CN204993318U - Near field communications received circuit - Google Patents
Near field communications received circuit Download PDFInfo
- Publication number
- CN204993318U CN204993318U CN201520539839.2U CN201520539839U CN204993318U CN 204993318 U CN204993318 U CN 204993318U CN 201520539839 U CN201520539839 U CN 201520539839U CN 204993318 U CN204993318 U CN 204993318U
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- circuit
- nfc
- amplifier
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- control
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- 238000004891 communication Methods 0.000 title claims description 8
- 238000007493 shaping process Methods 0.000 claims description 4
- 230000003321 amplification Effects 0.000 claims description 3
- 238000001514 detection method Methods 0.000 claims description 3
- 238000003199 nucleic acid amplification method Methods 0.000 claims description 3
- 230000008878 coupling Effects 0.000 abstract description 4
- 238000010168 coupling process Methods 0.000 abstract description 4
- 238000005859 coupling reaction Methods 0.000 abstract description 4
- 238000010586 diagram Methods 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 3
- 238000000034 method Methods 0.000 description 2
Classifications
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
- H04B1/06—Receivers
- H04B1/16—Circuits
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- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Circuits Of Receivers In General (AREA)
Abstract
The embodiment of the utility model discloses NFC receiving circuit, NFC receiving circuit includes: receive coupling incoming signal's coupler, confirm with the coupling after the corresponding control signal's of incoming signal's amplitude gain control circuit, control circuit's input with the output of coupler links to each other, the input is received incoming signal, according to control signal enlargies incoming signal to incoming signal's after enlargeing through output first amplifier, the control end of first amplifier with control circuit's output links to each other.
Description
Technical Field
The utility model relates to a near field communication (near field communication, NFC) signal processing technique especially relates to an NFC receiving circuit.
Background
NFC is a non-contact identification and interconnection technology that enables near field wireless communication between mobile devices, consumer electronics, desktop computers, and intelligent control tools. Currently, the NFC technology of 13.56MHz is widely applied to smart terminals.
Traditional NFC antenna occupation space is great, but along with intelligent terminal's function is more and more, intelligent terminal's structure is compacter and more, just also can be littleer and smaller for the space of NFC antenna distribution, consequently, the miniaturization of NFC antenna becomes in order to develop the trend.
However, when the NFC antenna is miniaturized, the NFC receiving circuit is not improved, and the miniaturization of the NFC antenna will result in a reduction in the receiving power of the NFC antenna and a reduction in the signal receiving capability; accordingly, the quality of the signal transmitted from the antenna to the NFC chip is poor. Therefore, the prior art fails to solve the problem of insufficient antenna reception power when NFC uses a small antenna.
SUMMERY OF THE UTILITY MODEL
In order to solve the above technical problem, an embodiment of the present invention is expected to provide an NFC receiving circuit, which can solve the problem that the antenna receiving power brought by NFC when using a small antenna is not enough.
The technical scheme of the utility model is realized like this:
in a first aspect, a near field communication, NFC, receiving circuit is provided, the NFC receiving circuit comprising:
a coupler that receives and couples an input signal;
a control circuit that determines a control signal corresponding to an amplitude gain of the coupled input signal; the input end of the control circuit is connected with the output end of the coupler;
the input end receives the input signal, amplifies the input signal according to the control signal, and outputs the amplified input signal through the output end; and the control end of the first amplifier is connected with the output end of the control circuit.
With reference to the first aspect, in a first implementable manner, the NFC receiving circuit further includes:
and the input end of the adjusting circuit is connected with the output end of the first amplifier.
With reference to the first aspect or the first implementable manner, in a second implementable manner, the NFC reception circuit further includes:
and the output end of the second amplifier is connected with the input end of the coupler.
With reference to the first aspect, in a third implementation manner, the control circuit is a control circuit that tracks and amplifies the coupled input signal to obtain a tracked and amplified signal, determines an envelope of the tracked and amplified signal, and determines a control signal corresponding to fluctuation of the envelope.
With reference to the first aspect, in a fourth implementable manner, the control circuit is a first low noise amplifier, and a response frequency of the control circuit is consistent with a reception frequency of the NFC reception circuit.
With reference to the fourth implementable manner, in a fifth implementable manner, the control circuit is an envelope tracking and amplifying ET envelope tracking circuit, and an output of the ET envelope tracking circuit is a control voltage.
With reference to the fifth implementable manner, in a sixth implementable manner, the first amplifier is a voltage controlled amplifier.
With reference to the first aspect, in a seventh implementable manner, the coupler is a radio frequency coupler.
With reference to the first implementable manner, in an eighth implementable manner, the adjusting circuit is a detection shaping circuit.
With reference to the second implementable manner, in a ninth implementable manner, the second amplifier is a Low Noise Amplifier (LNA).
The embodiment of the utility model provides a NFC receiving circuit of near field communication technology, which is provided with a coupler, a control circuit and a first amplifier; receiving and coupling an input signal through a coupler; determining, by a control circuit, a control signal corresponding to an amplitude gain of the coupled input signal; the input signal is then amplified using a first amplifier according to a control signal. Therefore, the input signal is coupled by the coupler and then is output by the control circuit to be amplified by the first amplifier according to the control signal, so that the purpose of increasing the input signal is achieved; furthermore, the control signal is determined according to the input signal after tracking amplification and coupling, that is, the control signal is changed according to the change of the amplitude gain of the input signal, and the first amplifier changes the amplification factor according to the change of the amplitude gain of the input signal, so that the signal-to-noise ratio of the NFC receiving circuit is improved, and the problem of insufficient antenna receiving power caused by using a small antenna in NFC is solved.
Drawings
Fig. 1 is a schematic structural diagram of an NFC receiving circuit provided in the present invention;
fig. 2 is a schematic structural diagram of another NFC receiving circuit provided in the present invention;
fig. 3 is a schematic structural diagram of another NFC receiving circuit provided in the present invention.
Detailed Description
The technical solution in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.
The utility model provides a NFC receiving circuit 10, as shown in fig. 1, this NFC receiving circuit 10 can include: a coupler 101, a control circuit 102, and a first amplifier 103; wherein,
the coupler 101 is used to receive and couple an input signal.
Preferably, coupler 101 is a radio frequency coupler.
The control circuit 102 is configured to determine a control signal corresponding to an amplitude gain of the coupled input signal.
Here, an input terminal of the control circuit 102 is connected to an output terminal of the coupler 101.
Specifically, the control circuit 102 may be configured to track and amplify the coupled input signal to obtain a track-amplified signal; determining an envelope tracking the amplified signal; determining a control signal corresponding to the fluctuation of the envelope of the tracking amplified signal; wherein the control signal may be an envelope signal.
Since the waveform of the envelope of the NFC received signal is a rectangular square wave, the phase distortion of the input signal amplified by the first amplifier has little influence on the final signal demodulation, but the selection principle of the first amplifier is as follows: 1. the control circuit 102 is a first low noise amplifier; 2. the response frequency of the control circuit 102 and the reception frequency of the NFC reception circuit are kept the same. Therefore, the NFC receiving circuit 10 can effectively amplify the NFC receiving signal, and the signal-to-noise ratio of the receiving system is improved. Therefore, preferably, the control circuit 102 is an Envelope Tracking (ET) envelope tracking circuit, and an output of the ET envelope tracking circuit, i.e., a control signal, is a control voltage.
The first amplifier 103 is configured to amplify the input signal according to a control signal.
Here, a control terminal of the first amplifier 103 is connected to an output terminal of the control circuit 102, an input terminal of the first amplifier 103 is configured to receive an input signal, and an output terminal of the first amplifier 103 is configured to output an amplified input signal. And after the amplified input signal is output to the first amplifier, the amplified input signal is input to the NFC chip.
Since the control circuit outputs a control voltage, the preferred first amplifier is a voltage controlled amplifier. Here, in this embodiment, the ET technique is used in conjunction with a voltage-controlled amplifier to track and amplify the coupled input signal to obtain an envelope, the difference between the maximum amplitude gain and the minimum gain of the envelope is large, and then the voltage value of the control voltage is adjusted according to the amplitude gain, thereby objectively improving the signal-to-noise ratio of the circuit. Therefore, the input signal is coupled through the coupler, the control signal is output through the control circuit, the first amplifier is controlled to amplify the input signal according to the control signal, and therefore the purpose of increasing the input signal is achieved.
Further, as shown in fig. 2, the NFC receiving circuit further includes: an adjusting circuit 104, an input of the adjusting circuit 104 is connected to an output of the first amplifier 103, the adjusting circuit 104 is used for detecting and/or shaping the amplified input signal. Preferably, the adjusting circuit 104 is a detector-shaper circuit.
Further, as shown in fig. 2, the NFC receiving circuit further includes: a second amplifier 100, an output terminal of the second amplifier 100 being connected to an input terminal of the coupler 101; the second amplifier 100 is used to receive and amplify the original signal to obtain the input signal of the coupler. Preferably, the second amplifier 100 is a Low Noise Amplifier (LNA).
Here, the original signal is an NFC radio frequency signal received by an NFC antenna; when the second amplifier 100 is not provided, the input signal is the NFC radio-frequency signal received by the NFC antenna, and when the second amplifier 100 is provided, the input signal is the NFC radio-frequency signal received by the NFC antenna amplified by the second amplifier 100.
The workflow of this embodiment includes: as shown in fig. 3, NFC receives an NFC radio frequency signal through an antenna, and the NFC radio frequency signal is first amplified by a front-end LNA 300; a part of the amplified NFC radio-frequency signal is coupled through the radio-frequency coupler 301, the coupled signal enters the ET envelope tracking circuit 302, the ET envelope tracking circuit 302 provides a fitted control voltage according to fluctuation of an envelope of the coupled signal, and a part of the amplified NFC radio-frequency signal enters the voltage-controlled amplifier 303; the voltage-controlled amplifier 303 controls to amplify the NFC radio-frequency signal again according to the control voltage provided by the ET envelope tracking circuit 302; the amplified NFC rf signal enters the detection shaping circuit 304, the overshoot and nonlinearity of the signal are detected and shaped, an output signal is output, and the output signal is finally input to the NFC chip.
The above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention.
Claims (10)
1. A near field communication, NFC, receive circuit, the NFC receive circuit comprising:
a coupler that receives and couples an input signal;
a control circuit that determines a control signal corresponding to an amplitude gain of the coupled input signal; the input end of the control circuit is connected with the output end of the coupler;
the input end receives the input signal, amplifies the input signal according to the control signal, and outputs the amplified input signal through the output end; and the control end of the first amplifier is connected with the output end of the control circuit.
2. The NFC receive circuit of claim 1, further comprising:
and the input end of the adjusting circuit is connected with the output end of the first amplifier.
3. The NFC receiving circuit according to claim 1 or 2, further comprising:
and the output end of the second amplifier is connected with the input end of the coupler.
4. The NFC receiver circuit of claim 1, wherein the control circuit is configured to track and amplify the coupled input signal to obtain a track-amplified signal, determine an envelope of the track-amplified signal, and determine a control signal corresponding to a fluctuation of the envelope.
5. The NFC receiving circuit according to claim 1, wherein the control circuit is a low noise amplifier, and a response frequency of the control circuit is kept coincident with a receiving frequency of the NFC receiving circuit.
6. The NFC receiving circuit of claim 5, wherein the control circuit is an envelope tracking amplification (ET) envelope tracking circuit, and wherein an output of the ET envelope tracking circuit is a control voltage.
7. The NFC receiving circuit of claim 6, wherein the first amplifier is a voltage controlled amplifier.
8. The NFC receive circuit of claim 1, wherein the coupler is a radio frequency coupler.
9. The NFC receive circuit of claim 2, wherein the adjustment circuit is a detection shaping circuit.
10. The NFC receive circuit of claim 3, wherein the second amplifier is a Low Noise Amplifier (LNA).
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201520539839.2U CN204993318U (en) | 2015-07-23 | 2015-07-23 | Near field communications received circuit |
| PCT/CN2015/090009 WO2017012188A1 (en) | 2015-07-23 | 2015-09-18 | Near field communication receive circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201520539839.2U CN204993318U (en) | 2015-07-23 | 2015-07-23 | Near field communications received circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN204993318U true CN204993318U (en) | 2016-01-20 |
Family
ID=55127637
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201520539839.2U Active CN204993318U (en) | 2015-07-23 | 2015-07-23 | Near field communications received circuit |
Country Status (2)
| Country | Link |
|---|---|
| CN (1) | CN204993318U (en) |
| WO (1) | WO2017012188A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2018171723A1 (en) * | 2017-03-24 | 2018-09-27 | 深圳市文鼎创数据科技有限公司 | Near field communication front-end hardware circuit, terminal, reader/writer, system and method |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7683851B2 (en) * | 2007-03-19 | 2010-03-23 | Broadcom Corporation | Method and system for using a single transformer for FM transmit and FM receive functions |
| KR101544859B1 (en) * | 2009-03-23 | 2015-08-17 | 삼성전자주식회사 | Auto gain controller and communication terminal having the same |
| KR101656083B1 (en) * | 2011-09-15 | 2016-09-09 | 한국전자통신연구원 | Apparatus and method for obtaining reception synchronization in wireless communication system |
| US9184798B2 (en) * | 2012-03-12 | 2015-11-10 | Broadcom Corporation | Near field communications (NFC) device having adjustable gain |
| CN110417440B (en) * | 2013-09-04 | 2021-09-07 | 联发科技（新加坡）私人有限公司 | Envelope extraction apparatus, signal decoding apparatus, short-range contactless communication apparatus, and related methods |
-
2015
- 2015-07-23 CN CN201520539839.2U patent/CN204993318U/en active Active
- 2015-09-18 WO PCT/CN2015/090009 patent/WO2017012188A1/en active Application Filing
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2018171723A1 (en) * | 2017-03-24 | 2018-09-27 | 深圳市文鼎创数据科技有限公司 | Near field communication front-end hardware circuit, terminal, reader/writer, system and method |
Also Published As
| Publication number | Publication date |
|---|---|
| WO2017012188A1 (en) | 2017-01-26 |
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