip coupled with the NDC card reader chip The network element, the off-chip matching network element is coupled to the antenna, and the NFC card reader chip senses and receives the radio frequency signal of the electromagnetic coupling to the Type B card through the antenna, wherein the NFC card reader chip includes: used to transmit and modulate the carrier signal The gain amplifier PA, the gain amplifier is coupled with off-chip matching network components to transmit the NFC radio frequency AC carrier signal to the established electromagnetic coupling channel and passed to the TypeB card; the coupling amplifier coupled to the antenna is used to identify from the TypeB The radio frequency signal fed back by the type car...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

The self-calibration method for the NFC emission modulation index comprises the following steps: in a carrier measurement mode, S0 is closed, so that direct current under carrier mixing passes, an amplifier gain A is fixed and a PA gain is scanned, and a corresponding direct current value DC is obtained through a direct current estimation module; and in a normal working mode, S0 is disconnected, only a modulation signal passes through, and the amplifier gain A is adjusted according to the size of an actual received signal.

Description

technical field [0001] The present invention mainly scans the gain G of the power amplifier (PA) through the polling gap of the near-field communication (NFC) card reader, and simultaneously uses the digital receiver to measure the corresponding carrier amplitude to obtain the PA corresponding to the standard ASK modulation index. Gain, so that the ASK modulation index does not depend on the antenna design of such NFC systems, the matching network and the distance between the NFC card antenna and the NFC reader antenna must be kept constant. A method of self-calibration of the radio frequency transmission modulation index. Background technique [0002] NFC card readers usually use ASK modulation for Type B cards, and the modulation index will change with the distance between the Type B card and the current NFC card reader. This change is related to the specific antenna and NFC card reader chip. It is related to the design parameters of the off-chip matching components. In s...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
IPC IPC(8): H04B17/13
CPCH04B17/13Y02D30/70
Inventor 何济柔
Owner YICHIP MICROELECTRONICS (HANGZHOU) CO LTD