CN102868369B - Radio frequency automatic gain control amplifier - Google Patents
Radio frequency automatic gain control amplifier Download PDFInfo
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- CN102868369B CN102868369B CN201110186734.XA CN201110186734A CN102868369B CN 102868369 B CN102868369 B CN 102868369B CN 201110186734 A CN201110186734 A CN 201110186734A CN 102868369 B CN102868369 B CN 102868369B
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Abstract
The invention discloses a radio frequency automatic gain control amplifier. The radio frequency automatic gain control amplifier comprises a radio frequency receiving unit, a radio frequency amplifier control unit and an intermediate frequency amplifier, wherein the radio frequency receiving unit is composed of an adjustable low noise amplifier (LNA), a programmable gain amplifier (PGA), a down-conversion frequency mixer and a low-pass filter; the radio frequency amplifier control unit comprises a signal strength detector, a DAC (digital-to-analog converter), a comparator and a decoder; the signal strength detector is used for detecting the strength of an intermediate frequency signal; a comparator circuit is used for comparing an output signal of the signal strength detector with a fixed comparing level output from the DAC so as to output a comparison result; the decoder is used for inputting the comparison result into a gain control digital module and outputting a digital control signal so as to carry out the feedback control to the signal at the front end of the radio frequency, so that the gains of the LNA and the PGA are controlled, the signal to noise ratio of a receiving system is increased, and the requirements on dynamic ranges and high linearity of an input signal are met. The automatic gain control amplifier can be used in various radio frequency receiving chips flexibly, and particularly is applicable to radio frequency front-end circuit which has a wider input range of a radio frequency signal.
Description
Technical field
The invention belongs to technology for radio frequency field, relate to a kind of radio frequency automatic growth control regulating circuit pattern, particularly relate to radio frequency automatic gain control amplifier, it adopts and is different from traditional gain-adjusted pattern, and it is applicable to the radio-frequency transmitter receiving great dynamic range signal.
Background technology
In recent years along with the continuous appearance of areas of information technology new technology and the continuous progress of technique, the input range of various receiver system is compared with all great changes have taken place originally, when different radio frequency signal works simultaneously simultaneously, interference between signal is also more and more serious, for weak input, the application scenario of large interference needs to receive function provides large input range and dynamic range.
As everyone knows, when different radio frequency signal works simultaneously, interference signal from other system is inevitable, and the radio-frequency (RF) front-end circuit of existing traditional receiver system is generally fixed gain pattern, for this situation having large exogenous disturbances, easy saturated radiofrequency signal front end, and chip internal is all adopt automatic gain control circuit at intermediate-frequency section in order to avoid disturbing, this circuit can not meet the requirement of large dynamic range, especially strong jamming weak signal input environment when multisystem works can not be adapted to, limitation in this gain amplifier structure and functionally, become the significant deficiency limiting its application.
The formation of traditional controllable gain amplifier comprises control circuit, amplifier main circuit, testing circuit and reference input circuit.Due in the prior art, normally in intermediate frequency ride gain, like this when radiofrequency signal input is excessive, owing to first occurring that at radio-frequency head circuit is due to saturated and affect signal to noise ratio, when after signal after filtering device filtering, the distortion reduction of signal, at this moment signal amplitude is controlled to claimed range again by intermediate frequency amplifier, this control mode completes on the basis of signal distortion, so the Signal-to-Noise of reality reduces, can not meet design requirement.For conventional art, it is be that the change intensity of signal is smaller that this technology at intermediate frequency end FEEDBACK CONTROL intermediate frequency amplifier is generally applied, and the condition that the intensity of another signal is little is especially got off and to be realized.
There is shortcomings in prior art controllable gain amplifier: the first, and traditional control mode adopts the scheme controlling intermediate frequency variable gain amplifier can only be suitable for the less situation of input signal dynamic range, has been not suitable for the application of great dynamic range initial conditions.The second, traditional design, does not consider that rf gain can regulate, and practical problem is exactly when input signal is very large, easily that radio frequency part is saturated, and light relies on intermediate frequency to control to meet existing designing requirement.3rd, based on the noise factor reducing system, traditional control method mainly requires that setting front-end gain is fixed size, but the system of reality can be larger due to input, require so not high to the noise factor of system front end, when input signal is larger, require very high to system linearity degree, but fixed RF front end can not meet high linearity requirement, fixed gain can make the signal-to-noise ratio degradation of radio-frequency transmitter system on the contrary, final influential system performance.Traditional structure exists can not process the problem causing radio frequency amplifier saturated because input signal is excessive, and hardware resource can not be utilized to greatest extent, just signal is processed at radio-frequency front-end, too small signal just amplifies, and front end provides low noise simultaneously, and excessive signal just reduces, improve system linearity degree simultaneously, which reduce circuit overhead and power consumption, improve the performance of system, and the sensitivity of radio-frequency transmitter.
If there is a kind of radio frequency automatic gain control amplifier can change rf gain according to input size flexibly, the flexibility of whole radio-frequency front-end is not only made greatly to improve, and the ever-increasing market demand of better adaptation areas of information technology new technology.
Summary of the invention
The object of the invention is the above problem formed for solving the traditional radio-frequency receiver front-end of prior art, there is provided one can radio frequency automatic gain control amplifier, can be used for high dynamic radio-frequency transmitter and other need processing signals range large receiver in.It, except the function of variable gain amplifier possessing traditional receivers, also has the function of the low noise amplifier of radio frequency variable gain amplifier and adjustable gain, better can reduce hardware and system power expense, improves system signal noise ratio, and optimization system designs.As shown in Figure 1, the variable gain amplifier 101 that simulation AGC is made up of the cascade of some stage gain amplifying stages, peak detector 102, logarithmic amplifier 103, low pass filter 104 and correlator 105 form the control circuit theory diagram of traditional simulation AGC.The peak value that peak detector 102 outputs signal for detecting gain amplifier 101, send logarithmic amplifier 103 that signal is made logarithmic amplification, and peak signal after correlator 105 amplifies 103 and the reference voltage V of input
refcompare, export control signal and entered low pass filter 104 filtering, control signal is added to variable gain amplifier 101, the gain of ride gain amplifier 101.In whole radio-frequency receiving system, AGC is between complex intermediate frequency filter and ADC, it is according to the intermediate-freuqncy signal intensity received, carry out the amplification of different gains rank, make the intensity stabilization of output signal on certain level, thus give follow-up adc circuit relatively-stationary input voltage, ADC can be allowed like this to reach good performance and larger signal to noise ratio with lower resolution.
Traditional digital PGA control mode theory diagram as shown in Figure 2, the PGA (programmable gain amplifier) 21 of radio frequency front end chip is by the VGA (variable gain amplifier) 201 of multi-stage cascade, analog to digital converter 202 and digital to analog converter 203 are formed, digital baseband chip 22 is made up of digital comparator 204, DSP digital signal processing module 205 and accumulator 206.The amplifying signal of PGA exports and gives digital baseband block, and the output feedback signal of digital baseband block through the gain amplifier of digital to analog converter 203 control VGA, thus provides the amplification quantity of PGA.
Abandoning tradition structure can not be processed the problem causing radio frequency amplifier saturated because input signal is excessive by the present invention, a kind of radio frequency automatic gain control amplifier is proposed, utilizing on the basis of hardware resource to greatest extent, just signal is processed at radio-frequency front-end, too small signal just amplifies, front end provides low noise simultaneously, excessive signal just reduces, and improve system linearity degree, reduce circuit overhead and power consumption, improve the performance of system, and the sensitivity of radio-frequency transmitter, equipment power dissipation and volume can also be reduced, cost-saving.A kind of radio frequency automatic gain control amplifier of the present invention, is applicable to the radio frequency chip of many middle application, is particularly suitable for the application of Larger Dynamic input range signal.
Above-mentioned purpose of the present invention is realized by technical scheme below:
Radio frequency automatic gain control amplifier, it is that radio frequency automatic gain control amplifier is called for short radio frequency AGC amplifier and comprises rf receiver unit and radio frequency amplification control unit and intermediate frequency amplifier; Wherein
Described rf receiver unit by a gain-adjustable low-noise amplifier LNA, a variable gain amplifier PGA, a down-conversion mixer and low pass filter are formed; The input of gain-adjustable low-noise amplifier circuit connects radio-frequency input signals RF
iNPUTthe output of gain-adjustable low-noise amplifier connects the input of variable gain amplifier, the output of variable gain amplifier connects the input of frequency mixer, the output of frequency mixer connects the input of low pass filter, and the output of low pass filter connects the input of radio frequency amplification control unit input and next stage digital base band processor chip; Gain-adjustable low-noise amplifier LNA is connected the control signal output of radio frequency amplification control unit with the control end of variable gain amplifier PGA;
Described radio frequency amplification control unit is AGC control module, its input connects the output of the low pass filter of rf receiver unit, its two output correspondences connect the control end of gain-adjustable low-noise amplifier LNA and the control end of variable gain amplifier PGA, for realizing the control of radio frequency receiving element receiving gain;
The input of described intermediate frequency amplifier connects the output of the low pass filter of rf receiver unit, and its output connects next stage digital base band processor chip, amplifies for the intermediate-freuqncy signal exported low pass filter;
Described rf receiver unit and radio frequency amplification control unit and intermediate frequency amplifier are difference channel structure.
Described radio frequency automatic gain control amplifier, it is that the circuit composition of described radio frequency amplification control unit comprises signal strength detector RSSI, digital to analog converter DAC, comparator and demodulator Decoder; Wherein
Described signal strength detector RSSI is signal strength indicator circuit, be used for detect and instruction intermediate-freuqncy signal intensity;
Described digital to analog converter DAC, is converted to fixing analog signal voltage for Reference Signal;
Described comparator is two input terminal comparators, makes comparisons for fixed signal voltage signal strength detector output voltage and DAC exported, and exports a comparative result;
Described demodulator Decoder is digital demodulating circuit, and the digital signal for being inputted by comparator carries out processing the control signal that rear decoding exports the concrete gain size of ride gain adjustable low-noise amplifier LNA and variable gain amplifier PGA;
The input of signal strength detector RSSI connects the output of low pass filter, its output connects the signal input part of comparator, the output of digital to analog converter DAC connects the fixed reference potential input of comparator, the input of demodulator Decoder connects the output of comparator, and two output correspondences of demodulator Decoder connect the control end of LNA and PGA.
Described radio frequency automatic gain control amplifier, it is that described gain-adjustable low-noise amplifier is by inputting amplifying stage, load circuit, noise decrease inductance and low noise bypass structure composition; Low noise bypass structure comprises the bypass resistance R5 and R6 by-pass switch pipe that two tunnels are connected in series: R5 and M3, R6 and M4, the two port of the bypass resistance that two tunnels are connected in series and by-pass switch pipe should be attempted by Two-pass DINSAR input and difference output end: V
iNn and V
iNp, V
oUTn and V
oUTbetween P, the control end of by-pass switch pipe M3 with M4 is connected bypass control signal Vctrl1; Low noise bypass structure also comprises a bias voltage short switch pipe M5, and bias voltage short switch pipe M5 is attempted by the input pipe M1 of main amplifying stage and between the biased electrical pressure side Bias1 of M2 grid and ground, the control end of short switch pipe M5 connects bypass control signal Vctrl1; By-pass switch pipe and short switch pipe are controlled by bypass control signal simultaneously, control to access bypass resistance R5, a R6 by by-pass switch pipe between main amplifying stage Two-pass DINSAR input and difference output end, control main amplifying stage input pipe gate bias voltage directly by short switch pipe ground connection simultaneously, main amplifying stage input pipe M1 and M2 is turned off, exporting through bypass structure with zero gain and low noise at main amplifying stage for controlling large input signal, realizing one-level low noise amplifier and zero gain or fixed gain G are provided
lthe controlled coarse adjustment of two kinds of yield values is selected: G
lvalue is several times as much as the gain step value of variable gain amplifier PGA.
Described radio frequency automatic gain control amplifier, it is that described variable gain amplifier comprises several variable gain amplifying stage circuit; Each variable gain amplifying stage has gain control end, and the gain control end of each variable gain amplifying stage connects the same control signal output of radio frequency amplification control unit, and this control signal is digital controlled signal;
Several variable gain amplifying stage circuit are differential series syndeton, two-way radio-frequency differential input signal connects two differential input ends of first order variable gain amplifying stage circuit, and two difference output ends of final stage variable gain amplifying stage circuit connect radio frequency amplification control unit input and digital baseband chip differential input end; Each variable gain amplifying stage is the gain step value G of identical current gain value and variable gain amplifier
s, the maxgain value of variable gain amplifier is mG
s, m be greater than 2 positive integer.
Described radio frequency automatic gain control amplifier, it is that described signal strength detector is signal strength detection sample circuit, and it is made up of jointly amplitude detection circuit and comparator circuit and DAC-circuit; The intermediate-freuqncy signal IFInput of input range testing circuit connects the input of amplitude detection circuit, the output of amplitude detection circuit connects the comparison signal input of comparator, the output of two reference voltages VL, VH of DAC connects two reference signal inputs of comparator, and the output of comparator forms signal strength detection quantized value.
Form signal strength detection quantized value according to the output of comparator and can divide into three intervals: it was community that quantized value is less than setting reference voltage VL, it is stable region that quantized value is between setting reference voltage VL and VH, and it is excessive district that quantized value is greater than setting reference voltage VH.When quantized value was in community, the gain of the gain and variable gain amplifier that control digital module ride gain adjustable low-noise amplifier by gain increased; When quantized value is in excessive district, the gain of the gain and variable gain amplifier that control digital module ride gain adjustable low-noise amplifier by gain reduces; When quantized value is in the stable region between reference voltage VL and VH, assert that the amplitude of output signal meets the demands, the gain being controlled the gain of digital module ride gain adjustable low-noise amplifier and variable gain amplifier by gain is constant.
Described radio frequency automatic gain control amplifier, it is that described amplitude detection circuit is made up of the amplitude limiting amplifier circuit of amplitude detection unit, multi-stage cascade and voltage adder circuit, every grade of amplitude limiting amplifier circuit exports the corresponding detection signal end connecting the amplitude detection unit detected, the output of amplitude detection unit connects voltage adder circuit, and the output of voltage adder circuit is the output of amplitude detection circuit; Amplitude detection unit for detecting the output size of every grade of limited amplitude amplifying circuit, then is added by voltage adder circuit, obtains the voltage signal that can react amplitude output signal size.
The output of every grade of fixed gain amplitude limiting amplifier circuit of amplitude detection circuit all connects amplitude detection circuit, input signal is amplified to saturation distortion step by step through every grade of fixed gain amplitude limiting amplifier circuit, that grade of fixed gain width amplifying circuit causing outputing signal distortion is detected by amplitude detection unit, corresponding amplitude detection voltage is provided at the cascade number voltage accumulation of amplifier chain according to it, for the signal of different input range, amplitude detection circuit exports different amplitude detection voltage.
Described radio frequency automatic gain control amplifier, it is that described comparator circuit is 2bit digital comparator, the output port of input connection signal intensity detector, the voltage compare different from two height by the output voltage of signal strength signal intensity, obtain the digital output signal of 2bit, adopt the size of the result characterization signal intensity output voltage compared, represent that signal strength signal intensity is greater than high voltage VH when comparator exports 11, when the output 10 of comparator represents that signal strength signal intensity meets the demands between VL and VH, when the output of comparator is that the satisfied setting requirement of 00 expression signal strength signal intensity is less than VL.
Described radio frequency automatic gain control amplifier, it is that described gain controls digital module is feedback control loop, by the gain size of gain-variable unit before the output numeric results FEEDBACK CONTROL of comparator and the height change in gain of gain-adjustable low-noise amplifier.
First input signal can amplify by amplifier amplifying circuit through gain-adjustable low-noise amplifier and gain, intermediate frequency is down-converted to again through frequency mixer, device filtering after filtering, the size of signal strength signal intensity is detected again by intensity detection circuit, this signal is compared with reference level VH and VL, finally controls the gain size of digital module feedback control gain adjustable low-noise amplifier and variable gain amplifier again via gain.
Described radio frequency automatic gain control amplifier, it is that described low pass filter is fourth order low-pass filter construction structure, be made up of resistive degeneration and electric capacity and amplifier unit, its input receives the output signal from frequency mixer, the radio-frequency component in filtered signal.Ensure that intermediate-freuqncy signal can not be flooded by radiofrequency signal, avoid intermediate-frequency gain amplifying circuit to enter because of excessive radiofrequency signal the saturation condition cannot amplifying intermediate-freuqncy signal.
Described radio frequency automatic gain control amplifier, wherein be characterised in that: described gain controls the control signal end connection gain-adjustable low-noise amplifier of digital module and the gain control end of variable gain amplifier, the gain of control signal to gain-adjustable low-noise amplifier and variable gain amplifier that gain controls digital module output carries out control in order, the current gain value G of gain-adjustable low-noise amplifier
lwith variable gain amplifier gain step value G
sfor indoor design fixed value, G
l=nG
s, n be greater than 2 positive integer.
Regulating gain to increase process is the orderly control procedure that gain controls that digital module regulates gain-adjustable low-noise amplifier and variable gain amplifier gain.
When needs reduce gain, first the gain stepping controlling variable gain amplifier circuit reduces, if when the circuit gain of variable gain amplifier is reduced to minimum, then ride gain adjustable low-noise amplifier reduces gain, the gain stepping controlling variable gain amplifier again reduces, until the amplitude of output signal meets the demands, the gain that the gain stepping that gain controls digital module ride gain adjustable low noise increases the gain of acoustic amplifier and variable gain amplifier is constant.When needs increase gain, first the gain stepping controlling variable gain amplifier circuit increases, if the circuit gain of variable gain amplifier has increased to time maximum, then ride gain adjustable low-noise amplifier increases gain, the gain simultaneously controlling variable gain amplifier subtract arrive most little, the gain stepping controlling variable gain amplifier again reduces, until the amplitude of output signal meets the demands, the gain that the gain stepping that gain controls digital module ride gain adjustable low noise increases the gain of acoustic amplifier and variable gain amplifier is constant.
Substantial effect of the present invention:
1, the present invention just FEEDBACK CONTROL process is done to signal at radio-frequency front-end can be corresponding fast to input large-signal, overcome that prior art intermediate frequency end FEEDBACK CONTROL intermediate frequency amplifier exists be suitable for that input signal dynamic range is less, input signal is large time signal to noise ratio reduces, fixed RF front end can not meet high linearity and require to cause radio frequency amplifier saturated and can not utilize the defect of hardware resource to greatest extent.
2, radio-frequency front-end of the present invention is according to the size of input signal, change the focus of radio-frequency front-end leading indicator flexibly, application different system can regulate automatically according to the requirement of different system: the corresponding tuning linearity of large-signal, small-signal pays close attention to noise factor, realize optimization system design, improve system signal noise ratio.
3, the radio frequency automatic control circuit of the present invention's employing, does not need other additional element, does not need baseband feedback to control yet, and improves stability and the reaction speed of receiving system.
4, radio frequency automatic gain control amplifier of the present invention, is suitable for the receiver needing the work of great dynamic range initial conditions.
Accompanying drawing explanation
Fig. 1 is traditional radio frequency analog AGC control mode schematic block circuit diagram.In figure: 101 is variable gain amplifier, 102 is peak detector, and 103 is a logarithmic amplifier, and 104 is low pass filter, and 105 is correlator, V
reffor the reference voltage of input.
Fig. 2 is traditional radio-frequency (RF) digital PGA control circuit theory diagram.
In figure: 21 is radio-frequency front-end PGA, 202 is digital baseband chip, and 201 is the variable gain amplifier VGA of multi-stage cascade, 202 is analog-digital converter ADC, and 203 is digital to analog converter DAC, and 204 for being digital comparator, 205 is digital signal processing module, and 206 is accumulator.
Fig. 3 is that the circuit of the radio frequency automatic gain control amplifier of the embodiment of the present invention forms block diagram;
In Fig. 3: 31 is gain-adjustable low-noise amplifier, 32 is variable gain amplifier, and 33 is down-conversion mixer MIX, 34 is low pass filter LPF, and 35 is AGC control module, and wherein 301 is demodulator, 302 is digital to analog converter DAC, and 303 is comparator, and 304 is intensity detection circuit RSSI.The input of low noise amplifier 31 connects radio frequency input, and 34 low pass filters provide IF output signal.
Fig. 4 is that the digital television radio-frequency front-end chip of one embodiment of the present of invention forms block diagram; In Fig. 4: 41 is rf gain adjustable low-noise amplifier, 42 is radio frequency variable gain amplifier, and 43 is RF AGC control module, 44 and 45 is down-conversion mixer MIX, 46 and 47 is low pass filter LPF, and 48 and 49 is IF AGC control amplifier BB-AGC, V
1NNand V
1NPfor the input of the I of frequency gain-adjustable low-noise amplifier 41, Q two-way quadrature radio-frequency signals, V
oUTNand V
oUTPbe the I of 51 and 52 IF AGC control amplifiers, the orthogonal intermediate-freuqncy signal of Q two-way exports.
Fig. 5 is the circuit structure block diagram of the gain-adjustable low-noise amplifier of embodiment of the present invention radio frequency automatic gain control amplifier;
In Fig. 5: M1 and M2 is differential input stage, C1 and C2 is the electric capacity of isolated DC, L1 and L2 is load inductance, R1 and R2 provides bias voltage for biasing resistor, R3 and R4 is load resistance, and R5, R6 are bypass resistance, M3, M4 is by-pass switch pipe, and L3 is noise decrease inductance, and M5 is short switch pipe, V
iNn and V
iNp is differential input end, V
oUTn and V
oUTp is difference output end, and Bias1 is bias voltage input, and Vctrl1 is bypass control signal.
Fig. 6 a is the circuit structure block diagram of the signal strength detector of the embodiment of the present invention;
In Fig. 6 a: 61 is amplitude detection circuit, 62 is comparator, and 63 is DAC, VH and VL is the comparative voltage that subregion is arranged.
Fig. 6 b is input voltage in the embodiment of the present invention and the relation schematic diagram between the output voltage detected by intensity detection circuit;
In Fig. 6 b: the radio-frequency input signals Vin of gain-adjustable low-noise amplifier 41 in abscissa Fig. 4, ordinate represents the output signal Vout of low pass filter 46 in Fig. 4,
Fig. 6 c is the amplitude detection circuit in the embodiment of the present invention in signal strength detector
In Fig. 6 c: 61 is limiting amplifier, 602 ~ 605 be amplitude limit amplifying stage 1 ~ limited range enlargement level 4,62 is amplitude detection unit, is voltage adder circuit by 606 ~ 610 amplitude detection level 1 ~ amplitude detection levels 4,63.
Embodiment
Below by embodiment also by reference to the accompanying drawings, technical scheme of the present invention is further described in detail.
First embodiment
The circuit that Fig. 3 gives the radio frequency automatic gain control amplifier of the embodiment of the present invention forms block diagram.Composition graphs 3 illustrates automatic growth control pattern implementation procedure in the present invention.Radio-frequency input signals RFinput input gain adjustable low-noise amplifier 31, through the amplification of gain-adjustable low-noise amplifier 31, be input to radio frequency variable gain amplifier 32, the amplifying signal that variable gain amplifier 32 exports is the radiofrequency signal comprising intermediate-freuqncy signal at down-conversion mixer 33 and local oscillation signal frequency conversion, this radiofrequency signal, by after low pass filter 34 filtering high frequency, exports intermediate-freuqncy signal IFoutput.On the other hand, IF output signal IFoutput is compared with the reference voltage produced by digital to analog converter 302 by the intensity detection circuit 304 in AGC control module 35, the digital signal is relatively obtained by comparator 303, the output of demodulator 301 pairs of comparators 303 is sent to judge, if it is 11 that comparator exports, represent higher than high reference voltage VH, gain excessive needs reduces, it is 00 that comparator exports, represent lower than low reference voltage VL, gain too small needs increases, in addition comparator export be 10 all represents gain meet setting require not needs increase or minimizing, demodulator 301 is according to judging that comparator Output rusults produces the control signal of orderly ride gain adjustable low-noise amplifier 31 and radio frequency variable gain amplifier 32 Gain tuning.If it is that 11 that is amplitude output signal is excessive that comparator exports, first feedback loop controls radio frequency variable gain amplifier 32 and reduces gain, if the gain of radio frequency variable gain amplifier 32 is minimum, gain is reduced with regard to ride gain adjustable low-noise amplifier 31, the gain simultaneously arranging radio frequency variable gain amplifier 32 is maximum, and then continues the gain size reducing radio frequency variable gain amplifier 32.If it is that 00 that is amplitude output signal is too small that comparator exports, the gain that first feedback controls radio frequency variable gain amplifier 32 increases, if the gain of radio frequency variable gain amplifier 32 is maximum, the gain of ride gain adjustable low-noise amplifier 31 increases, the gain simultaneously arranging 32 radio frequency variable gain amplifiers 32 is minimum, and then continue the gain size increasing radio frequency variable gain amplifier 32, if the size of signal is in the stable region amplitude range of design, then keep gain-adjustable low-noise amplifier 31 and radio frequency variable gain amplifier 32 yield value constant.Automatic growth control realizes mainly needing to reduce excessive input signal, the process that too small input signal amplifies, wherein AGC control module plays the effect quantizing FEEDBACK CONTROL after the input signal after to amplification carries out amplitude detection, RSSI amplitude detection circuit in AGC control module can carry out detecting to intermediate frequency signal amplitude the analog quantization voltage swing exporting and obtain corresponding to signal amplitude, comparator can quantize the output voltage of amplitude detection circuit, the height reference voltage quantized is provided by DAC, the output of comparator is two-bit digital signal, whether the two-bit digital signal output voltage characterized now exceedes or is less than setting requirement, decoder 301 can draw the gain the need of increasing or reduce radio frequency amplifying circuit according to this two-bit digital signal, if need to increase gain, decoder 301 just stepping increase gain in original decoding gain digital controlling value, again new decoding gain digital controlling value is exported to radio-frequency amplifier circuit and control its gain size, if need to reduce gain, decoder 301 just stepping reduction gain in original decoding gain digital controlling value, again new decoding gain digital controlling value is exported to radio-frequency amplifier circuit and control its gain size.
Second embodiment
Fig. 4 gives a kind of radio frequency automatic gain control amplifier of the embodiment of the present invention, and this embodiment is the circuit block diagram that the present invention is applied to a kind of radio frequency automatic gain control amplifier formation block diagram of digital television radio-frequency front-end chip.By 41 gain-adjustable low-noise amplifiers, 42 radio frequency variable gain amplifiers, 44,45 down-conversion mixers, 46,47 low pass filters, 51 intensity detection circuit RSSI and 43 radio frequency automatic gain digitial controllers composition radio frequency automatic gain control loop, input signal V
iNNbe input to gain-adjustable low-noise amplifier 41, through the amplification of gain-adjustable low-noise amplifier 41, be input to radio frequency variable gain amplifier 42, through the amplification of radio frequency variable gain amplifier 42, then intermediate frequency is converted to by down-conversion mixer 44, intermediate-freuqncy signal by after low pass filter 46 filtering, then amplifies rear output by IF AGC control circuit 48.Wherein the output of low pass filter 46 detects through signal strength detection circuit 50, obtain the output voltage signal relevant to amplitude output signal, be supplied to radio frequency AGC digitial controller 43 to carry out judging and processing, radio frequency AGC digitial controller 43, according to the result of process, provides the control signal of ride gain adjustable low-noise amplifier 41 and radio frequency variable gain amplifier 42.The rf agc amplifier that Fig. 4 provides is the circuit of difference output structure, and the radio frequency automatic gain control loop provided is the circuit of single-path architecture.In the present embodiment, the major function of rf agc amplifier is: the gain of (1) ride gain adjustable low-noise amplifier 41 ensures to work in Linear Amplifer to input signal, and the noise factor of the front end of radio circuit can not be excessive.(2) gain of ride gain adjustable low-noise amplifier and rf gain variable amplifier, ensure under strong input signal condition, gain-adjustable low-noise amplifier 41 in radio-frequency (RF) front-end circuit, the circuit of down-conversion mixer 44 and low pass filter 46 can not be excessive and work in saturation condition due to input signal.The intermediate-freuqncy signal of the output of the low pass filter 46 and 47 in Fig. 4 send IF AGC control amplifier BB-AGC48 and 49 to do after intermediate frequency amplifies, and the middle frequency difference sub-signal that radio frequency automatic gain control amplifier exports delivers to the digital base band processor chip outside sheet.
Fig. 5 provides the adjustable gain low noise amplification level circuit diagram of the one-level difference in the second embodiment radio frequency automatic gain control amplifier.This gain-adjustable low-noise amplifier comprises the main amplifying stage of the difference be made up of M1 and M2, the load circuit of difference main amplifying stage M1 and the M2 that L1 and R3 and L2 and R4 is formed, the noise reducing structure realized by isolated DC electric capacity C1 and C2 and noise decrease inductance, and the low noise bypass structure path be made up of bypass resistance R5 and R6 inline bypass switching tube M3 and M4.Main amplifying stage Differential Input pipe M1 and M2, differential input end V
iNn and V
iNp through isolated DC electric capacity C1 and C2 separately correspondence be connected to the grid with M1 and M2, load circuit L1 and R3, L2 and R4 separately correspondence are connected between the drain electrode of differential input stage M1, M2 and power vd D, the sources connected in parallel of M1 with M2 is connected one end of noise decrease inductance L 3, the other end ground connection of L3, one end of biasing resistor R1, R2 connects the grid of M1 and M2, R1 respectively, the other end of R2 is attempted by bias voltage Bias1 and holds, for M1 and M2 provides bias voltage.Bias voltage Bias1 hold with ground between and meet a short switch pipe M5.Be connected in series by bypass resistance R5 and by-pass switch pipe M3, bypass resistance R6 and by-pass switch pipe M4 and form two road low noise bypass paths, between correspondence is connected to differential input end and exports.The grid of by-pass switch pipe M3 with M4 and short switch pipe M5 is connected bypass control signal Vctrl, and Vctrl is the gain control signal exported from radio frequency AGC control module.When Vctrl controls by-pass switch pipe M3 and M4 conducting, direct for large input signal bypass is exported, Vctrl controls short switch pipe M5 conducting simultaneously, to the gate bias voltage Bias1 of main amplifying stage be controlled directly by short switch pipe M5 ground connection, the grid voltage of winner amplifying stage M1 and M2 is made to be zero, M1 and M2 transistor turns off, and low noise amplifier gain is zero.When Vctrl controls by-pass switch pipe M3 and M4 and short switch pipe M5 closedown, low noise amplifier gain is current gain value G
l, thus, realize zero gain and yield value G with one-level low noise amplifier
lthe control that two kinds of fixed gains are adjustable.。
This gain-adjustable low-noise amplifier is by load circuit L1 and R3 comprising Differential Input amplifier tube M1 and M2 and M1, load circuit L2 and R4 of M2, and the path of biasing circuit and main amplifying stage M1 and M2 for the M5 switch that controls bias voltage, degenerative noise decrease inductance L 3 and comprise bypass resistance R5, R6 and switching tube M3, the bypass path composition of M4, selection function is amplified for providing two fixed gains for input signal, wherein connect the noise factor of negative feedback inductor L3 for reducing amplifying stage of amplifying stage source electrode, and improve the linearity of amplifying stage, the by-pass switch pipe M3 of low noise bypass path, the grid of M4 connects gain control signal Vctrl1, the break-make that control signal Vctrl1 controls by-pass switch pipe M3 with M4 realizes being separated of circuit configuration in main amplification path, control signal controls the short switch pipe M5 of the bias voltage of amplifying stage in main amplification path simultaneously, when the conducting of by-pass switch pipe, in main amplification path, amplifying stage is connected bias voltage and is operated in fixed gain magnifying state, and connect bypass path.When input signal is large-signal, control signal Vctrl1 controls by-pass switch pipe and disconnects, the bias voltage of the amplifier tube in main amplification path is set to zero, now main amplification path blockade, large-signal directly exports to the input of rear class variable gain amplifier by bypass path with zero gain, the signal exported keeps the good linearity because not being exaggerated, and reduces the noise factor of amplifying stage.
3rd embodiment
Fig. 6 a is the circuit structure block diagram of the signal strength detector of second embodiment of the invention, and the output signal providing the intensity detection circuit of Application Example of the present invention compares with VH and VL signal, produces the formation block diagram of digital controlled signal.VH and VL for provide comparator 62 realize subregion judge required for more electric, three inputs of comparator 62 are respectively from VH and the VL voltage that output voltage and the DAC of amplitude detection circuit 61 export.The output signal of amplitude detection circuit 61 and VH and the VL reference voltage signal produced by ADC digital to analog converter 63, be input to three inputs of comparator 62, comparator 62, according to the comparative result of three voltage signals, provides the output signal code of 2 bits simultaneously.Table 1 is the output signal code table of comparator 2 bit:
Table 1
| Output signal code | 11 | 10 | 00 | 01 |
| Comparative result | Gain is excessive | Gain is suitable | Gain is too small | - |
Outputing signal code 01 in table is situation about there will not be.
Fig. 6 a is given and is amplified by radio frequency amplifying circuit for input signal, frequency mixer mixing is in the concrete expression of three kinds of situations after being exported by filter again, be similar to above-mentioned explanation, wherein when radio frequency amplifying circuit amplifies, frequency mixer mixing can also continue to increase by the gain of filter output indication circuit in time crossing community again, output signal code corresponding to comparator in Fig. 4 is 00, when radio frequency amplifying circuit amplifies, frequency mixer mixing is just in time in the setting range of requirement by filter output gain of indication circuit when the stable region again, output signal code corresponding to comparator in Fig. 4 is 10, when radio frequency amplifying circuit amplifies, frequency mixer mixing needs to reduce to ensure that excessive signal can not make the circuit of the front end of radio frequency saturated by the gain of filter output indication circuit when the excessive district again, output corresponding to comparator in Fig. 4 is 11.The gain that can control radio-frequency front-end according to such comparative result reaches and can obtain optimum noise factor, again can not the object of saturation signal front end.
Fig. 6 b shows the relation between input voltage in the embodiment of the present invention and the output voltage detected by intensity detection circuit.In figure, " cross community " represents that the output voltage of amplification is less than VL after input signal amplifies, and the voltage that at this moment amplitude detection amplifying circuit detects is low with the comparative result of VL, and expression circuit gain at this moment can also continue increase.In figure, " stable region " represents after input signal amplifies, the output voltage amplified is greater than VL, be less than VH, at this moment the comparative result of the voltage that detects of amplitude detection amplifying circuit and VL is high and be low with the comparative result of VH, and the circuit gain representing at this moment needs to keep current yield value constant.In figure, " excessive district " represents that the output voltage of amplification is greater than VH after input signal amplifies, and at this moment the voltage that detects of amplitude detection amplifying circuit and the comparative result of VH are for high, and expression circuit gain at this moment needs minimizing.
Fig. 6 c provides the formation block diagram of the amplitude detection circuit in the embodiment of the present invention.As fig. 6 c: in embodiment, m value is 4.Amplitude detection circuit is by amplitude limiting amplifier circuit 61, and amplitude detection circuit unit 62 and voltage adder circuit 63 are formed.Amplitude limiting amplifier circuit 61 comprises the limited range enlargement level 602 ~ 605 of level Four cascade, amplitude detection circuit unit 62 comprises the amplitude detection level 606 ~ 610 of level Four cascade, the difference output end of the limited range enlargement level of every grade connects the differential input end of the amplitude detection level of corresponding one-level, the difference output end of every grade of amplitude detection level connects the input of voltage adder circuit 63, and the output of voltage adder circuit 63 is that last amplitude detection circuit exports.The intermediate-freuqncy signal exported by filter is reached capacity after being amplified by the amplifying circuit of the limited amplitude of level Four cascade, the output of the limited range enlargement level of every one-level all obtains the output of a voltage signal relevant to amplitude by the detection of amplitude detection circuit, the output of amplitude detection circuit each in 62 is carried out sum operation by 63 voltage adder circuits, obtain the voltage signal that can characterize input signal amplitude size, the size of this voltage signal directly just characterizes the size of input signal.
It will be understood by those skilled in the art that under the prerequisite not deviating from broad scope of the present invention, some changes are made to above-described embodiment.Thus, the present invention is not limited in disclosed specific embodiment.Its scope should contain appended claims limit core of the present invention and protection range in all changes.
Claims (5)
1. radio frequency automatic gain control amplifier, is characterized in that: radio frequency automatic gain control amplifier is called for short radio frequency AGC amplifier and comprises rf receiver unit and radio frequency amplification control unit and intermediate frequency amplifier; Wherein
Described rf receiver unit by a gain-adjustable low-noise amplifier LNA, a variable gain amplifier PGA, a down-conversion mixer and low pass filter are formed; The input of gain-adjustable low-noise amplifier circuit connects radio-frequency input signals RF
iNPUTthe output of gain-adjustable low-noise amplifier connects the input of variable gain amplifier, the output of variable gain amplifier connects the input of frequency mixer, the output of frequency mixer connects the input of low pass filter, and the output of low pass filter connects the input of radio frequency amplification control unit input and IF AGC control amplifier; Gain-adjustable low-noise amplifier LNA is connected the control signal output of radio frequency amplification control unit with the control end of variable gain amplifier PGA;
Described radio frequency amplification control unit is AGC control module, its input connects the output of the low pass filter of rf receiver unit, its two output correspondences connect the control end of gain-adjustable low-noise amplifier LNA and the control end of variable gain amplifier PGA, for realizing the control of radio frequency receiving element receiving gain;
The input of described intermediate frequency amplifier connects the output of the low pass filter of rf receiver unit, and its output connects next stage digital base band processor chip, amplifies for the intermediate-freuqncy signal exported low pass filter;
Described rf receiver unit and radio frequency amplification control unit and intermediate frequency amplifier are difference channel structure;
Described gain-adjustable low-noise amplifier by main amplifying stage, load circuit, noise decrease inductance and low noise bypass structure composition; Low noise bypass structure comprises the bypass resistance and by-pass switch pipe that two tunnels are connected in series, the two port of the bypass resistance that two tunnels are connected in series and by-pass switch pipe should be attempted by between Two-pass DINSAR input and difference output end, and the control end of by-pass switch pipe connects bypass control signal;
Low noise bypass structure also comprises a bias voltage short switch pipe, and between the biased electrical pressure side that bias voltage short switch pipe is attempted by the input pipe grid of main amplifying stage and ground, the control end of short switch pipe connects bypass control signal; By-pass switch pipe and short switch pipe are controlled by bypass control signal simultaneously, control to access a bypass resistance by by-pass switch pipe between main amplifying stage Two-pass DINSAR input and difference output end, control main amplifying stage input pipe gate bias voltage directly by short switch pipe ground connection simultaneously, input pipe is turned off, exporting through bypass structure with zero gain and low noise at main amplifying stage for controlling large input signal, realizing one-level low noise amplifier and zero gain or fixed gain G are provided
lthe controlled coarse adjustment of two kinds of yield values is selected: G
lvalue is several times as much as the gain step value of variable gain amplifier PGA.
2. radio frequency automatic gain control amplifier according to claim 1, is characterized in that: the circuit composition of described radio frequency amplification control unit comprises signal strength detector RSSI, digital to analog converter DAC, comparator and demodulator Decoder; Wherein
Described signal strength detector RSSI is signal strength indicator circuit, be used for detect and instruction intermediate-freuqncy signal intensity;
Described digital to analog converter DAC, is converted to fixing analog signal voltage for Reference Signal;
Described comparator is two input terminal comparators, makes comparisons for fixed signal voltage signal strength detector output voltage and DAC exported, and exports a comparative result;
Described demodulator Decoder is digital demodulating circuit, and the digital signal for being inputted by comparator carries out processing the control signal that rear decoding exports the concrete gain size of ride gain adjustable low-noise amplifier LNA and variable gain amplifier PGA;
The input of signal strength detector RSSI connects the output of low pass filter, its output connects the signal input part of comparator, the output of digital to analog converter DAC connects the fixed reference potential input of comparator, the input of demodulator Decoder connects the output of comparator, and two output correspondences of demodulator Decoder connect a control end in LNA and PGA.
3. radio frequency automatic gain control amplifier according to claim 1, is characterized in that: described variable gain amplifier comprises several variable gain amplifying stage circuit; Each variable gain amplifying stage has gain control end, and the gain control end of each variable gain amplifying stage connects the same control signal output of radio frequency amplification control unit, and this control signal is digital controlled signal;
Several variable gain amplifying stage circuit are differential series syndeton, two-way radio-frequency differential input signal connects two differential input ends of first order variable gain amplifying stage circuit, and two difference output ends of final stage variable gain amplifying stage circuit connect radio frequency amplification control unit input and digital baseband chip differential input end; Each variable gain amplifying stage is the gain step value G of identical current gain value and variable gain amplifier
s, the maxgain value of variable gain amplifier is mG
s, m be greater than 2 positive integer.
4. radio frequency automatic gain control amplifier according to claim 2, it is characterized in that: described comparator circuit is 2bit digital comparator, the output port of input connection signal intensity detector, the voltage compare different from two height by the output voltage of signal strength signal intensity, obtain the digital output signal of 2bit, adopt the size of the result characterization signal intensity output voltage compared, represent that signal strength signal intensity is greater than high voltage VH when comparator exports 11, when the output 10 of comparator represents that signal strength signal intensity meets the demands between VL and VH, when the output of comparator is that the satisfied setting requirement of 00 expression signal strength signal intensity is less than VL.
5. radio frequency automatic gain control amplifier according to claim 1, it is characterized in that: described low pass filter is fourth order low-pass filter construction, be made up of resistive degeneration and electric capacity and amplifier unit, its input receives the output signal from frequency mixer, the radio-frequency component in filtered signal.
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| CN115173884A (en) * | 2022-06-16 | 2022-10-11 | 中国船舶集团有限公司第七二三研究所 | Automatic gain control MISO radio frequency signal switch network |
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Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101162912A (en) * | 2007-11-19 | 2008-04-16 | 上海士康射频技术有限公司 | Single chip radio frequency transceiver |
| CN102064841A (en) * | 2009-11-16 | 2011-05-18 | 杭州士兰微电子股份有限公司 | Amplitude shift keying (ASK)/on-off keying (OOK) radio frequency (RF) receiving circuit |
-
2011
- 2011-07-05 CN CN201110186734.XA patent/CN102868369B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101162912A (en) * | 2007-11-19 | 2008-04-16 | 上海士康射频技术有限公司 | Single chip radio frequency transceiver |
| CN102064841A (en) * | 2009-11-16 | 2011-05-18 | 杭州士兰微电子股份有限公司 | Amplitude shift keying (ASK)/on-off keying (OOK) radio frequency (RF) receiving circuit |
Non-Patent Citations (3)
| Title |
|---|
| .《2005 IEEE.》.2005, * |
| Chua-Chin Wang等.Wideband 70dB CMOS Digital Variable Gain Amplier Design for DVB-T Receiver"s AGC􀀀 * |
| CMMB 系统中RSSI 电路设计;庄海孝等;《浙江大学学报(工学版)》;20110530;1-7 * |
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