CN1697311A - Low Voltage Low Power Dual Gate MOSFET Mixer - 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

Low Voltage Low Power Dual Gate MOSFET Mixer

technical field

The invention belongs to the field of low-voltage and low-power CMOS RFIC application technology in the deep submicron era, in particular to a low-voltage and low-power mixer (Mixer) in a radio frequency CMOS integrated circuit (RFIC).

Background technique

As CMOS VLSI technology enters the era of 65nm technology, the field effect transistor in the circuit has a serious short channel effect, which is manifested as the threshold voltage (threshold voltage) decreases with the decrease of the channel length. The threshold voltage decreases with the increase of the drain terminal voltage, and the intrinsic output resistance of the device is reduced due to the direct source-drain punch-through (punch-through) channel length modulation effect. The second-order effect of the device caused by the short channel effect is easy to cause circuit failure. Therefore, the suppression of short-channel effects is an urgent problem to be solved to improve the performance of CMOS VLSI circuits and reduce circuit failure.

At present, in order to suppress the short channel effect, methods such as increasing the doping concentration of the body region, introducing a pocket structure in the channel region, and increasing the light doped source/drain extension of the source and drain are generally adopted. However, none of these technical means can fundamentally eliminate the short-channel effect, especially when integrated circuit technology enters the nanometer era, the channel length of the device is close to the physical limit of bulk silicon CMOS, so the above-mentioned technical means can hardly avoid the short-channel effect cause device failure.

At present, researchers generally believe that double gate devices (Double Gate or Dual Gate) are the most effective way to solve the short channel effect of bulk silicon devices after the device gate length reaches 10 nanometers. Some researchers also predict that due to the low power consumption characteristics of the device itself, dual-gate devices will be used earlier in mobile devices that require low voltage, low power consumption, small size, and low cost, such as mobile phones. According to different preparation processes and device structures, dual-gate devices can be divided into planar double-gate (Planar DG), FinFET and vertical double-gate (Vertical DG).

As the size of the device shrinks, the operating voltage of the device is also continuously reduced. Therefore, it is required that the power supply voltage in the circuit must not exceed the maximum operating voltage of the device. Therefore, the power supply voltage should be reduced as much as possible in the design process of the radio frequency circuit to meet the working requirements of the device.

其中G_m为跨导级的跨导值，R_L为负载电阻值。但是由于整个混频器的实现至少需要采用两级MOS管的堆垛，所以限制了整个电源电压的最小值。因此这种结构已经很难再应用于低压、低功耗和深亚微米工艺电源电压不断降低的设计要求。为了降低电源电压也可以采用折叠结构，但是电路的功耗也会随之而增加，这对移动通讯来说是致命的。同时作为混频器而言经常需要在转换增益、线性度、噪声系数和功耗参数之间进行折中，进一步增加了对功耗和电源电压的要求。The mixer is an indispensable component in modern radio frequency communication, and most of the current main receivers use Gilbert-like mixers. The structure of the Gilbert mixer is shown in Figure 1, in which the current source I _Bias generates a bias current for the entire circuit, which is usually implemented by a MOS tube in practical applications (it can also be omitted); the common source tubes M1 and M2 constitute The transconductance stage converts the input differential RF signal in the form of voltage into a current signal and amplifies it; the differential local oscillator signal is respectively input to the four gate terminals of the switch stage composed of M3, M4, M5, and M6 . The frequency mixing operation is realized by modulating the output current of the transconductance stage by the local oscillator signal, and the current signal is converted into a voltage signal for output through the load. For an ideal switching stage, the conversion gain of the overall mixer is

Among them, G _m is the transconductance value of the transconductance stage, and _RL is the load resistance value. However, since the realization of the entire mixer requires at least two stages of stacking of MOS transistors, the minimum value of the entire power supply voltage is limited. Therefore, this structure has been difficult to apply to the design requirements of low voltage, low power consumption, and deep submicron process power supply voltage. In order to reduce the power supply voltage, a folding structure can also be adopted, but the power consumption of the circuit will also increase accordingly, which is fatal to mobile communications. At the same time, as a mixer, it is often necessary to compromise among conversion gain, linearity, noise figure and power consumption parameters, which further increases the requirements on power consumption and power supply voltage.

As the simplest square-law mixer (Square-Law Mixer) structure, the square nonlinearity of the ideal MOS device is used to realize the mixing operation of two input frequencies. Its specific structure is shown in Figure 2. The RF and LO signals are simultaneously applied to the gate terminal of the MOS device and a certain bias voltage is added to ensure that the device works in the saturation region. The load adopts resistance, inductance, capacitance or all three any combination in between. In this way, the desired mixing result can be generated at the drain end of the MOS device. Although the mixer with this structure is very simple, and has very low operating voltage and low power consumption, since the radio frequency signal and the local oscillator signal are input from the gate terminal of the MOS device at the same time, the isolation between the two becomes very poor, thus making this structure unusable in practice.

Contents of the invention

The invention provides a double-gate MOSFET mixer with low voltage and low power consumption, which realizes low voltage and low power consumption, and can be used in the application of deep submicron RF CMOS circuits.

Technical content of the present invention: a low-voltage low-power dual-gate metal-oxide-semiconductor field-effect transistor mixer, including a metal-oxide-semiconductor field-effect transistor MOSFET device, a resistor, an inductor, and a capacitor, and simultaneously transmits a radio frequency signal and a local oscillator signal Applied to the MOSFET device, and a certain bias voltage is added to ensure that the device works in the saturation region. The load adopts resistance, inductance, capacitance or any combination of the three. The MOSFET device is one or several double gate fields For the effect transistor, the radio frequency signal is respectively input from the front gate/back gate of the double gate field effect transistor, and the local oscillation signal is respectively input from the back gate/front gate of the above double gate field effect transistor.

The MOSFET device can be two double gate field effect transistors 1 and 2, the positive radio frequency signal is input from the front gate of the double gate field effect transistor 1, the positive local oscillator signal is input from the back gate of the double gate field effect transistor 1, and the negative radio frequency signal is input from the back gate of the double gate field effect transistor 1. The signal is input from the front gate of the double gate field effect transistor 2, and the negative local oscillation signal is input from the back gate of the double gate field effect transistor 2. Or the positive RF signal is input from the back gate of the double gate field effect transistor 1, the positive local oscillator signal is input from the front gate of the double gate field effect transistor 1, the negative radio frequency signal is input from the back gate of the double gate field effect transistor 2, and the negative radio frequency signal is input from the back gate of the double gate field effect transistor 2. The local oscillator signal is input from the front gate of the double gate field effect transistor 2 .

The MOSFET devices are four dual-gate field effect transistors 1, 2, 3 and 4, the positive radio frequency signals are respectively input from the front gates of dual-gate field-effect transistor 1 and dual-gate field-effect transistor 2, and the positive local oscillator signals are respectively input from the dual-gate field-effect transistors The back gate input of gate field effect transistor 1 and double gate field effect transistor 4, the negative radio frequency signal is input from the front gate of double gate field effect transistor 3 and double gate field effect transistor 4 respectively, and the negative local oscillation signal is respectively input from the double gate field effect transistor Back gate input of field effect transistor 2 and double gate field effect transistor 3. Or another way: the positive radio frequency signal is input from the back gate of the double gate field effect transistor 1 and the double gate field effect transistor 2 respectively, and the positive local oscillator signal is respectively input from the double gate field effect transistor 1 and the double gate field effect transistor 4 The negative radio frequency signal is input from the back gate of the double gate field effect transistor 3 and the double gate field effect transistor 4 respectively, and the negative local oscillator signal is respectively input from the double gate field effect transistor 2 and the double gate field effect transistor 3 back gate input.

A capacitor may be provided at the output end of the mixer to filter out high-frequency components in the output end.

A current source is added to the source terminal of the dual gate field effect transistor device to stabilize the circuit current. The current source is composed of MOSFET devices, resistors, inductors, capacitors or any combination of the four.

Technical effect of the present invention: the present invention adopts double-gate MOS tube device, and the input terminal of the local oscillator signal and the input terminal of the radio frequency signal are respectively the front gate or the back gate of the double-gate field effect transistor, realizes the local oscillator in the same MOS device Simultaneous input of signals and radio frequency signals avoids the use of stacking to divide the mixer into a transconductance stage and a switch stage to realize frequency mixing in two steps. Therefore, after adopting this structure, at least the switch in the Gilbert-type transistor can be omitted. Stage (or transconductance stage) consumes the drain-source voltage, so compared with the traditional mixer, the voltage margin can be reduced by at least one drain-source voltage value, so that the minimum operating voltage required by the mixer can be lower than 1V. Because the structure realizes low voltage and low power consumption at the same time, it is very suitable for the application of deep submicron RF CMOS circuits.

Description of drawings

The present invention will be described in detail below in conjunction with the accompanying drawings.

Fig. 1 schematic diagram of Gilbert-type double-balanced double-gate mixer;

Fig. 2 Structural schematic diagram of square-law mixer (Square-Law Mixer);

Figure 3 is a schematic diagram of the structure of a double-gate device;

Fig. 4 the present invention constitutes the structural representation of the mixer with a double-gate MOSFET device;

FIG. 5 is a structural schematic diagram of a mixer composed of two dual-gate MOSFET devices in the present invention;

Fig. 6 is a schematic diagram of a Gilbert-like double-balanced double-gate mixer of the present invention.

Detailed ways

The present invention adopts a novel dual-gate MOSFET device structure to reduce the working voltage of the mixer, and the specific structure of the dual-gate MOSFET device is shown in FIG. 3 . The two discrete gates of the dual gate device are used as the input terminals of the two signals to realize the mixing between the radio frequency signal and the local oscillator signal, thus avoiding the mutual influence between the two input signals of the traditional square law mixer .

The specific structure of the mixer composed of a dual-gate MOSFET device in the present invention is shown in FIG. 4 . The RF and LO signals are respectively input from the front gate and back gate of the double gate device, and a certain bias voltage is applied to the two gates at the same time to ensure that the device works in the saturation region. The load of the double gate device can be resistance, inductance, capacitance or It is any combination of the three, and the desired mixing result can be obtained at the drain end of the MOSFET.

The working principle of this mixer structure can be explained as follows:

1. The frequency mixing between the LO signal and the RF signal is mainly realized by using the nonlinearity of the MOS device. A common nonlinear system can be represented by the following formula:

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

where x(t) represents the input signal and y(t) represents the output signal when the RF signal (V _RF (t)=A ₁ (t)COS(ω _RF t)) and LO(V _LO (t)=A ₂ ( t) After the COS(ω _LO t)) signal passes through the nonlinear system at the same time, there must be two signal multiplication items $V_{\mathrm{IF}}\left(t\right)=\frac{A_1\left(t\right)A_2\left(t\right)}{2}[\mathrm{COS}({\mathrm{\ω}}_{\mathrm{RF}}-{\mathrm{\ω}}_{\mathrm{LO}})t+\mathrm{COS}({\mathrm{\ω}}_{\mathrm{RF}}+{\mathrm{\ω}}_{\mathrm{LO}})t],$ Usually ω _RF -ω _LO is the final intermediate frequency (IF) mixing result.

2. Assuming that the structure of the double-gate device is shown in Figure 3, the relationship between the leakage current of the asymmetric double-gate and the voltage applied to the two gates is:

I _dz =I _drift +I _diff (1)

The expressions of the drift current I _drift and the diffusion current I _diff are respectively

${\mathrm{<span\; class="notranslate">\; I</span>}}_{\mathrm{<span\; class="notranslate">\; drift</span>}}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; W</span>}}{\mathrm{<span\; class="notranslate">\; L</span>}}{\mathrm{<span\; class="notranslate">\; \&mu;</span>}}_{\mathrm{<span\; class="notranslate">\; no</span>}}\frac{{\mathrm{<span\; class="notranslate">\; Q</span>}}_{\mathrm{<span\; class="notranslate">\; FS</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="Q\; FD"\; filenames="A20051001192800112.png"\; state="\{\{state\}\}">Q</figure-callout></span><figure-callout\; id="2"\; label="Q\; FD"\; filenames="A20051001192800112.png"\; state="\{\{state\}\}">\; </figure-callout>}}_{\mathrm{<span\; class="notranslate">\; </span>}}^{\mathrm{<span\; class="notranslate">FD</span>}}}{\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; oxf</span>}}^{<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; the\; si</span>}}^{<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; )</span>}<span\; class="notranslate">\; +</span>\frac{\mathrm{<span\; class="notranslate">\; W</span>}}{\mathrm{<span\; class="notranslate">\; L</span>}}{\mathrm{<span\; class="notranslate">\; \&mu;</span>}}_{\mathrm{<span\; class="notranslate">\; no</span>}}\frac{{\mathrm{<span\; class="notranslate">\; Q</span>}}_{\mathrm{<span\; class="notranslate">\; BS</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="Q\; BD"\; filenames="A20051001192800112.png"\; state="\{\{state\}\}">Q</figure-callout></span><figure-callout\; id="2"\; label="Q\; BD"\; filenames="A20051001192800112.png"\; state="\{\{state\}\}">\; </figure-callout>}}_{\mathrm{<span\; class="notranslate">\; </span>}}^{\mathrm{<span\; class="notranslate">BD</span>}}}{\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; oxb</span>}}^{<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; the\; si</span>}}^{<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; )</span>}$

${\mathrm{<span\; class="notranslate">\; I</span>}}_{\mathrm{<span\; class="notranslate">\; diff</span>}}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; W</span>}}{\mathrm{<span\; class="notranslate">\; L</span>}}{\mathrm{<span\; class="notranslate">\; \&mu;</span>}}_{\mathrm{<span\; class="notranslate">\; no</span>}}{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; T</span>}}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; Q</span>}}_{\mathrm{<span\; class="notranslate">\; FD</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; Q</span>}}_{\mathrm{<span\; class="notranslate">\; FS</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; +</span>\frac{\mathrm{<span\; class="notranslate">\; W</span>}}{\mathrm{<span\; class="notranslate">\; L</span>}}{\mathrm{<span\; class="notranslate">\; \&mu;</span>}}_{\mathrm{<span\; class="notranslate">\; no</span>}}{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; T</span>}}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; Q</span>}}_{\mathrm{<span\; class="notranslate">\; BD</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; Q</span>}}_{\mathrm{<span\; class="notranslate">\; BS</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; )</span>$

The charge density of the inversion layer per unit area of the front gate and the back gate can be expressed by the following formula

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

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

In formula (2)(3) $u_T=\frac{\mathrm{KT}}{q},$ $C_{\mathrm{oxf}}^{\&prime;}=\frac{{\mathrm{\&epsiv;}}_{\mathrm{ox}}}{t_{\mathrm{oxf}}},$ $C_{\mathrm{oxb}}^{\&prime;}=\frac{{\mathrm{\&epsiv;}}_{\mathrm{ox}}}{t_{\mathrm{oxb}}}$ respectively represent the gate oxide capacitance of the front gate and the back gate, $C_{\mathrm{Si}}^{\&prime;}=\frac{{\mathrm{\&epsiv;}}_{\mathrm{Si}}}{t_{\mathrm{Si}}}$ denotes the bulk Si capacitance of the channel, ${\mathrm{\&kappa;}}_1=\frac{C^{\&prime;}}{{C^{\&prime;}}_{\mathrm{oxf}}},$ ${\mathrm{\&kappa;}}_2=\frac{C^{\&prime;}}{{C^{\&prime;}}_{\mathrm{oxb}}},$ V _ch =φ _n −φ _F represents the channel potential. Q _FS ＝Q′ _Finv (0), Q _FD ＝Q′ _Finv (L), Q _BS ＝Q′ _Binv (0), Q _BD ＝Q′ _Binv (L); substituting into formula (3) can get

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

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

(4)

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

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

Substituting (4) (2) formula into formula (1) can get the expression of I _ds , and the I _drift term among them can produce the required frequency mixing term as shown in formula (5).

$\frac{\mathrm{<span\; class="notranslate">\; W</span>}}{\mathrm{<span\; class="notranslate">\; L</span>}}<span\; class="notranslate">\; \&Center\; Dot;</span>\frac{{\mathrm{<span\; class="notranslate">\; \&mu;</span>}}_{\mathrm{<span\; class="notranslate">\; no</span>}}<span\; class="notranslate">\; \&Center\; Dot;</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; oxf</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; oxf</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; the\; si</span>}}<span\; class="notranslate">\; )</span>}<span\; class="notranslate">\; \&CenterDot;</span>{\mathrm{<span\; class="notranslate">\; \&kappa;</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&CenterDot;</span>{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; FG</span>}}<span\; class="notranslate">\; \&CenterDot;</span>{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; BG</span>}}<span\; class="notranslate">\; +</span>\frac{\mathrm{<span\; class="notranslate">\; W</span>}}{\mathrm{<span\; class="notranslate">\; L</span>}}<span\; class="notranslate">\; \&CenterDot;</span>\frac{{\mathrm{<span\; class="notranslate">\; \&mu;</span>}}_{\mathrm{<span\; class="notranslate">\; no</span>}}<span\; class="notranslate">\; \&CenterDot;</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; oxf</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; oxb</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; the\; si</span>}}<span\; class="notranslate">\; )</span>}<span\; class="notranslate">\; \&CenterDot;</span>{\mathrm{<span\; class="notranslate">\; \&kappa;</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&CenterDot;</span>{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; FG</span>}}<span\; class="notranslate">\; \&CenterDot;</span>{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; BG</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 5</span>}<span\; class="notranslate">\; )</span>$

Assume that the two input signal expressions of the dual-gate device are: V _FG ＝V _FG0 +V _RF COS(ω _RF t) and V _BG ＝V _LO0 +V _LO COS(ω _LO t); where V _FG0 and V _LO0 are the DC bias voltages at the RF and LO inputs of the dual-gate device, respectively. Substituting the specific expressions of V _FG and V _BG into formula (2) can be obtained that the expression of I _drift contains the term AV _FG V _BG (wherein A represents the coefficient of this term)

${\mathrm{<span\; class="notranslate">\; I</span>}}_{\mathrm{<span\; class="notranslate">\; drift</span>}}<span\; class="notranslate">\; =</span><span\; class="notranslate">\; \&CenterDot;</span><span\; class="notranslate">\; \&CenterDot;</span><span\; class="notranslate">\; \&CenterDot;</span><span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; AV</span>}}_{\mathrm{<span\; class="notranslate">\; FG</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; BG</span>}}<span\; class="notranslate">\; +</span><span\; class="notranslate">\; \&CenterDot;</span><span\; class="notranslate">\; \&Center\; Dot;</span><span\; class="notranslate">\; \&CenterDot;</span><span\; class="notranslate">\; =</span><span\; class="notranslate">\; \&CenterDot;</span><span\; class="notranslate">\; \&Center\; Dot;</span><span\; class="notranslate">\; \&CenterDot;</span><span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; AV</span>}}_{\mathrm{<span\; class="notranslate">\; RF</span>}}\mathrm{<span\; class="notranslate">\; COS</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; RF</span>}}\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; LO</span>}}\mathrm{<span\; class="notranslate">\; COS</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; LO</span>}}\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; +</span><span\; class="notranslate">\; \&CenterDot;</span><span\; class="notranslate">\; \&CenterDot;</span><span\; class="notranslate">\; \&CenterDot;</span>$

$<span\; class="notranslate">\; =</span><span\; class="notranslate">\; \&CenterDot;</span><span\; class="notranslate">\; \&Center\; Dot;</span><span\; class="notranslate">\; \&Center\; Dot;</span><span\; class="notranslate">\; +</span>\frac{\mathrm{<span\; class="notranslate">\; A</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; RF</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; LO</span>}}<span\; class="notranslate">\; [</span>\mathrm{<span\; class="notranslate">\; COS</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; LO</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; RF</span>}}<span\; class="notranslate">\; )</span>\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; COS</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; LO</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; RF</span>}}<span\; class="notranslate">\; )</span>\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; ]</span><span\; class="notranslate">\; +</span><span\; class="notranslate">\; \&CenterDot;</span><span\; class="notranslate">\; \&CenterDot;</span><span\; class="notranslate">\; \&CenterDot;</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 6</span>}<span\; class="notranslate">\; )</span>$

Equation (6) clearly shows that a new frequency component ω _RF ±ω _LO can be generated through the dual-gate device (the plus sign and the minus sign represent the up-conversion and down-conversion components, respectively), thus realizing the frequency mixing function.

The Gilbert-type double-balanced double-gate mixer of the present invention is a mixer composed of four double-gate MOSFET devices, and its specific structure is shown in FIG. 5 . It can be seen from Fig. 5 that the structure MOSFET device can be two double-gate field effect transistors 1 and 2, the positive radio frequency signal is input from the front gate of the double-gate field effect transistor 1, and the positive local oscillator signal is input from the double-gate field effect transistor 1. The back gate of the effect transistor 1 is input, the negative radio frequency signal is input from the front gate of the double gate field effect transistor 2 , and the negative local oscillation signal is input from the back gate of the double gate field effect transistor 2 . Or another way: the positive radio frequency signal is input from the back gate of the double gate field effect transistor 1, the positive local oscillator signal is input from the front gate of the double gate field effect transistor 1, and the negative radio frequency signal is input from the double gate field effect transistor 2 The back gate is input, and the negative local oscillator signal is input from the front gate of the double gate field effect transistor 2 .

The Gilbert-like double-balanced double-gate mixer of the present invention is a mixer composed of four double-gate MOSFET devices. The specific structure is shown in FIG. 6 . It can be seen from Fig. 6 that the structure adopts differential radio frequency signal and local oscillator signal input. The positive radio frequency signal 7 input is connected to the front gate of the double gate field effect transistor 1 and the double gate field effect transistor 2, and the negative radio frequency signal 8 is connected to the front gate of the double gate field effect transistor 3 and the double gate field effect transistor 4 ; The positive local oscillator signal 5 is input and connected to the back gate of the double gate field effect transistor 1 and the double gate field effect transistor 4, and the negative local oscillator signal 6 is input and connected to the back gate of the double gate field effect transistor 2 and the double gate field effect transistor 3 The grid is connected; the capacitor 9 is used to filter out high-frequency components in the output terminals 10 and 11; the resistors 12 and 13 are loads, and active loads composed of inductors and capacitors as loads or MOS devices can also be used. A current source is added to the source end of the double-gate field effect transistor device to stabilize the circuit current. The current source is composed of MOSFET devices, resistors, inductors, capacitors or any combination of the four. Since the simultaneous input of the local oscillator signal and the radio frequency signal is realized in the same MOS device, it is avoided to divide the mixer into a transconductance stage and a switch stage in a stacking manner to achieve frequency mixing in two steps. Its advantages are: 1. It can further reduce the even-numbered odd changes of the mixer; 2. Increase the isolation between the local oscillator signal (LO) and the intermediate frequency signal; 3. Due to the self-mixing of RF and LO signals, the The DC amounts are also canceled out by each other.

After the present invention adopts this structure, the drain-source voltage consumed by the switch stage (or transconductance stage) in the Gilbert type transistor can be saved at least, so that the voltage margin can be reduced by at least one The drain-source value makes the minimum operating voltage required by the mixer less than 1V. Because the structure achieves low voltage and low power consumption at the same time, it is very suitable for the application of deep submicron RF CMOS circuits.

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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