CN201319582Y

CN201319582Y - Radio frequency signal preamplifying circuit

Info

Publication number: CN201319582Y
Application number: CNU2008201804575U
Authority: CN
Inventors: 陈志明; 杜坦; 石万文; 江石根
Original assignee: SUZHOU HUAXIN MICRO-ELECTRONICS Co Ltd
Current assignee: SUZHOU HUAXIN MICRO-ELECTRONICS Co Ltd
Priority date: 2008-12-03
Filing date: 2008-12-03
Publication date: 2009-09-30
Anticipated expiration: 2018-12-03

Abstract

The utility model discloses a radio frequency signal preamplifying circuit. The amplifying circuit can be integrated into one IC with a decoder, and comprises a first MOS transistor (M1), a second MOS transistor (M2), a third MOS transistor (M3) and a fourth MOS transistor (M4); wherein the grid electrodes of the first MOS transistor (M1) and the second MOS transistor (M2) are mutually connected to form difference amplification to further amplify the input signal; the source electrodes and the grid electrodes of the third MOS transistor (M3) and the fourth MOS transistor (M4) are also respectively connected together, and the drain electrode and the grid electrode of the fourth MOS transistor (M4) are connected together to form a current mirror circuit; the input signal to be amplified and the amplified output signal are respectively connected on the source electrode and the drain electrode of the first transistor. The amplifying circuit has the advantages that the power consumption is low, the stability is good, and the signal receiving and sending distance can be enlarged.

Description

Pre-amplification circuit for radiofrequency signal

Technical field

The utility model relates to a kind of amplifying circuit, relates in particular to the pre-amplification circuit of the radiofrequency signal of utilizing integrated circuit (IC) design.

Background technology

Now, a large amount of less radio-frequency (RF) remote controls that use such as automobile safety system, garage control, digital remote control doorbell, remote-control toy and Industry Control or the like, are greatly improved production efficiency and quality of life in producing and living; Such remote control generally comprises emitter and receiving system two parts, and for the emitter part, one adopts low energy-consumption electronic device, improves the transmitting terminal emission effciency; And for receiving system, decode to reduce noise effect etc. after adopting multistage amplification, superregenrative reception technology, right RF in the market receives decode system mostly as shown in Figure 1, amplifies by being sent to the RF signal processing module behind the superregenerative module receiving demodulation, gives decoding IC at last.And the RF signal processing module adopts a large amount of discrete device (the empty frame of Fig. 1), and system complex is loaded down with trivial details, poor stability, and the production cycle is long, and cost is higher.Universal amplifier 358 is bipolar (Bipolar) technology, and its operating voltage is 5V, and operating current is big, causes system power dissipation big.Because the discreteness of discrete device characteristic, promptly its consistency of performance is bad, thereby causes receiving the decode system unstable properties, make different finished products be correctly decoded apart from the time far away when near.

Other has the amplifier that adds input signal on the employing metal-oxide-semiconductor grid and form, because the signal after the superregenerative demodulation is little of millivolt (mV) level, this needs the resistance capacitance of integrated majority, and integrated a large amount of resistance capacitance area occupied are very big in IC, and chip cost is just very high like this.

Summary of the invention

The purpose of this utility model will address the above problem exactly, by integrated RF amplifying circuit in decoding IC, reduces a large amount of peripheral discrete devices, simplifies application circuit, improves the stability of a system, reduces power consumption, reduces product cost.

For achieving the above object, the utility model is taked following technical scheme: a kind of pre-amplification circuit for radiofrequency signal, this amplifying circuit comprises first MOS transistor (M1), second MOS transistor (M2), the 3rd MOS transistor (M3) and the 4th MOS transistor (M4), wherein the grid of first MOS transistor (M1) and second MOS transistor (M2) interconnects, with form difference amplify to and input signal is amplified; The drain electrode of the 3rd MOS transistor (M3) and the 4th MOS transistor (M4) links to each other with the drain electrode of first MOS transistor (M1) and second MOS transistor (M2) respectively, and the source electrode of the 3rd MOS transistor (M3) and the 4th MOS transistor (M4) also is connected to grid, and the drain electrode of the 4th MOS transistor (M4) simultaneously also is connected to form current mirroring circuit with grid; Output signal (GG_OUT) after input signal to be amplified (IN) and the amplification is connected on the source electrode and drain electrode of first MOS transistor (M1).

Wherein, described amplifying circuit comprises that also plural number is connected to the resistance of described first MOS transistor and the second MOS transistor source terminal; This resistance that is connected first MOS transistor and the second MOS transistor source terminal equates.

The size and the performance parameter of described first MOS transistor and second MOS transistor are identical.

The performance parameter of described the 3rd MOS transistor and the 4th MOS transistor is identical.

Described amplifying circuit comprises that also a pair of described output signal carries out the comparator of shaping.

A described amplifying circuit and a decoder are integrated among the same IC.

With respect to prior art, the utlity model has following advantage:

1) integrated amplification module is minimum, does not increase original decoding IC area;

2) peripheral components is few, only needs a coupling capacitance, and system is succinct, and cost is low;

3) normal working voltage can be hanged down 2V, obviously reduces system power dissipation;

4) system stability, superior performance has increased the signal transmitting and receiving distance.

Description of drawings

Fig. 1 is that existing RF receives the decode system schematic diagram;

Fig. 2 is the utility model RF signal pre-amplification circuit structure chart;

Fig. 3 is the circuit structure diagram of amplifying circuit output after shaping among Fig. 2;

Fig. 4 is for using the module map of the utility model RF signal pre-amplification circuit.

Embodiment

The utility model pre-amplification circuit for radiofrequency signal is that RF (radio frequency) amplification module and decoder are integrated among the same IC, is coupled among the decoding IC that has processing RF signals by the signal of electric capacity after the superregenerative demodulation and decodes.Show as Fig. 2, this RF amplification module is for having the grid differential amplifier circuit altogether, it comprises MOS transistor M1, M2, M3, M4 (M1 and M2 are the PMOS transistor in the present embodiment, and M3 and M4 are nmos pass transistor), and is connected load resistance R1, R2, R3, the R4 of the source electrode of MOS transistor M1, M2.

Wherein MOS transistor M1, M2 are that the common grid input of difference is right, and promptly its grid interconnects, and model and performance parameter unanimity, plays signal and amplifies, and Vbias is transistor M1, and the operate as normal of M2 provides bias voltage; MOS transistor M3, M4 are active load, its source electrode is connected to current source I jointly, grid also interconnects, and the drain electrode of MOS transistor M4 is connected with grid, to form current mirroring circuit, during design, the size of MOS transistor M3, M4 and performance parameter are set in full accord, equate with the electric current that flows through MOS transistor M3 so that flow through the electric current of MOS transistor M4, and convert differential signal to single-ended signal output.

Four resistance R 1, R2, R3, R4 are connected on the source electrode of MOS transistor M1, M2 respectively symmetrically, be for good input characteristics being provided and improving gain amplifier as source end load, and resistance R 3 add that the value of R4 equals the value that R1 adds R2.The IN end links to each other through the source electrode of resistance R 1 with MOS transistor M1, and it is the input of small magnitude signal; The CG_OUT end links to each other with the drain electrode of MOS transistor M1 and the drain electrode of MOS transistor M3, is the output through amplifying signal.Amplify through cathode-input amplifier,, deliver to the back level and go shaping at the CG_OUT end output big amplitude waveform identical with the input signal phase place.

Comparator among Fig. 3 is mainly finished shaping feature, and the signal after the prime cathode-input amplifier amplifies obtains the high-low level signal of standard by comparator, for back stages of digital circuit provides accessible signal waveform.The reference voltage Vref of comparator is designed to and can adjusts according to the signal waveform of CG_OUT, the CG_OUT waveform is that input signal amplitude and the frequency with IN changes, so can at utmost reduce shaping process problem of dtmf distortion DTMF, realize the reception decoding of big distance.

Fig. 4 is the module map of the utility model RF signal pre-amplification circuit; As shown, RF signal pre-amplifying module and decoder module are integrated among the IC, optimize signal path when reducing peripheral components in a large number, reduce system power dissipation, improve systematic function and stability.Demodulate the frequency waveform of original signal after the superregenrative reception demodulation module receives the RF signal, the RF pre-amplification circuit that is coupled among the IC by capacitor C amplifies shaping, obtains standardized digital signal and gives the fixed code decoder.Because RF amplification module and digital decoding module process can be compatible, adopt lower-cost CMOS technology.And amplifying circuit of the present utility model is because of integrated a few little resistance resistance, and do not have electric capacity, so shared chip area is minimum, the chip after integrated can operate as normal more than 2V, really realize operating on low voltage, significantly reduce system power dissipation.

Technology contents of the present utility model and technical characterictic have disclosed as above; yet those of ordinary skill in the art still may be based on teaching of the present utility model and announcements and are done all replacement and modifications that does not deviate from the utility model spirit; therefore; the utility model protection range should be not limited to the content that embodiment discloses; and should comprise various do not deviate from replacement of the present utility model and modifications, and contained by the present patent application claim.

Claims

1. pre-amplification circuit for radiofrequency signal, it is characterized in that: this amplifying circuit comprises first MOS transistor (M1), MOS transistor (M2), the 3rd MOS transistor (M3) and the 4th MOS transistor (M4), wherein the grid of first MOS transistor (M1) and second MOS transistor (M2) interconnects, with form difference amplify to and input signal is amplified; The drain electrode of the 3rd MOS transistor (M3) and the 4th MOS transistor (M4) links to each other with the drain electrode of first MOS transistor (M1) and MOS transistor (M2) respectively, and the source electrode of the 3rd MOS transistor (M3) and the 4th MOS transistor (M4) also is connected to grid, and the drain electrode of the 4th MOS transistor (M4) simultaneously also is connected to form current mirroring circuit with grid; Output signal (GG_OUT) after input signal to be amplified (IN) and the amplification is connected on the source electrode and drain electrode of first MOS transistor (M1).

2. pre-amplification circuit for radiofrequency signal according to claim 1, it is characterized in that: described amplifying circuit comprises that also plural number is connected to the resistance of described first MOS transistor and the second MOS transistor source terminal.

3. as pre-amplification circuit for radiofrequency signal as described in the claim 2, it is characterized in that: the described resistance that is connected first MOS transistor and the second MOS transistor source terminal equates.

4. pre-amplification circuit for radiofrequency signal according to claim 1, it is characterized in that: the size and the performance parameter of described first MOS transistor and MOS transistor are identical.

5. pre-amplification circuit for radiofrequency signal according to claim 1, it is characterized in that: the performance parameter of described the 3rd MOS transistor and the 4th MOS transistor is identical.

6. pre-amplification circuit for radiofrequency signal according to claim 1 is characterized in that: described amplifying circuit comprises that also a pair of described output signal carries out the comparator of shaping.

7. pre-amplification circuit for radiofrequency signal according to claim 1, it is characterized in that: a described amplifying circuit and a decoder are integrated among the same IC.