CN103338008A - Wide/intermediate frequency MMW (Millimeter Wave) double-balance passive frequency mixer - Google Patents

Abstract

The invention discloses a wide/intermediate frequency MMW (Millimeter Wave) double-balance passive frequency mixer. According to the wide/intermediate frequency MMW double-balance passive frequency mixer disclosed by the invention, a transconductance stage of a traditional active double-balanced mixer is replaced by utilizing an inductor and a serial-connection network at an unbalance end of a Marchand Balun which is arranged at a radio frequency input end, and passive frequency mixing is realized; and in addition, a local oscillation signal can be in frequency mixing with a radio frequency signal which is injected from a source electrode through a grid electrode of a frequency mixing transistor subjected to peak inductance injection after being changed into a differential signal through a Marchand Balun at a local oscillation input end.

Description

The two balanced passive mixers of a kind of millimeter wave of wide intermediate frequency

Technical field

The present invention relates to passive frequency mixer, the two balanced passive mixers of especially a kind of millimeter wave of wide intermediate frequency can be used for the mixing of 31～45GHz integrated RF receiver front end signal, the occasion that needs produce the wide intermediate frequency of 1～14GHz, belong to the radio-frequency technique field.

Background technology

The essence of transceiver analog radio frequency front end is to finish the function of frequency translation, the receiver radio frequency front end is the radiofrequency signal that receives will be converted to low frequency signal, and the transmitter radio-frequency front-end to be the low frequency signal of wanting to launch convert high-frequency signal to, this frequency translation function is finished by frequency mixer.In the millimeter wave receiver front end, passive frequency mixer has very high research and using value with the advantage of its zero-power, high linearity.But conversion loss is big, the narrower bottleneck that becomes the application of restriction passive frequency mixer of intermediate-frequency bandwidth.Passive frequency mixer commonly used has two kinds of structures: single balanced structure and two balanced structure.Single balanced structure design is simple relatively but the mixing distortion is bigger, and two balanced structures design relative complex but the mixing distortion is less.

Summary of the invention

The present invention is based on two passive mixing of balance, a kind of two balanced passive mixers of millimeter wave of wide intermediate frequency are proposed, utilize the transconductance stage of the alternative traditional active double balanced mixer of series network of inductance and the non-equilibrium end of rf inputs Marchand Ba Lun, realize passive mixing.In addition, local oscillation signal injects the grid of mixing transistor and the radiofrequency signal mixing that source electrode injects by peaking inductance after local oscillator input Marchand Ba Lun becomes differential signal.Through inventor's retrieval, two balanced passive mixers of this kind structure are still undiscovered.

The present invention adopts following technical scheme: the two balanced passive mixers of a kind of millimeter wave of wide intermediate frequency is characterized in that: comprise four mixing NMOS pipes M1, M2, M3, M4, rf inputs Marchand Ba Lun, a local oscillator input Marchand Ba Lun, four inductance L _Rf1, L _Rf2, L _Lo1, L _Lo2, two capacitance C1, C2, two biasing resistor R1, R2 and an active Ba Lun; Radiofrequency signal is converted into a pair of differential signal at non-equilibrium end and is passed through inductance L respectively by the balance end input of rf inputs Marchand Ba Lun _Rf1And L _Rf2Connect the source electrode of NMOS pipe M1, M2 and the source electrode of NMOS pipe M3, M4, the drain electrode of NMOS pipe M1 connects the drain electrode of NMOS pipe M3 and is connected with the input of active Ba Lun, the drain electrode of NMOS pipe M2 connects the drain electrode of NMOS pipe M4 and is connected with another input of active Ba Lun, local oscillation signal is converted into a pair of differential signal at non-equilibrium end and is connected biasing resistor R1 and inductance, L with C2 through capacitance C1 respectively by the balance end input of local oscillator input Marchand Ba Lun _Lo1An end and biasing resistor R2 and inductance, L _Lo2An end, inductance, L _Lo1The other end connect the grid of NMOS pipe M1 and NMOS pipe M4, inductance, L _Lo2The other end connect the grid of NMOS pipe M2 and NMOS pipe M3, the other end of biasing resistor R1 is connected with the other end interconnection of biasing resistor R2 and with bias voltage VG, the output of active Ba Lun is exported intermediate-freuqncy signal.

Compared with prior art, the present invention has following advantage:

1) medium-frequency band is wide.

2) conversion loss is little.

3) isolation height.

Description of drawings

Fig. 1 is passive frequency mixer schematic diagram of the present invention;

Fig. 2 is the model analysis of common grid nmos pass transistor;

Fig. 3 is the simulation curve that passive frequency mixer conversion loss of the present invention changes with intermediate frequency;

Fig. 4 is each interport isolation simulation curve of passive frequency mixer of the present invention.

Embodiment

Referring to Fig. 1, passive frequency mixer of the present invention comprises four mixing NMOS pipes M1, M2, M3, M4, rf inputs Marchand Ba Lun 1, a local oscillator input Marchand Ba Lun 2, four inductance L _Rf1, L _Rf2, L _Lo1, L _Lo2, two capacitance C1, C2, two biasing resistor R1, R2 and an active Ba Lun; Four mixing NMOS pipes are interconnected to the difference balance to pipe, that is: the drain electrode of M1 links to each other with the drain electrode of M3, and the drain electrode of M2 links to each other with the drain electrode of M4; The grid of M1 links to each other with the grid of M4, and the grid of M2 links to each other with the grid of M3; The source electrode of M1 links to each other with the source electrode of M2, and the source electrode of M3 links to each other with the source electrode of M4.Radiofrequency signal is converted into a pair of differential signal by the balance end input of Marchand Ba Lun 1 at non-equilibrium end.2 branch roads of the non-equilibrium end of Marchand Ba Lun 1 have identical connected mode: an end ground connection, the differential signal of other end output is through inductance L _Rf1And L _Rf2Be injected into the source electrode of M1, M2 and M3, M4 respectively.Local oscillation signal is converted into a pair of differential signal by the balance end input of Marchand Ba Lun 2 at non-equilibrium end.2 branch roads of the non-equilibrium end of Marchand Ba Lun 2 have identical connected mode: an end ground connection, the differential signal of other end output is through inductance L _Lo1, capacitance C1 series network and inductance L _Lo2, capacitance C2 series network be injected into the grid of M1, M4 and M2, M4 respectively.One of biasing resistor R1 terminates at L _Lo1, the C1 series network intermediate node; One of biasing resistor R2 terminates at L _Lo2, the C2 series network intermediate node.R1 connects with R2, and series connection node is as the input of bias voltage VG.The drain electrode of the drain electrode of M1, M3 and M2, M4 links to each other with two inputs of active Ba Lun respectively, and intermediate-freuqncy signal is by the output output of active Ba Lun.

Radiofrequency signal is injected mixing transistor by the coupling inductance after Marchand Ba Lun 1 becomes differential signal source electrode utilizes the non-equilibrium branch road one end ground connection of Marchand Ba Lun 1 to provide the loop for radiofrequency signal again dexterously.Local oscillation signal injects the grid of mixing transistor and the radiofrequency signal mixing that source electrode injects by peaking inductance after Marchand Ba Lun 2 becomes differential signal, the non-equilibrium branch road one end ground connection of Marchand Ba Lun 2 provides the loop for local oscillation signal.Intermediate-freuqncy signal is by mixing transistor drain electrode output after active Ba Lun is synthetic.

By 2 Marchand Ba Lun of structural design of the two balanced passive mixers of wide intermediate frequency shown in Figure 1,2 radio-frequency head coupling inductance L _Rf1And L _Rf2, 2 local oscillator end peaking inductance L _Lo1And L _Lo2And active Ba Lun, the while configures the size of mixing transistor simultaneously, presses the total grid width 12 μ m of the long 90nm of grid, single finger widths 3 μ m configuration.

From Fig. 1, take out any one nmos pass transistor, as shown in Figure 2, analyze its operation principle, can release by contrast and adopt source electrode input inductance and grid peaking inductance in the effect aspect radio-frequency (RF) match, reduction conversion loss and lifting bandwidth and the isolation.As seen from Figure 2, the essence of this circuit is a common gate structure of importing from source electrode.Provide earlier below and work as L _Rf=L _Lo=0 o'clock the basic abcd matrix of grid nmos pass transistor altogether.

$\left[\begin{array}{cc}A& B\\ C& D\end{array}\right]=\left[\begin{array}{cc}\frac{{\mathrm{sC}}_{\mathrm{gd}}}{g_m}& \frac{1}{g_m}\\ {\mathrm{sC}}_{\mathrm{gs}}(A+\frac{C_{\mathrm{gd}}}{C_{\mathrm{gs}}})& 1+{\mathrm{BsC}}_{\mathrm{gs}}\end{array}\right]---\left(1\right)$

A, B, C, C are respectively the matrix factor in the formula (1), and s is complex factor, C _GdBe gate leakage capacitance, C _GsBe grid source electric capacity, g _mMutual conductance for the NMOS pipe.

Further consider L _Rf, L _Lo≠ 0 o'clock situation.According to annexation shown in Figure 2, can release the forward voltage gain A of circuit ' be:

$A^{\&prime;}=\frac{U_1}{{\mathrm{<figure-callout\; id="2"\; label="U"\; filenames="130724151115.png"\; state="\{\{state\}\}">U</figure-callout>}}_2}{|}_{{\mathrm{<figure-callout\; id="2"\; label="I"\; filenames="130724151115.png"\; state="\{\{state\}\}">I</figure-callout>}}_{2=0}}=\frac{A+({\mathrm{AC}}_{\mathrm{gs}}+C_{\mathrm{gd}})s^2{L}_{\mathrm{lo}}}{1+({\mathrm{AC}}_{\mathrm{gs}}+C_{\mathrm{gd}})s^2{L}_{\mathrm{lo}}}+\frac{C}{1+({\mathrm{AC}}_{\mathrm{gs}}+C_{\mathrm{gd}})s^2{L}_{\mathrm{lo}}}{\mathrm{sL}}_{\mathrm{rf}}---\left(2\right)$

The reverse voltage gain that the A in the formula (1), C substitution formula (2) can be got circuit shown in Figure 2 is:

$G\left(\mathrm{j\&omega;}\right)=\frac{1}{A^{\&prime;}}=\frac{1}{A}\&times;\frac{1-{\mathrm{\&omega;}}^2{L}_{\mathrm{lo}}{C}_{\mathrm{gd}}-{\mathrm{j\&omega;}}^3{L}_{\mathrm{lo}}{\mathrm{<figure-callout\; id="2"\; label="C\; gd"\; filenames="130724151115.png"\; state="\{\{state\}\}">C</figure-callout>}}_{\mathrm{gd}}^{}}{1-{\mathrm{\&omega;}}^2{C}_{\mathrm{gs}}(L_{\mathrm{lo}}+L_{\mathrm{rf}})+{\mathrm{j\&omega;g}}_m{C}_{\mathrm{gd}}(L_{\mathrm{lo}}+L_{\mathrm{rf}})}---\left(3\right)$

Wherein ω is angular frequency.The amplitude that can be got voltage gain by formula (3) is:

$G\left(\mathrm{\&omega;}\right)=\frac{1}{\left|A^{\&prime;}\right|}=\frac{1}{\left|A\right|}\&times;\frac{\sqrt{{(1-{\mathrm{\&omega;}}^2{L}_{\mathrm{lo}}{C}_{\mathrm{gd}})}^2+{\left({\mathrm{\&omega;}}^3{L}_{\mathrm{lo}}{C}_{\mathrm{gd}}^2\right)}^2}}{\sqrt{{[1-{\mathrm{\&omega;}}^2{C}_{\mathrm{gs}}(L_{\mathrm{lo}}+L_{\mathrm{rf}})]}^2+{\left[\mathrm{\&omega;}{g}_m{C}_{\mathrm{gd}}(L_{\mathrm{lo}}+L_{\mathrm{rf}})\right]}^2}}---\left(4\right)$

1/|A| is L in the formula (4) _Rf=L _LoBe total to the amplitude of the reverse voltage gain of grid nmos pass transistor at=0 o'clock.Clearly, the numerical value of the fraction on multiplication sign the right increases with the frequency increase, and this produces the effect of offsetting to 1/|A| with the trend that frequency increase numerical value reduces, and this means that bandwidth has been expanded under the identical gain.Therefore, increasing grid peaking inductance L _LoAfter, intermediate-frequency bandwidth is expanded.Can also release maximum gain G by formula (4) in addition _Max1/|A|.Therefore, grid peaking inductance L _LoIntroducing promoted maximum gain.If 1-ω in the formula (4) ²C _Gs(L ₁+ L ₂)=0 item has formed the matching condition of circuit, so L _RfAnd L _LoIntroducing be conducive to the coupling of rf inputs.At last, because radiofrequency signal is injected from source electrode, local oscillation signal injects from grid, so L _RfAnd L _LoExistence can promote the isolation of radio frequency-intermediate frequency and local oscillator-intermediate frequency.

Two coupling inductance L _Rf1And L _Rf2Be connected to the input radio frequency signal with the non-equilibrium branch road of Marchand Ba Lun 1 loop is provided, not only promoted the input matching performance but also promoted mixing efficiency; Two peaking inductance L _Lo1And L _Lo2Being connected to the input local oscillation signal with the non-equilibrium branch road of Marchand Ba Lun 2 provides the loop further to promote mixing efficiency.Finally, as shown in Figure 3, the conversion loss of frequency mixer was fluctuateed up and down at 4dB when local oscillation power was 0dBm, the intermediate-frequency bandwidth (f of corresponding 1～14GHz _LO=27GHz refers to the simulated conditions local frequency at 27GHz, f _LO=33GHz refers to the simulated conditions local frequency at 33GHz, P _LO=0dBm simulated conditions local oscillation power is at 0dBm).Each interport isolation shown in Figure 4 when local frequency is 33GHz all greater than 40dB(f _LO=33GHz refers to that the simulated conditions local frequency is at 33GHz).

Claims (1)

1. the two balanced passive mixers of the millimeter wave of a wide intermediate frequency is characterized in that: comprise four mixing NMOS pipes M1, M2, M3, M4, rf inputs Marchand Ba Lun, a local oscillator input Marchand Ba Lun, four inductance L _Rf1, L _Rf2, L _Lo1, L _Lo2, two capacitance C1, C2, two biasing resistor R1, R2 and an active Ba Lun; Radiofrequency signal is converted into a pair of differential signal at non-equilibrium end and is passed through inductance respectively by the balance end input of rf inputs Marchand Ba Lun L _Rf1With L _Rf2Connect the source electrode of NMOS pipe M1, M2 and the source electrode of NMOS pipe M3, M4, the drain electrode of NMOS pipe M1 connects the drain electrode of NMOS pipe M3 and is connected with the input of active Ba Lun, the drain electrode of NMOS pipe M2 connects the drain electrode of NMOS pipe M4 and is connected with another input of active Ba Lun, local oscillation signal is converted into a pair of differential signal at non-equilibrium end and is connected biasing resistor R1 and inductance with C2 through capacitance C1 respectively by the balance end input of local oscillator input Marchand Ba Lun _, L _Lo1An end and biasing resistor R2 and inductance _, L _Lo2An end, inductance _, L _Lo1The other end connect the grid of NMOS pipe M1 and NMOS pipe M4, inductance _, L _Lo2The other end connect the grid of NMOS pipe M2 and NMOS pipe M3, the other end of biasing resistor R1 is connected with the other end interconnection of biasing resistor R2 and with bias voltage VG, the output of active Ba Lun is exported intermediate-freuqncy signal.

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