CN101964666A

CN101964666A - ETC (Electronic Temperature Controller) transceiver

Info

Publication number: CN101964666A
Application number: CN2010102944743A
Authority: CN
Inventors: 王树甫
Original assignee: Individual
Current assignee: Individual
Priority date: 2010-09-28
Filing date: 2010-09-28
Publication date: 2011-02-02

Abstract

The invention discloses an ETC (Electronic Temperature Controller) transceiver, comprising a low noise radio frequency front end LNA, a radio frequency signal amplitude detection circuit DET, a wakeup circuit WAKEUP, a receiving amplifier RX, a total integrated decimal closed loop phase-locked-loop PLL, a radio frequency amplifier PA, a crystal oscillating circuit CRYSTAL and a power supply management circuit LDO. When in receiving, the low noise radio frequency front end amplifies a signal, and the radio frequency signal amplitude detection circuit and the receiving amplifier receive a wide band of a radio frequency signal; when in emitting, the total integrated decimal closed loop phase-locked-loop generates a carrier wave signal, the carrier wave signal subjected to amplitude modulation of emit data is transmitted by the radio frequency amplifier; and when in wakeup, the radio frequency signal amplitude detection circuit detects a wakeup signal, and the wakeup circuit identifies the wakeup signal and sends a wakeup indication signal. In the invention, high integration of the ETC transceiver is realized; and the ETC transceiver is suitably applied to transceiving and wakeup functions of Chinese ETC systems in 5.8GHz radio frequency.

Description

The ETC transceiver

Affiliated technical field

The present invention relates to Dedicated Short Range Communications, (DSRC) technical field in the intelligent transportation system, the particularly Chinese ETC 5.8GHz of system radio-frequency receiving-transmitting application-specific integrated circuit (ASIC) field.

Background technology

The popularization of passing through a surname energetically of the formal issue on March 17th, 2007 and traffic department along with the standard GB/T20851 " electronic charging Dedicated Short Range Communications, " of Chinese highway electric toll collection applications.The condition of China Large scale construction ETC Fare Collection System possesses, and China ETC has entered and known clearly extensive the implementation phase.

In the ETC system, adopt Dedicated Short Range Communications, standard agreement (DSRC) to carry out half-duplex operation between OBU and the RSU, the present domestic ETC system frequency range of using is the 5.8GHz system, China's standard definition physical layer and data link layer, have independent intellectual property right fully.Because GB is different with the standard of other countries, so also there is not a very high integrated chip of integrated level that meets GB on the market.

Summary of the invention

The object of the present invention is to provide a kind of ETC transceiver, reception, emission, wake-up circuit and the electric power management circuit chip of radio frequency integrated, realize advantages such as high integration, low-power consumption.

The technical scheme of a kind of ETC transceiver of the present invention is: comprise low noise radio-frequency front-end LNA, radio-frequency signal amplitude detection circuit DET, wake-up circuit WAKEUP, reception amplifier RX, fully integrated decimal closed loop phase-locked loop pll, radio frequency amplifier PA, crystal oscillator oscillating circuit CRYSTAL and electric power management circuit LDO, and be integrated in the same chip; When receiving, described low noise radio-frequency front-end LNA amplifies signal, and described radio-frequency signal amplitude detection circuit DET realizes the broadband reception of radiofrequency signal; In emission at present, described fully integrated decimal closed loop phase-locked loop pll produces carrier signal, through the amplitude modulation(PAM) of emission data, is launched by described radio frequency amplifier PA; When waking up, described radio-frequency signal amplitude detection circuit DET realizes the detection of wake-up signal, and described wake-up circuit WAKEUP discerns wake-up signal, and sends and wake index signal up.

The present invention has following advantage:

(1) described fully integrated decimal closed loop phase-locked loop is integrated loop filter;

(2) realize that based on described radio-frequency signal amplitude detection circuit rf broadband receives;

(3) required device is few, and the impedance matching of detection antenna is simple, is easy to a large amount of production and debugging;

(4) simultaneously integrated electric power management circuit makes this chip can be operated in the big change in voltage scope.

Description of drawings

The structural representation of Fig. 1 ETC transceiver

The circuit diagram of Fig. 2 CMOS difference radio-frequency signal amplitude detection circuit

The structural representation of the 5.8GHz decimal closed loop phase-locked loop pll that Fig. 3 is fully integrated

Embodiment

The present invention is further detailed explanation below in conjunction with drawings and Examples:

This exemplary application is in the Chinese ETC 5.8GHz of system radio-frequency receiving-transmitting application-specific integrated circuit (ASIC) field.According to the requirement of GB Dedicated Short Range Communications, physical layer GBT20851.1-2007, its operating frequency 5.8GHz.

As shown in Figure 1, ETC transceiver of the present invention comprises low noise radio-frequency front-end LNA, radio-frequency signal amplitude detection circuit DET, wake-up circuit WAKEUP, reception amplifier RX, fully integrated 5.8GHz decimal closed loop phase-locked loop pll, radio frequency amplifier PA, crystal oscillator oscillating circuit CRYSTAL and electric power management circuit LDO, and is integrated in the same chip.

Under receiving mode, described low noise radio-frequency front-end amplifies LNA with signal, the described radio-frequency signal amplitude detection circuit DET that realizes based on CMOS technology further finishes the detection to 5.8GHz weak radio-frequency signal amplitude in the ETC system, described reception amplifier RX is with rectified signal amplification, filtering, thus output broadband reception data.This rf broadband receives the testing circuit that the framework design key is the radiofrequency signal amplitude that CMOS technology realizes.The circuit of CMOS difference radio-frequency signal amplitude detection circuit as shown in Figure 2.Owing to adopt a plurality of MOS transistor series connection to make the amplitude detection of each MOS transistor export the series connection addition, thereby obtain n detection gain doubly.Each MOS transistor of input impedance import to(for) radio frequency is in parallel, and whole input impedance value has reduced n doubly, and the coupling that is beneficial to the radio frequency input realizes.It is opposite that radiofrequency signal input anode Rfin+ links to each other in proper order with radiofrequency signal input negative terminal Rfin-.The input impedance that has guaranteed radiofrequency signal input anode Rfin+ and radiofrequency signal input negative terminal Rfin-like this is identical, and the working method of entire circuit is a fully differential.

The ETC system of domestic use provides the 5.8GHz wake-up signal of 14kHz square-wave frequency modulation.When waking up, described radio-frequency signal amplitude detection circuit DET realizes the detection of wake-up signal, and described wake-up circuit WAKEUP realizes this 14kHz square wave wake-up signal is discerned, and discerns correctly and sends and wake index signal up.Avoid other interference signal false wake-ups ETC transceiver like this, cause unnecessary energy consumption.

In emission at present, described fully integrated 5.8GHz decimal closed loop phase-locked loop pll produces carrier signal, and the carrier signal mixing with 5.8GHz after the filtering of emission data process obtains the 5.8Ghz modulation signal, and PA launches by radio frequency amplifier; Described fully integrated 5.8GHz decimal closed loop phase-locked loop as shown in Figure 3, the VCO of 5.8GHz makes tranmitting frequency consistent with reference frequency by the loop that frequency divider, phase discriminator and charge pump constitute, and does not change with temperature and process deviation.And integrated circuit such as loop filter do not need external device.SDM decimal closed loop phase-locked loop makes system can support many clocks clock frequency.

In order to realize still can normally using under the broad supply voltage, this chip internal is integrated electric power management circuit LDO makes this chip can be operated in the voltage range of 2.2V～3.6V.

The above is specific embodiment that the present invention is directed to the 5.8GHz of ETC system radio-frequency receiving-transmitting field, can be applicable to other radio-frequency systems simultaneously and uses, and for example RFID uses etc.

Claims

1. ETC transceiver, comprise low noise radio-frequency front-end LNA, radio-frequency signal amplitude detection circuit DET, wake-up circuit WAKEUP, reception amplifier RX, fully integrated decimal closed loop phase-locked loop pll, radio frequency amplifier PA, crystal oscillator oscillating circuit CRYSTAL and electric power management circuit LDO, it is characterized in that: the reception of radio frequency, emission, wake-up circuit and electric power management circuit chip integrate;

When receiving, described low noise radio-frequency front-end amplifies LNA with signal, and described radio-frequency signal amplitude detection circuit DET realizes the broadband reception of radiofrequency signal;

In emission at present, described fully integrated decimal closed loop phase-locked loop pll produces carrier signal, through the amplitude modulation(PAM) of emission data, is launched by described radio frequency amplifier PA;

When waking up, described radio-frequency signal amplitude detection circuit DET realizes the detection of described wake-up signal, and described wake-up circuit WAKEUP discerns wake-up signal, and sends and wake index signal up.

2. according to the described a kind of ETC transceiver of claim 1, it is characterized in that: described fully integrated decimal closed loop phase-locked loop pll is integrated loop filter.

3. according to the described a kind of ETC transceiver of claim 1, it is characterized in that: realize that based on described radio-frequency signal amplitude detection circuit DET rf broadband receives.

4. according to the described a kind of ETC transceiver of claim 1, it is characterized in that: described radio-frequency signal amplitude detection circuit DET realizes the detection of wake-up signal, and described wake-up circuit WAKEUP discerns the testing result of wake-up signal, and sends and wake index signal up.

5. according to claim 3 or the described a kind of ETC transceiver of claim 4, it is characterized in that: described radio-frequency signal amplitude detection circuit DET realizes based on CMOS technology.