CN102255626B - Pi-network-based millimeter wave frequency band receiver with electrostatic discharge protection function - Google Patents

Abstract

The invention discloses a pi-network-based millimeter wave frequency band receiver with an electrostatic discharge protection function, and belongs to the field of radio frequency and millimeter wave integrated circuit designing. The receiver comprises an electrostatic discharge (ESD) protection circuit consisting of back biased diodes, a low-noise amplifier (LNA) in a two-stage amplification structure, mixers of branch circuits I and Q, gain variable amplifiers of the branch circuits I and Q, a balun and an output ESD protection circuit consisting of the back biased diodes. Connection relationships among the circuits are that: the ESD protection circuit is connected in series with the LNA; the other end of the ESD protection circuit is an input end; the other end of the LNA is connected with the common input end of the two mixers of the branch circuits I and Q; the input end of the balun is a local oscillation (LO) end, and the output end of the balun is connected with the two local oscillation signal input ends of the mixer of the branch circuit I; the output ends of the mixers of the branch circuits I and Q are connected with the input ends of the gain variable amplifiers of the two branch circuits respectively; and the output ends of the gain variable amplifiers are connected to the final output end of the circuit after passing through the ESD protection circuit. By the invention, the electrostatic reliability of the circuit of the receiver can be ensured, and the overall performance of broadband input matching, high gain and low noise of the receiver can be improved.

Description

A kind of millimeter wave frequency band receiver that has electrostatic discharge (ESD) protection based on ∏ type network

Technical field

The invention belongs to radio frequency and millimetre integrated circuit design field, particularly high reliability, the high performance receiver that has the Electrostatic Discharge protection.

Background technology

Along with CMOS (complementary metal-oxide-semiconductor: the development of high-speed radio communicating circuit and system Complementary Metal-Oxide-Semiconductor), with user's improving constantly requirements such as communication quality and speed experience, information exchange speed constantly increases, and especially the indoor high-speed communication requirement becomes more and more for important.According to the Mason prediction, by 2016,80% of global radio amount of communication data will be by indoor generation.Under such background, for breaking through the bottleneck of low-frequency spectra scarcity of resources, radio communication enters radio frequency, microwave and millimetre-wave attenuator epoch, V-band, W wave band and the D wave band of millimeter wave and submillimeter wave have been reached at present, wherein with the most representative based on radio communication and the radar communication of wave bands such as 24GHz, 60GHz, 77GHz and 94GHz, communication data rate can reach Gbps (Giga-bit-per-second) and more than, thereby attracted academia and industrial quarters personage's extensive concern.

Specific to the wireless receiver system that is operated in microwave and millimeter wave band, high-gain, low noise need be realized, with loss and the noise factor of the whole receiver system of balance under high frequency when satisfying low cost, low-power consumption.Simultaneously; development along with CMOS technology; transistorized gate oxide thickness reduces gradually, and puncture voltage constantly reduces, and the contradiction between the electrostatic protection of circuit and reliability design and the high frequency input terminal parasitic capacitance has brought very big challenge for the design of receiver system.For example, the influence to circuit under low frequency of the esd protection electric capacity of a 100fF can be ignored, but will introduce 66 Ω even lower impedance under 24GHz even higher frequency range, and this will have a strong impact on the overall performance of receiver circuit.Conventional method is paid attention to broadband and low noise design more about the design of microwave and millimeter wave receiver, and the design of relevant ESD is separately carried out often, considers slightly under the situation that guarantees the radio circuit performance or does not consider substantially.Related work see reference document " F.Vecchi, S.Bozzola, M.Pozzoni, D.Guermandi, E.Temporiti, M.Repossi, U.Decanis, A.Mazzanti, and F.Svelto, " A Wideband mm-Wave CMOS Receiver for Gb/s Communications Employing Interstage Coupled Resonators, " IEEE IS SCC Dig.Tech.Papers, Feb.2010, pp.220-221. " with " T.Yao, M.Gordon, K.Tang, K.Yau, M.-T.Yang, P.Schvan, and S.P.Voinigescu, " Algorithmic design of CMOS LNAs and Pas for 60-GHz radio; " IEEE J.Solid-State Circuits, vol.42, no.5, pp.1044-1057, May 2007. ".The wireless receiver system of high reliability and high robust; except require the designer on the circuit structure with the innovation that improves in the ghost effect; also need at the key issue in this receiver system design of esd protection circuit in addition well-designed; properly settle the contradiction between esd protection circuit and the parasitic capacitance, guarantee the reliability of whole receiver system.

The esd protection circuit that is applied at present in the radio system mainly contains two kinds of forms.A kind of is by introducing the impedance shielding that LC resonant tank or T-coil matching network carry out ESD, correlative study document " the M.-D.Ker that sees reference, C.-I.Chou, and C.-M.Lee, " A novel LC-tank ESD protection design for gigahertz RF circuits; " in Proc.Radio Frequency Integr.Circuits Symp. (RFIC), Jun.2003, pp.115-118. ", " S.Galal and B.Razavi, " Broadband ESD protection circuits in CMOS technology; " IEEE J.Solid-State Circuits, vol.38, no.12, pp.2334-2340, Dec.2003. " and " B.J.Huang, C.H.Wang, C.C.Chen, M.F.Lei, P.C.Huang, K.Y.Lin, and H.Wang. " Design and Analysis for a 60-GHz Low-Noise Amplifier With RF ESD Protection; " IEEE Trans.Microw.Theory Tech., vol.57, No.2, pp.298-305, Feb.2009. ".Another kind of mode is that the parasitic capacitance in the esd protection circuit is taken in the input impedance matching network; as list of references " M.-D.Ker and B.-J.Kuo; " Decreasing-size distributed ESD protection scheme for broadband RF circuits; " IEEE Trans.Microw.Theory Tech.; vol.53; No.2; pp.582-589; Feb.2006. " adopted the discrete circuitry framework in; even but transmission circuit network wherein also can take bigger chip area at millimeter wave band, practicality is not strong.

Therefore; at the wireless receiver system that is operated in microwave and millimeter wave band; properly settle the contradiction between esd protection circuit and the receiver input high frequency node parasitic capacitance; be the key issue that needs to be resolved hurrily in the radio circuit design, with designed reliability and the static robustness that guarantees whole receiver system.

Summary of the invention

In view of this; the objective of the invention is to for overcoming the weak point of prior art; a kind of millimeter wave frequency band receiver that has esd protection based on ∏ type network is proposed; realize at the same time on the basis of impedance matching preferably and noise coupling; guarantee low-noise factor and high-conversion-gain; with realize commercial integrated circuit standard ± 2kV HBM (manikin: static robustness Human-Body Model), improve the designed reliability of whole receiver system.

For realizing above purpose, the present invention proposes a kind of millimeter wave frequency band receiver that has esd protection based on ∏ type network: it is characterized in that, adopt the zero intermediate frequency framework, produce the output of I and Q two paths of signals respectively with two frequency mixers, this receiver comprises: the esd protection circuit of being made up of back biased diode, the low noise amplifier of two-stage structure for amplifying (Low Noise Amplifier:LNA), the frequency mixer of I branch road and Q branch road (Mixer), the variable gain amplifier of I branch road and Q branch road (Variable Gain Amplifier:VGA), the output esd protection circuit that Ba Lunhe is made up of back biased diode; The annexation of each several part circuit is as follows: esd protection circuit is connected with LNA, and input radio frequency signal low noise is amplified, and the other end of esd protection circuit is I, the public input of Q frequency mixer of two branch roads of another termination of input, LNA; Ba Lun will import single-ended signal and be converted to differential signal, and its input is two inputs of local oscillation signal of LO end, output termination I branch road frequency mixer; I, Q two-way frequency mixer will be down-converted to zero intermediate frequency by the radiofrequency signal of LNA output; its output connects the input of the variable gain amplifier of 2 branch roads respectively; variable gain amplifier is used for realizing the adjusting of signal gain on I, Q two branch roads, and the variable gain amplifier output is received the final output of circuit behind esd protection circuit.

The described LNA that has esd protection circuit can comprise 4 nMOS pipe M ₁, M ₂, M ₃And M ₄, draw diode D on two ESD _N1And D _N2, two ESD pull-down diode D _P1And D _P2, 5 inductance L _g, L _s, L _D1, L _D2And L _p, 3 capacitance C _p, C _C1And C _C2Its annexation is: inductance L _gA termination input, another termination nMOS manages M ₁The grid end; Draw diode D on two ESD _N1And D _N2Public termination power vd D, two ends meet L respectively in addition _gTwo ends.Two ESD pull-down diode D _P1And D _P2Public termination GND, two ends meet L respectively in addition _gTwo ends; NMOS manages M ₁Source electrode connects inductance L _sAn end, inductance L _sAnother termination GND; NMOS manages M ₂Source electrode meets M ₁Drain electrode, grid meets VDD, M ₂Drain electrode connect inductance L _D1An end, L _D1Another termination power vd D.Inductance L _pA termination M ₁Drain electrode, another termination capacitance C _pAn end, C _pOther end ground connection GND; M ₂Drain electrode meet capacitance C _C1An end, C _C1Another termination nMOS pipe M ₃Grid; M ₃Source ground GND, drain electrode meets nMOS pipe M ₄Source electrode, M ₄Grid meet power vd D, M ₄Drain electrode connect inductance L _D2An end, L _D2Another termination power vd D; M ₄Drain electrode meet capacitance C _C2An end, C _C2The input of another termination frequency mixer.

Technical characterstic of the present invention and beneficial effect:

The millimeter wave frequency band receiver that has an esd protection based on ∏ type network that the present invention proposes has been realized higher peak value conversion gain, and has realized lower insertion loss at 21.5GHz in the scope of 25GHz, has embodied good impedance matching property.Guaranteed that noise objective has preferably satisfied the esd protection requirement of commercial integrated circuit, has verified the ESD reliability of circuit.

Compare with similar receiver; the 24GHz millimeter wave frequency band receiver that has an esd protection based on ∏ type network that utilizes that the present invention proposes has overwhelming superiority in high-gain and low-power consumption; and has a better linearity degree; and noise factor does not significantly reduce; the reliability of esd protection circuit has reached the standard of commercialization ± 2kV; similar be best index at present in based on the work of CMOS technology, thereby verified correctness of the present invention, actual effect and at the ESD robustness of commercial integrated circuit standard.

Description of drawings

Fig. 1 is the circuit theory diagrams of the 24GHz millimeter wave frequency band wireless receiver that has esd protection in the embodiment of the invention;

Fig. 2 is the circuit theory diagrams of the LNA that has ∏ type impedance matching network esd protection circuit that adopts in the receiver;

Fig. 3 is at local oscillation signal 0dBm, and receiver inserts the test result of loss and conversion gain during IF frequency 100MHz;

Fig. 4 is at local oscillation signal 0dBm, the test result of receiver noise factor during IF frequency 100MHz;

Fig. 5 is at local oscillation signal 0dBm, the test result of receiver 1dB compression point during IF frequency 100MHz.

Embodiment

For making purpose of the present invention, technical scheme and characteristics more explicit, the present invention is described in detail and description below in conjunction with the drawings and the specific embodiments.

The present invention proposes a kind of millimeter wave frequency band receiver that has esd protection based on ∏ type network; adopt the zero intermediate frequency framework; adopt two frequency mixers to produce I and the output of Q two paths of signals respectively; as shown in Figure 1, this receiver comprises: variable gain amplifier IV, the Ba Lun V of 2 frequency mixer III, I branch road and the Q branch road of the esd protection circuit I that is made up of two back biased diodes, LNA II (its every grade concrete structure as shown in Figure 2), I branch road and the Q branch road of secondary structure for amplifying and the output esd protection circuit VI that is made up of back biased diode.Wherein frequency mixer and variable gain amplifier adopt normal structure to realize.Whole receiver is realized the high-frequency signal of millimeter wave frequency band is downconverted to zero intermediate frequency, then exports follow-up baseband circuit demodulation to.

The annexation of each several part circuit is as follows: esd protection circuit I connects with LNA II, input radio frequency signal low noise is amplified, and the other end of esd protection circuit (left end) is the public input 101 of I, Q frequency mixer that input in, the LNA II other end (right-hand member) connect two branch roads; Ba Lun will import single-ended signal and be converted to differential signal, and its input is the local oscillation signal input 102 and 103 of LO end, output termination I branch road frequency mixer.I, Q two-way frequency mixer III will be down-converted to zero intermediate frequency by the radiofrequency signal of LNA output; its output connects the input of the variable gain amplifier (Variable Gain Amplifier:VGA) of 2 branch roads respectively; VGA is used for realizing the adjusting of signal gain on I, Q two branch roads, and its output is received the final output out of circuit behind esd protection circuit VI.

The described LNA that has esd protection circuit, its embodiment of circuit structure comprises 4 nMOS pipe M as shown in Figure 2 ₁, M ₂, M ₃And M ₄, draw diode D on two ESD _N1And D _N2, two ESD pull-down diode D _P1And D _P2, 5 inductance L _g, L _s, L _D1, L _D2And Lp, 3 capacitance C _p, C _C1And C _C2Its annexation is: inductance L _gA termination input, another termination nMOS manages M ₁The grid end; Draw diode D on two ESD _N1And D _N2Public termination power vd D, two ends meet L respectively in addition _gTwo ends.Two ESD pull-down diode D _P1And D _P2Public termination GND, two ends meet L respectively in addition _gTwo ends; NMOS manages M ₁Source electrode connects inductance L _sAn end, inductance L _sAnother termination GND; NMOS manages M ₂Source electrode meets M ₁Drain electrode, grid meets VDD, M ₂Drain electrode connect inductance L _D1An end, L _D1Another termination power vd D.Inductance L _pA termination M ₁Drain electrode, another termination capacitance C _pAn end, C _pOther end ground connection GND; M ₂Drain electrode meet capacitance C _C1An end, C _C1Another termination nMOS pipe M ₃Grid; M ₃Source ground GND, drain electrode meets nMOS pipe M ₄Source electrode, M ₄Grid meet power vd D, M ₄Drain electrode connect inductance L _D2An end, L _D2Another termination power vd D; M ₄Drain electrode meet capacitance C _C2An end, C _C2The input of another termination frequency mixer.

This circuit structure is with the collaborative consideration in whole design of LNA module and esd protection circuit in the receiver, ESD parasitic capacitance (diode D _N1, D _N2, D _P1And D _P2On electric capacity) be decomposed into ∏ type network, with impedance matching and the design of noise coupling that realizes circuit.Compare with traditional ESD impedance screen method, this structure has reduced the loss on the signal path when realizing the circuit coupling, improved circuit gain and reduced noise factor.

It is embodiment at the wireless receiver circuit that is operated in the 24GHz millimeter wave frequency band that the present invention adopts 0.13 μ m RF-CMOS technology, its circuit theory as shown in Figure 1, 2, wherein radiofrequency signal is converted to baseband signal through the mode that LNA amplifies by zero intermediate frequency, the local oscillation signal LO of frequency mixer is provided by sheet external signal source, and Ba Lun is converted to differential signal on sheet, baseband signal is amplified to the baseband signal amplitude through VGA, and its gain can be adjusted between the 10dB at-5dB, and OIP3 is greater than 10dBm.The LNA key parameter and the index that have esd protection circuit in the present embodiment are listed in following table:

The concrete parameter determination method of the above-mentioned LNA that has esd protection circuit is described as follows:

A. determine the input pipe M of LNA in the receiver ₁Current offset, namely current density 0.2mA/ μ m is the lowest noise coefficient current density of CMOS technology.

B determines optimum source impedance R by the equilibrium analysis between gain, power consumption and noise factor _Sopt, and then definite transistor size.

C determines source degeneracy inductance L _sTo satisfy the optimum source impedance coupling.

D is determined the size of diode in the esd protection circuit namely to obtain C by the esd protection electric pressure _ESD(C _P1+ C _P2).

E finishes by R by ∏ type impedance matching network _sTo R _SoptThe impedance conversion, determine C _P1, C _P2And L _gSize Deng component parameters and two esd protection diodes.

The f inductance L _D1And L _D2Value need load capacitance resonance with the back level on centre frequency (being 24GHz in the present embodiment), inductance L _pValue need and M ₂Grid source capacitor resonance on centre frequency (being 24GHz in the present embodiment), capacitance C _C1, C _C2And C _pValue require to get final product far below 50 Ω in the equiva lent impedance that centre frequency (being 24GHz in the present embodiment) is located.

Be noise voltage based on non-quasistatic (Non-Quasi Static:NQS) electric-resistivity method with the grid noise equivalent in the foregoing circuit design

With resistance r _NqsSeries connection, concrete theoretical foundation can be with reference to " T.H.Lee, The Design of CMOS Radio-Frequency Integrated Circuits, 2nd ed.Cambridge, U.K.:Cambridge Univ.Press, 1998. ", wherein k is Boltzmann constant, T is temperature, and δ is the grid noise factor.

According to the LNA circuit structure among Fig. 2, derive input common source pipe M ₁Optimal source impedance Z _Opt=R _Sopt+ jX _OptWith minimal noise coefficient F _Min, the formula that embodies is suc as formula shown in (1)～(3),

$R_{\mathrm{sopt}}=\sqrt{\frac{R_{\mathrm{Gf}}(1+\frac{\mathrm{\&gamma;}}{\mathrm{\&alpha;}}{\left(\frac{\mathrm{\&omega;}}{{\mathrm{\&omega;}}_T}\right)}^2{R}_{\mathrm{Gf}}{g}_{\mathrm{mf}})}{\frac{\mathrm{\&gamma;}}{\mathrm{\&alpha;}}{g}_{\mathrm{mf}}{\left(\frac{\mathrm{\&omega;}}{{\mathrm{\&omega;}}_T}\right)}^2{\mathrm{<figure-callout\; id="2"\; label="N\; f"\; filenames="HDA0000072728210000021.png"\; state="\{\{state\}\}">N</figure-callout>}}_f^{}}}=\frac{R_{\mathrm{soptf}}}{N_f}---\left(1\right)$

$j{X}_{\mathrm{opt}}=-\frac{1}{\mathrm{j\&omega;}{C}_{\mathrm{gs}}}=\frac{X_{\mathrm{optf}}}{N_f}---\left(2\right)$

$F_{\min }-1=2\sqrt{\left(\frac{\mathrm{\&gamma;}}{\mathrm{\&alpha;}}{g}_{\mathrm{mf}}{R}_{\mathrm{Gf}}{\left(\frac{\mathrm{\&omega;}}{{\mathrm{\&omega;}}_T}\right)}^2(1+\frac{\mathrm{\&gamma;}}{\mathrm{\&alpha;}}{g}_{\mathrm{mf}}{R}_{\mathrm{Gf}}{\left(\frac{\mathrm{\&omega;}}{{\mathrm{\&omega;}}_T}\right)}^2)\right)}+2\frac{\mathrm{\&gamma;}}{\mathrm{\&alpha;}}{g}_{\mathrm{mf}}{R}_{\mathrm{Gf}}{\left(\frac{\mathrm{\&omega;}}{{\mathrm{\&omega;}}_T}\right)}^2---\left(3\right)$

R wherein _SoptBe optimum source resistance, jX _OptBe the reactance of optimum source.r _gBe gate resistance, N _fBe interdigital number, g _MfAnd R _GfBe single interdigital mutual conductance and gate resistance, α is the relevant parameter of technology with γ, ω _TBe transistorized cut-off angular frequency, ω is angular frequency, R _SoptfBe single interdigital optimum source resistance, X _OptfBe single interdigital optimum source reactance, C _GsBe transistor M ₁Grid source electric capacity.

By adding source degeneracy inductance L _sMethod with gate resistance R _G=r _g+ r _NqsBe matched to R _Sopt, satisfy R _Sopt-R _G=ω _TL _s, r wherein _gSquare resistance for grid.As shown in Figure 2, the parasitic capacitance on the ESD is decomposed into C _P1And C _P2, and introduce grid series inductance L _gForm ∏ type matching network.Utilize following relation to finish impedance matching, R _IBe the interlaminated resistance of network, R _sBe source resistance:

$R_I=R_s\frac{1}{1+{\left(\mathrm{\&omega;}{R}_s{C}_{p1}\right)}^2}$ (4)

$R_I=R_{\mathrm{sopt}}{\left(\frac{C_{\mathrm{<figure-callout\; id="2"\; label="gs\; C\; p"\; filenames="HDA0000072728210000021.png"\; state="\{\{state\}\}">gs</figure-callout>}}}{C_p}\right)}^2$

The gain of whole LNA with

Be inversely proportional to, as the formula (5), R wherein _LBe load resistance, thereby the gain of adopting the impedance match method of non-50 Ω can improve circuit, but need consider with the power consumption of circuit is compromise.On the other hand, in the receiver noise factor of LNA by common source pipe M among Fig. 2 ₁, L _gProvide low excessively R with ESD three aspects _OptCan improve the contribution of the LNA noise factor of ESD, as the formula (6), thereby, there is a R _OptOptimal value, in optimization of the present invention, adopted the optimum source impedance of 30 Ω, make receiver noise of introducing ESD when realizing high-gain with exceeding.

$\mathrm{Gain}=\frac{1}{2\sqrt{R_{\mathrm{sopt}}{R}_s}}\frac{{\mathrm{\&omega;}}_T}{\mathrm{\&omega;}}{R}_L---\left(5\right)$

$F_{\mathrm{network}}-1=\frac{\mathrm{\&omega;}{R}_s{C}_{p1}}{Q_{\mathrm{ESD}}}+\frac{\mathrm{\&omega;}{L}_g}{Q_{\mathrm{Lg}}{R}_i}+\frac{{\mathrm{<figure-callout\; id="2"\; label="C\; p"\; filenames="HDA0000072728210000021.png"\; state="\{\{state\}\}">C</figure-callout>}}_p}{\mathrm{\&omega;}{(C_{\mathrm{gs}}+C_{p2})}^2{Q}_{\mathrm{ESD}}{R}_{\mathrm{sopt}}}---\left(6\right)$

Q in the formula _ESDAnd Q _LgBe ESD and L _gQuality factor, F _NetworkBe overall noise factor.

The remainder circuit of present embodiment: frequency mixer, Ba Lun, variable gain amplifier, power clamping device all adopt the circuit structure of standard to realize.

By the key index of receiver of the present invention has been carried out test analysis as inserting loss, conversion gain, noise factor and 1dB compression point etc., its result with the curve of frequency change respectively at providing among Fig. 3, Fig. 4 and Fig. 5.Solid circles represents the test result of gain (S21) under the high gain mode among Fig. 3, and triangle represents the test result of gain (S21) under the low gain mode, and return loss (S11) result of empty circles representative input.Circle represents the test result of the noise factor (NF) under the high gain mode among Fig. 4, and triangle represents the test result of noise factor under the low gain mode (NF).Circle represents the test result of intermediate frequency power output under the high gain mode among Fig. 5, and triangle represents the test result of intermediate frequency power output under the low gain mode.

From test result; the embodiment that has a millimeter wave frequency band receiver of esd protection based on ∏ type network that the present invention proposes has realized the peak value conversion gain of the minimum 21dB of the highest 36dB; and realized in the scope of 25GHz at 21.5GHz-insertion loss below the 12dB, embodied good impedance matching property.Under radio frequency and intermediate frequency under three dB bandwidth be respectively 1GHz and 150MHz.The minimal noise coefficient that obtains of test is 6.5dB, and is 6.8dB at 22GHz average noise factor in the frequency band of 24GHz, has also guaranteed noise objective preferably.Output 1dB compression point is respectively 2dBm and 2.3dBm under high-gain and low gain mode.In the test of ESD; from the radio-frequency head to the power supply and the discharge path of ground end can bear ± the ESD potential pulse of 2kV, width is 100ns, rises and is 10ns fall time; this has satisfied the esd protection requirement of commercial integrated circuit, has verified the ESD reliability of circuit.

Compare with similar receiver; the 24GHz millimeter wave frequency band receiver that has an esd protection based on ∏ type network that utilizes that the present invention proposes has overwhelming superiority in high-gain and low-power consumption; and has a better linearity degree; and noise factor does not significantly reduce; the reliability of esd protection circuit has reached the standard of commercialization ± 2kV; similar be best index at present in based on the work of CMOS technology, thereby verified correctness of the present invention, actual effect and at the ESD robustness of commercial integrated circuit standard.

In a word, the above only for the present invention under the concrete CMOS technology with concrete 24GHz millimeter wave frequency band under the checking example of wireless receiver, be not for limiting protection scope of the present invention.

Claims (1)

1. millimeter wave frequency band receiver that has esd protection based on Π type network, it is characterized in that, adopt the zero intermediate frequency framework, produce the output of I and Q two paths of signals respectively with two frequency mixers, this receiver comprises: variable gain amplifier, the Ba Lun of frequency mixer, I branch road and the Q branch road of the esd protection circuit of being made up of back biased diode, LNA, I branch road and the Q branch road of two-stage structure for amplifying and the output esd protection circuit of being made up of back biased diode; The annexation of each several part circuit is as follows: esd protection circuit is connected with LNA, and input radio frequency signal low noise is amplified, and the other end of esd protection circuit is I, the public input of Q frequency mixer of two branch roads of another termination of input, LNA; Ba Lun will import single-ended signal and be converted to differential signal, and its input is two inputs of local oscillation signal of LO end, output termination I branch road frequency mixer; I, Q two-way frequency mixer will be down-converted to zero intermediate frequency by the radiofrequency signal of LNA output, its output connects the input of the variable gain amplifier of 2 branch roads respectively, variable gain amplifier is used for realizing the adjusting of signal gain on I, Q two branch roads, and the variable gain amplifier output is received the final output of circuit behind esd protection circuit;

The LNA that has esd protection circuit comprises 4 nMOS pipe M ₁, M ₂, M ₃And M ₄, draw diode D on two ESD _N1And D _N2, two ESD pull-down diode D _P1And D _P2, 5 inductance L _g, L _s, L _D1, L _D2And L _p, 3 capacitance C _p, C _C1And C _C2Its annexation is: inductance L _gA termination input, another termination nMOS manages M ₁The grid end; Draw diode D on two ESD _N1And D _N2Public termination power vd D, two ends meet L respectively in addition _gTwo ends; Two ESD pull-down diode D _P1And D _P2Public termination GND, two ends meet L respectively in addition _gTwo ends; NMOS manages M ₁Source electrode connects inductance L _sAn end, inductance L _sAnother termination GND; NMOS manages M ₂Source electrode meets M ₁Drain electrode, grid meets VDD, M ₂Drain electrode connect inductance L _D1An end, L _D1Another termination power vd D, inductance L _pA termination M ₁Drain electrode, another termination capacitance C _pAn end, C _pOther end ground connection GND; M ₂Drain electrode meet capacitance C _C1An end, C _C1Another termination nMOS pipe M ₃Grid; M ₃Source ground GND, drain electrode meets nMOS pipe M ₄Source electrode, M ₄Grid meet power vd D, M ₄Drain electrode connect inductance L _D2An end, L _D2Another termination power vd D; M ₄Drain electrode meet capacitance C _C2An end, C _C2The input of another termination frequency mixer.

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