CN1697311A - Mixer made from MOS field effect transistor in low voltage and low power consumption - Google Patents

Abstract

The mixer includes metal oxide semiconductor field effect transistor (MOSFET) parts, resistances, inductances and capacitances. MOSFET includes one or more dual-gate field effect transistors (FET). Radio frequency signal and signal of local oscillation are applied to front gate / back gate of dual-gate FET. Certain offset voltage is added to MOSFET part in order to guarantee the part operates at saturation region. Load is resistances, inductances and capacitances or any combination among them. Since radio frequency signal and signal of local oscillation are input at same time, mixed under low voltage. In favor of operation at low voltage and low power consumption, the invention is applicable to deep sub micro RF CMOS circuit.

Description

The made from MOS field effect transistor in low voltage and low power consumption frequency mixer

Technical field

The invention belongs to the low-voltage and low-power dissipation CMOS RFIC applied technical field in deep-submicron epoch, the low-voltage and low-power dissipation frequency mixer (Mixer) in especially a kind of radio-frequency (RF) CMOS integrated circuit (RFIC).

Background technology

Along with the cmos vlsi technology entered for 65 eras of nanotechnology, serious short-channel effect (short channel effect) appears in the field-effect transistor in the circuit, showing as threshold voltage (threshold voltage) reduces with channel length and descends, threshold voltage increases with drain terminal voltage and descends, and the device intrinsic output resistance reduction that the long mudulation effect of direct break-through (punch-through) ditch causes etc. is leaked in the source.The second-order effects of the caused device of short-channel effect causes circuit malfunction easily.Therefore the inhibition of short-channel effect is the urgent problem that improves the cmos vlsi circuit performance and reduce circuit malfunction.

At present, in order to suppress short-channel effect, the general employing improved the tagma doping content, introduces the pocket structure at channel region, and light dope expansion area methods such as (light doped source/drain extension) is leaked in the increase source.Yet these technological means all can't fundamentally be eliminated short channel effect, especially after integrated circuit technique enters nanometer era, the ditch of device is long near the physics limit of body silicon CMOS, therefore the above-mentioned technological means device operational failure that nearly all can't avoid short channel effect to cause.

The current research personnel generally believe that double-gated devices (Double Gate or Dual Gate) is that the device grid reach the effective way that solves body silicon device short channel effect after 10 nanometers.Part Study personnel also predict because the low-power consumption feature of device itself, double-gated devices more morning be applied to such as mobile phone etc. need low pressure, low-power consumption, small size, cheaply in the mobile device.According to different preparation process and device architecture, double-gated devices can be divided into planar double-gated (Planar DG), FinFET and vertical double gate (Vertical DG).

The operating voltage of device also constantly reduces thereupon in device dimensions shrink, therefore requires supply voltage in the circuit must not surpass the maximum working voltage of device.Therefore in the radio circuit design process, should reduce supply voltage as much as possible to satisfy the job requirement of device.

Frequency mixer is that requisite one of institute forms module in the modern radio-frequency communication, and what current main receiver adopted mostly is class gilbert type frequency mixer.The structure of gilbert mixer as shown in Figure 1, current source I wherein _BiasFor entire circuit produces bias current, realize (also can omit) by metal-oxide-semiconductor usually in the practical application; Common source pipe M1, M2 have constituted transconductance stage, convert the difference radio-frequency signal of voltage form of input to current signal and it is amplified; The local oscillation signal of difference then is input to four grid ends of the switching stage of being made up of jointly M3, M4, M5, M6 respectively.By local oscillation signal the modulation of transconductance stage output current is realized mixing operation, and convert current signal to voltage signal output by load.For desirable switching stage, the conversion gain of whole frequency mixer is

G wherein _mBe the transconductance value of transconductance stage, R _LBe the load resistance value.But because the realization of whole frequency mixer needs to adopt the stacking of two-stage metal-oxide-semiconductor at least, so limited the minimum value of whole supply voltage.Therefore this structure has been difficult to be applied to the designing requirement that low pressure, low-power consumption and deep submicron process supply voltage constantly reduce again.Also can adopt foldable structure in order to reduce supply voltage, but the power consumption of circuit can increase thereupon also, this is fatal to mobile communication.Often need between conversion gain, the linearity, noise factor and power consumption parameter, compromise as frequency mixer simultaneously, further increase requirement power consumption and supply voltage.

As the simplest square of rule frequency mixer (Square-Law Mixer) structure is to utilize the quadratic nonlinearity of desirable MOS device to realize the mixing operation of two incoming frequencies.Its concrete structure is added in RF and LO signal simultaneously at the grid end of MOS device and adds that certain bias voltage is operated in the saturation region to guarantee device as shown in Figure 2, and the combination in any between resistance, inductance, electric capacity or the three is adopted in its load.Drain terminal at the MOS device can produce required mixing results like this.Though the frequency mixer of this structure is very simple, and have very low operating voltage and a lower power consumption, but because radiofrequency signal and local oscillation signal be simultaneously from the grid end input of MOS device, therefore the non-constant that becomes of the isolation between the two makes this structure to be applied in the middle of the reality.

Summary of the invention

The invention provides a kind of low-voltage and low-power dissipation double grids MOSFET frequency mixer, realized low-voltage and low-power consumption, can be used for the application of deep-submicron RF cmos circuit.

Technology contents of the present invention: a kind of made from MOS field effect transistor in low voltage and low power consumption frequency mixer, comprise mos field effect transistor MOSFET device, resistance, inductance, electric capacity, radiofrequency signal and local oscillation signal are added on the MOSFET device simultaneously, and add that certain bias voltage is operated in the saturation region to guarantee device, resistance is adopted in its load, inductance, combination in any between electric capacity or the three, the MOSFET device is one or several dual gate FETs, from the preceding grid/back of the body grid input of above-mentioned dual gate FET, respectively from the back of the body grid/preceding grid of above-mentioned dual gate FET import respectively by local oscillation signal for radiofrequency signal.

The MOSFET device can be two dual gate FETs 1 and 2, positive radiofrequency signal is from the preceding grid input of dual gate FET 1, positive local oscillation signal is from dual gate FET 1 back of the body grid input, negative radiofrequency signal is from the preceding grid input of dual gate FET 2, and negative local oscillation signal is from the back of the body grid input of dual gate FET 2.Or positive radiofrequency signal is from the back of the body grid input of dual gate FET 1, positive local oscillation signal is from dual gate FET 1 preceding grid input, negative radiofrequency signal is from the back of the body grid input of dual gate FET 2, and negative local oscillation signal is from the preceding grid input of dual gate FET 2.

The MOSFET device is four dual gate FETs 1,2,3 and 4, positive radiofrequency signal is imported from the preceding grid of dual gate FET 1 and dual gate FET 2 respectively, positive local oscillation signal is imported from the back of the body grid of dual gate FET 1 and dual gate FET 4 respectively, from the preceding grid input of dual gate FET 3 and dual gate FET 4, respectively from the back of the body grid of dual gate FET 2 and dual gate FET 3 import respectively by negative local oscillation signal for negative radiofrequency signal.Or another mode: positive radiofrequency signal is imported from the back of the body grid of dual gate FET 1 and dual gate FET 2 respectively, positive local oscillation signal is imported from the preceding grid of dual gate FET 1 and dual gate FET 4 respectively, from the back of the body grid input of dual gate FET 3 and dual gate FET 4, respectively from the back of the body grid of dual gate FET 2 and dual gate FET 3 import respectively by negative local oscillation signal for negative radiofrequency signal.

Mixer output can be provided with electric capacity, is used for high fdrequency component in the filtering output.

Add current source with the stabilizing circuit electric current at the source of dual gate FET device end.Described current source is by the combination in any between MOSFET device, resistance, inductance, the electric capacity or four.

Technique effect of the present invention: the present invention adopts the dual-gate MOS tube device, the input of local oscillation signal and the input of radiofrequency signal are respectively the preceding grid or the back of the body grid of dual gate FET, in same MOS device, realize importing in local oscillation signal and the radiofrequency signal, avoided adopting the mode of stacking that frequency mixer is divided into transconductance stage and switching stage is realized mixing in two steps, therefore can save the used up drain-source voltage of switching stage in gilbert's transistor npn npn (or transconductance stage) at least after adopting this structure, thereby comparing the voltage remaining that can reduce at least with conventional mixer is a drain-source voltage value, makes the needed minimum operating voltage of frequency mixer can be lower than 1V.Because this structure has realized low-voltage and low-power consumption simultaneously, is very suitable for the application of deep-submicron RF cmos circuit.

Description of drawings

Below in conjunction with accompanying drawing, the present invention is made detailed description.

The two balance double grid frequency mixer schematic diagrames of Fig. 1 class gilbert type;

Fig. 2 square of rule frequency mixer (Square-Law Mixer) structural representation;

Fig. 3 double-gated devices structural representation;

The mixer architecture schematic diagram that Fig. 4 the present invention constitutes with a double grids MOSFET device;

The mixer architecture schematic diagram that Fig. 5 the present invention constitutes with two double grids MOSFET devices;

The two balance double grid frequency mixer schematic diagrames of Fig. 6 class gilbert's type of the present invention.

Embodiment

The present invention has adopted novel double grids MOSFET device architecture to reduce the operating voltage of frequency mixer, and the concrete structure of double grids MOSFET device as shown in Figure 3.Two discrete grid of double-gated devices are brought in the mixing that realizes between radiofrequency signal and the local oscillation signal as the input of two signals respectively, thereby have avoided influencing each other between tradition square two input signals of rule type frequency mixer.

The frequency mixer that the present invention constitutes with a double grids MOSFET device, its concrete structure as shown in Figure 4.Wherein RF and LO signal are imported from the preceding grid and the back of the body grid of double-gated devices respectively, simultaneously two grid are applied certain bias voltage and be operated in the saturation region to guarantee device, the load of double-gated devices can be adopted the combination in any between resistance, inductance, electric capacity or the three, can obtain required mixing results at the drain terminal of MOSFET.

The operation principle of this mixer architecture can be explained as follows:

One, the mixing between LO signal and the RF signal mainly is the non-linear realization that utilizes the MOS device.General common non linear system can adopt following formula to represent:

y(t)＝α ₁x(t)+α ₂x ²(t)+α ₃x ³(t)+......+α _nx ⁿ(t)

Wherein x (t) represents input signal, and y (t) expression output signal is as RF signal (V _RF(t)=A ₁(t) COS (ω _RFAnd LO (V t)) _LO(t)=A ₂(t) COS (ω _LOT)) signal passes through after the non linear system simultaneously, two signal multiplication items wherein will inevitably occur $V_{\mathrm{IF}}\left(t\right)=\frac{A_1\left(t\right)A_2\left(t\right)}{2}[\mathrm{COS}({\mathrm{\ω}}_{\mathrm{RF}}-{\mathrm{\ω}}_{\mathrm{LO}})t+\mathrm{COS}({\mathrm{\ω}}_{\mathrm{RF}}+{\mathrm{\ω}}_{\mathrm{LO}})t],$ Common ω wherein _RF-ω _LOBe final intermediate frequency (IF) mixing results.

Two, the structure of establishing double-gated devices as shown in Figure 3, then leakage current and two the alive passes of grid for asymmetric double grid are:

I _dz＝I _drift+I _diff (1)

Drift current I wherein _DriftWith dissufion current I _DiffExpression formula be respectively

$I_{\mathrm{drift}}=\frac{W}{L}{\mathrm{\μ}}_n\frac{Q_{\mathrm{FS}}^2-Q_{\mathrm{FD}}^2}{2(C_{\mathrm{oxf}}^{\′}+C_{\mathrm{si}}^{\′})}+\frac{W}{L}{\mathrm{\μ}}_n\frac{Q_{\mathrm{BS}}^2-Q_{\mathrm{BD}}^2}{2(C_{\mathrm{oxb}}^{\′}+C_{\mathrm{si}}^{\′})}$

$I_{\mathrm{diff}}=\frac{W}{L}{\mathrm{\μ}}_n{U}_T(Q_{\mathrm{FD}}-Q_{\mathrm{FS}})+\frac{W}{L}{\mathrm{\μ}}_n{U}_T(Q_{\mathrm{BD}}-Q_{\mathrm{BS}})---\left(2\right)$

Preceding grid can be represented by the formula with back of the body grid unit are inversion layer charge density

Q′ _Finv＝-C′ _oxf(V _FG-V _fbf-V _TFG+κ ₁V _BG-κ ₁V _S-V _ch(x))

Q′ _Binv＝-C′ _oxb(V _BG-V _fbb-V _TBG+κ ₂V _FG-κ ₂V _S-V _ch(x)) (3)

In the formula (2) (3) $U_T=\frac{\mathrm{KT}}{q},$ $C_{\mathrm{oxf}}^{\′}=\frac{{\mathrm{\ϵ}}_{\mathrm{ox}}}{t_{\mathrm{oxf}}},$ $C_{\mathrm{oxb}}^{\′}=\frac{{\mathrm{\ϵ}}_{\mathrm{ox}}}{t_{\mathrm{oxb}}}$ Grid and the grid oxygen electric capacity of carrying on the back grid before representing respectively, $C_{\mathrm{Si}}^{\′}=\frac{{\mathrm{\ϵ}}_{\mathrm{Si}}}{t_{\mathrm{Si}}}$ Expression channel body Si electric capacity, ${\mathrm{\κ}}_1=\frac{C^{\′}}{{C^{\′}}_{\mathrm{oxf}}},$ ${\mathrm{\κ}}_2=\frac{C^{\′}}{{C^{\′}}_{\mathrm{oxb}}},$ V _Ch=φ _n-Φ _FThe expression groove potential.Q _FS=Q ' _Finv(0), Q _FD=Q ' _Finv(L), Q _BS=Q ' _Binv(0), Q _BD=Q ' _Binv(L); Substitution formula (3) can get

Q _FS＝-C’ _oxf(V _FG-V _fbf-V _TFG+κ ₁V _BG-κ ₁V _S-V _Ch(0))

Q _FD＝-C’ _oxf(V _FG-V _fbf-V _TFG+κ ₁V _BG-κ ₁V _S-V _Ch(L))

(4)

Q _BS＝-C’ _oxB(V _BG-V _fbb-V _TBG+κ ₂V _FG-κ ₂V _S-V _Ch(0))

Q _BS＝-C’ _oxB(V _BG-V _fbb-V _TBG+κ ₂V _FG-κ ₂V _S-V _Ch(L))

(4) (2) formula substitution formula (1) can be got I _DsExpression formula, I wherein _DriftItem can produce needed mixing item as shown in Equation (5).

$\frac{W}{L}\·\frac{{\mathrm{\μ}}_n\·C_{\mathrm{oxf}}^2}{(C_{\mathrm{oxf}}+C_{\mathrm{si}})}\·{\mathrm{\κ}}_1\·V_{\mathrm{FG}}\·V_{\mathrm{BG}}+\frac{W}{L}\·\frac{{\mathrm{\μ}}_n\·C_{\mathrm{oxf}}^2}{(C_{\mathrm{oxb}}+C_{\mathrm{si}})}\·{\mathrm{\κ}}_2\·V_{\mathrm{FG}}\·V_{\mathrm{BG}}---\left(5\right)$

Two input end signal expression formulas supposing double-gated devices are: V _FG=V _FG0+ V _RFCOS (ω _RFT) and V _BG=V _LO0+ V _LOCOS (ω _LOT); V wherein _FG0And V _LO0The dc offset voltage of representing double-gated devices RF and LO input respectively.With V _FGAnd V _BGThe formula that embodies substitution formula (2) in can obtain I _DriftExpression formula in contain AV _FGV _BGItem (wherein A represents this coefficient)

$I_{\mathrm{drift}}=\·\·\·+{\mathrm{AV}}_{\mathrm{FG}}{V}_{\mathrm{BG}}+\·\·\·=\·\·\·+{\mathrm{AV}}_{\mathrm{RF}}\mathrm{COS}\left({\mathrm{\ω}}_{\mathrm{RF}}t\right)V_{\mathrm{LO}}\mathrm{COS}\left({\mathrm{\ω}}_{\mathrm{LO}}t\right)+\·\·\·$

$=\·\·\·+\frac{A}{2}{V}_{\mathrm{RF}}{V}_{\mathrm{LO}}[\mathrm{COS}({\mathrm{\ω}}_{\mathrm{LO}}-{\mathrm{\ω}}_{\mathrm{RF}})t+\mathrm{COS}({\mathrm{\ω}}_{\mathrm{LO}}+{\mathrm{\ω}}_{\mathrm{RF}})t]+\·\·\·---\left(6\right)$

Formula (6) clearly shows by double-gated devices can produce new frequency component ω _RF± ω _LO(up-conversion and down-converted component represented respectively in plus sige and minus sign), thus realized the mixing function.

The two balance double grid frequency mixers of class gilbert's type of the present invention, promptly with the frequency mixer of four double grids MOSFET devices formations, concrete structure as shown in Figure 5.As can be seen from Figure 5, this structure MOSFET device can be two dual gate FETs 1 and 2, positive radiofrequency signal is from the preceding grid input of dual gate FET 1, positive local oscillation signal is from dual gate FET 1 back of the body grid input, negative radiofrequency signal is from the preceding grid input of dual gate FET 2, and negative local oscillation signal is from the back of the body grid input of dual gate FET 2.Or another mode: positive radiofrequency signal is from the back of the body grid input of dual gate FET 1, positive local oscillation signal is from dual gate FET 1 preceding grid input, negative radiofrequency signal is from the back of the body grid input of dual gate FET 2, and negative local oscillation signal is from the preceding grid input of dual gate FET 2.

The two balance double grid frequency mixers of class gilbert's type of the present invention, promptly with the frequency mixer of four double grids MOSFET devices formations, concrete structure as shown in Figure 6.As can be seen from Figure 6, this structure adopts difference radio-frequency signal and local oscillation signal input.Wherein positive radiofrequency signal 7 inputs are connected with the preceding grid of dual gate FET 1, dual gate FET 2, and negative radiofrequency signal 8 inputs are connected with the preceding grid of dual gate FET 3, dual gate FET 4; Positive local oscillation signal 5 inputs are connected with the back of the body grid of dual gate FET 1, dual gate FET 4, and negative local oscillation signal 6 inputs are connected with the back of the body grid of dual gate FET 2, dual gate FET 3; Electric capacity 9 is used for the high fdrequency component in the filtering output 10,11; Resistance 12,13 is load, also can adopt the active load that is made of as load or MOS device etc. inductance, electric capacity.Add current source with the stabilizing circuit electric current at the source of dual gate FET device end, current source is by the combination in any between MOSFET device, resistance, inductance, the electric capacity or four.Therefore because input when in same MOS device, having realized local oscillation signal and radiofrequency signal, avoided adopting the mode of stacking that frequency mixer is divided into transconductance stage and switching stage is realized mixing in two steps.Its advantage is: even number time strange change that 1, can further reduce frequency mixer; 2, increased isolation between local oscillation signal (LO) and the intermediate-freuqncy signal; 3, also having been cancelled out each other owing to RF and LO signal from mixing the DC amount that produces.

The present invention can save the used up drain-source voltage of switching stage in gilbert's transistor npn npn (or transconductance stage) after adopting this structure at least, thereby comparing the voltage remaining that can reduce at least with conventional mixer is a drain-source value, makes the needed minimum operating voltage of frequency mixer can be lower than 1V.Because this structure has realized low-voltage and low-power consumption simultaneously, makes it be very suitable for the application of deep-submicron RF cmos circuit.

Claims (6)

1, a kind of made from MOS field effect transistor in low voltage and low power consumption frequency mixer, comprise mos field effect transistor MOSFET device, resistance, inductance, electric capacity, radiofrequency signal and local oscillation signal are added on the MOSFET device simultaneously, and add that certain bias voltage is operated in the saturation region to guarantee device, resistance is adopted in its load, inductance, combination in any between electric capacity or the three, it is characterized in that: the MOSFET device is one or several dual gate FETs, from the preceding grid/back of the body grid input of above-mentioned dual gate FET, respectively from the back of the body grid/preceding grid of above-mentioned dual gate FET import respectively by local oscillation signal for radiofrequency signal.

2, made from MOS field effect transistor in low voltage and low power consumption frequency mixer as claimed in claim 1, it is characterized in that: the MOSFET device is two dual gate FETs 1 and 2, positive radiofrequency signal is from the preceding grid/back of the body grid input of dual gate FET 1, positive local oscillation signal is from dual gate FET 1 back of the body grid/preceding grid input, negative radiofrequency signal is from the preceding grid/back of the body grid input of dual gate FET 2, and negative local oscillation signal is from the back of the body grid/preceding grid input of dual gate FET 2.

3, made from MOS field effect transistor in low voltage and low power consumption frequency mixer as claimed in claim 1, it is characterized in that: the MOSFET device is four dual gate FETs 1,2,3 and 4, positive radiofrequency signal is imported from the preceding grid/back of the body grid of dual gate FET 1 and dual gate FET 2 respectively, positive local oscillation signal is imported from the back of the body grid/preceding grid of dual gate FET 1 and dual gate FET 4 respectively, from the preceding grid/back of the body grid input of dual gate FET 3 and dual gate FET 4, respectively from the back of the body grid/preceding grid of dual gate FET 2 and dual gate FET 3 import respectively by negative local oscillation signal for negative radiofrequency signal.

4, as claim 1,2 or 3 described made from MOS field effect transistor in low voltage and low power consumption frequency mixers, it is characterized in that: the output of frequency mixer is provided with electric capacity, is used for high fdrequency component in the filtering output.

5, as claim 1,2 or 3 described made from MOS field effect transistor in low voltage and low power consumption frequency mixers, it is characterized in that: add current source with the stabilizing circuit electric current at the source of described dual gate FET device end.

6, made from MOS field effect transistor in low voltage and low power consumption frequency mixer as claimed in claim 5 is characterized in that: described current source is by the combination in any between MOSFET device, resistance, inductance, the electric capacity or four.

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