RU2507675C1 - Selective amplifier - Google Patents

Abstract

FIELD: radio engineering, communication.

SUBSTANCE: selective amplifier has an input voltage source, an additional power supply, a voltage-to-current converter, output and additional transistors, two frequency setting resistors, two current-stabilising two-terminal elements, two balancing capacitors. The output transistor has a collector which is connected through a first frequency setting resistor to a first power supply bus. The output of the voltage-to-current converter is connected to the collector of the output transistor and through series-connected first and second balancing capacitors through alternating current to the common power supply bus. The common node of the first and second balancing capacitors is connected through the second frequency setting resistor to the output of the device and is connected to the emitter of the output transistor. The emitter of the output transistor is connected through the first current-stabilising two-terminal element to the second power supply bus. The base of the output transistor is connected to the emitter of the additional transistor and through the second current-stabilising two-terminal element to the first power supply bus.

EFFECT: high Q-factor of the amplitude-frequency characteristic of the selective amplifier and its voltage gain at quasi-resonance frequency fo.

2 cl, 10 dwg

Description

The invention relates to the field of radio engineering and communications and can be used in devices for filtering radio signals, television, radar, etc.

Integrated operational amplifiers with special RC correction elements that form the amplitude-frequency characteristic of the resonant type are widely used today in the tasks of extracting high-frequency signals [1, 2]. However, the classical construction of such selective amplifiers (DUTs) is accompanied by significant energy losses, which are mainly used to ensure the static mode of a sufficiently large number of secondary transistors forming an operational amplifier [1, 2]. In this regard, it is very urgent to build selective amplifiers on bipolar transistors, which provide a narrow spectrum of signals with a sufficiently high quality factor (Q) of the resonance characteristic (Q = 2 ÷ 10) with low power consumption.

Known schemes of DUTs based on bipolar transistors, which provide the formation of the amplitude-frequency characteristics of the voltage gain in a given frequency range Δf = f _in -f _n [3-20]. Moreover, their upper cutoff frequency f _{in is} sometimes formed by the inertia of the transistors of the circuit (capacitance per substrate), and the lower f _n is determined by corrective capacitors.

The closest prototype of the claimed device is a selective amplifier, presented in patent US 5.304.946, fig. 24. It contains an input voltage source 1, connected to the input of the voltage-current converter 2, an output transistor 3, the collector of which through the first 4 frequency-setting resistor is connected to the first 5 bus of the power source, auxiliary voltage source 6, the second 7 frequency-setting resistor, the first 8 current-stabilizing bipolar, the first 9 and second 10 correction capacitors, the second 11 bus power supply.

амплитудно-частотной характеристики (АЧХ) и коэффициент усиления по напряжению К₀>1 на частоте квазирезонанса (f₀).A significant drawback of the known YiU prototype is that it does not provide high quality factor $$Q\approx \frac{f_0}{f_{\mathrm{at}}-f_n}$$

amplitude-frequency characteristics (AFC) and voltage gain K ₀ > 1 at the quasi-resonance frequency (f ₀ ).

The main objective of the invention is to increase the quality factor of the frequency response of the DUT and its gain in voltage (K ₀ ) at a frequency of quasi-resonance f ₀ . This allows in some cases to reduce the overall energy consumption and implement a high-quality selective device.

The problem is solved in that in the selective amplifier, Fig. 1, containing an input voltage source 1, connected to the input of the voltage-current converter 2, an output transistor 3, the collector of which is connected through the first 4 frequency-setting resistor to the first 5 bus of the power source, auxiliary voltage source 6, second 7 frequency-setting resistor, first 8 current-stabilizing bipolar, first 9 and second 10 correction capacitors, second 11 power supply bus, new elements and communications are provided - output 12 pre The voltage-current transmitter 2 is connected to the collector of the output transistor 3 and through the first 9 and second 10 correction capacitors connected in series with alternating current connected to the common bus of power supplies 13, the common node of the first 9 and second 10 correction capacitors is connected through the second 7 frequency-setting resistor with the output of the device 14 and connected to the emitter of the output transistor 3, the emitter of the output transistor 3 through the first 8 current-stabilizing two-terminal is connected to the second 11 bus power source, the base is output Nogo transistor 3 is connected to the emitter of transistor 15 and further through the second bipole tokostabiliziruyuschy 16 connected to the first power supply bus 5, an additional collector of the transistor 15 is connected to the emitter of the output transistor 3, and its base connected to the auxiliary voltage supply 6.

The amplifier circuit of the prototype is shown in figure 1. Figure 2 presents a diagram of the inventive device in accordance with claim 1 and claim 2 of the claims.

Figure 3 presents a diagram of the inventive device with a specific implementation of the Converter "voltage-current" 2 in the form of a differential cascade on the elements 17, 18 and 19.

Figure 4 presents a diagram of the inventive device in accordance with claim 2 of the claims.

FIG. 5 is a diagram of the DUT of FIG. 2 without an additional current amplifier 12 in a Cadence environment on SiGe transistor models. Here, input converter 2 is implemented on transistor Q3.

Figure 6 shows the logarithmic amplitude-frequency (LFC) and phase-frequency (PFC) characteristics of the DUT of Fig. 5 in a wide frequency range from 1 kHz to 100 GHz at Rvar = 0, Cvar = 700 fF, Ivar = 200 μA.

Figure 7 shows the dependence of the Q factor Q and the resonant frequency f _{0 of the} DUT of Fig. 5 from the current Ivar.

FIG. 8 shows the DUT of FIG. 4 with an additional current amplifier 20 (K _i ) in a Cadence environment on SiGe transistor modules.

Figure 9 shows the LACH and phase response of the DUT of Fig. 8 in a wide frequency range from 1 kHz to 100 GHz at Rvar = 0, Cvar = 700 fF, Ki = 25, Ivar = 50 μA.

Figure 10 shows the dependence of the quality factor Q of the DUT of Fig. 8 on the current transfer coefficient Ki of the additional current amplifier 20.

The selective amplifier of Fig. 2 contains an input voltage source 1, connected to the input of the voltage-current converter 2, an output transistor 3, the collector of which is connected through the first 4 frequency-setting resistor to the first 5 bus of the power source, the auxiliary voltage source 6, and the second 7 frequency-setting resistor , the first 8 current-stabilizing bipolar, the first 9 and second 10 correction capacitors, the second 11 bus power supply. The output 12 of the voltage-current converter 2 is connected to the collector of the output transistor 3 and through the first 9 and second 10 correction capacitors connected in series with alternating current connected to a common bus power supply 13, a common node of the first 9 and second 10 correction capacitors through the second 7 frequency-setting the resistor is connected to the output of the device 14 and connected to the emitter of the output transistor 3, the emitter of the output transistor 3 through the first 8 current-stabilizing two-terminal is connected to the second 11 bus power source I, the base of the output transistor 3 is connected to the emitter of the additional transistor 15 and through the second 16 the current-stabilizing two-terminal is connected to the first 5 bus of the power supply, the collector of the additional transistor 15 is connected to the emitter of the output transistor 3, and its base is connected to the auxiliary voltage source 6.

Figure 3 presents the selective amplifier of figure 2, in which the input Converter "voltage-current" 2 is implemented on transistors 17, 18 and the current source 19.

In Fig. 4, in accordance with claim 2, the collector of the additional transistor 15 is connected to the emitter of the output transistor 3 through an additional current amplifier 20 through a current mirror. In the particular case, an additional output of the device may be a node 21.

Consider the operation of the circuit of figure 2.

Source input signal _Rin u (1) by an input transducer "voltage-current" 2 changes the current collector circuit of the transistor 3. Character collector load of the transistor formed by the resistors 4 and 7, and capacitors 9 and 10 converts this current to a resistor current 7 output circuit Yiwu. Moreover, the presence of a capacitive divider formed by capacitors 9 and 10, provides a functional dependence of this current, corresponding to the frequency characteristics of the selective amplifier. Indeed, capacitor 9 reduces this current in the low-frequency region (f <f ₀ ), where f ₀ is the DUT quasi-resonance frequency, and capacitor 10 reduces the output voltage in the high-frequency region (f> f ₀ ). Thus, the used collector load provides the necessary form of the amplitude and phase frequency characteristics of the DUT circuit. Because of this, the action of the feedback loop is aimed at increasing the quality factor Q and the gain K _{0 of the} DUT.

The complex transfer coefficient of the DUT, Fig. 2, as the ratio of the output voltage (output of the device 14) to the input voltage u _in (1) is determined by the formula, which can be obtained using the methods of analysis of electronic circuits:

$$K(jf)=\frac{u_{\mathrm{fourteen}}}{u_{\mathrm{at}x}}=K_0\frac{jf\frac{f_0}{\mathrm{<figure-callout\; id="0"\; label="Q\; f"\; filenames="00000017.png,00000018.png"\; state="\{\{state\}\}">Q\; </figure-callout>}}}{f_{}^{}},\left(\mathrm{one}\right)$$

where f is the frequency of the input signal;

f ₀ is the frequency of the quasi-resonance of the selective amplifier;

Q is the quality factor of the frequency response of the selective amplifier;

To ₀ is the gain of the DUT at the frequency of quasi-resonance f ₀ .

Moreover

$${\mathrm{<figure-callout\; id="0"\; label="f"\; filenames="00000017.png,00000018.png"\; state="\{\{state\}\}">f</figure-callout>}}_0=\frac{\mathrm{one}}{2\pi \sqrt{C_9{C}_{10}{R}_{\mathrm{four}}({\mathrm{<figure-callout\; id="7"\; label="R"\; filenames="00000016.png,00000017.png"\; state="\{\{state\}\}">R</figure-callout>}}_7+h_{11.3})}},\left(2\right)$$

where C ₉ , C ₁₀ , R ₄ , R ₇ are the parameters of the elements 9, 10, 4 and 7;

h _11.i is the h-parameter of the i-th transistor in the circuit with a common base.

The quality factor of the DUT is determined by the formula

$$Q^{-\mathrm{one}}={\mathrm{<figure-callout\; id="0"\; label="D"\; filenames="00000017.png,00000018.png"\; state="\{\{state\}\}">D</figure-callout>}}_0+\sqrt{\frac{C_9}{C_{10}}}\sqrt{\frac{R_{\mathrm{four}}}{{\mathrm{<figure-callout\; id="7"\; label="R"\; filenames="00000016.png,00000017.png"\; state="\{\{state\}\}">R</figure-callout>}}_7+h_{11.3}}}[\mathrm{one}-{\alpha }_3(\mathrm{one}+{\alpha }_{\mathrm{fifteen}}(\mathrm{one}-{\alpha }_3))],\left(3\right)$$

where α _i is the current transfer coefficient of the emitter of the i-th transistor;

эквивалентное затухание пассивной частото-зависимой цепи. $${\mathrm{<figure-callout\; id="0"\; label="D"\; filenames="00000017.png,00000018.png"\; state="\{\{state\}\}">D</figure-callout>}}_0=\left(\sqrt{\frac{C_9}{{\mathrm{<figure-callout\; id="10"\; label="C"\; filenames="00000016.png,00000017.png"\; state="\{\{state\}\}">C</figure-callout>}}_{10}}}+\sqrt{\frac{C_{10}}{C_9}}\right)\sqrt{\frac{{\mathrm{<figure-callout\; id="7"\; label="R"\; filenames="00000016.png,00000017.png"\; state="\{\{state\}\}">R</figure-callout>}}_7+h_{11.3}}{R_{\mathrm{four}}}}$$

equivalent attenuation of a passive frequency-dependent circuit.

By choosing the parameters of the elements included in the formula (3), it is possible to provide Q >> 1.

The formula for the gain K ₀ in the complex transfer coefficient (1) has the form

$${\mathrm{<figure-callout\; id="0"\; label="K"\; filenames="00000017.png,00000018.png"\; state="\{\{state\}\}">K</figure-callout>}}_0=-Q{S}_2\sqrt{R_{\mathrm{four}}(R_7+h_{11.3})}\sqrt{\frac{C_9}{{\mathrm{<figure-callout\; id="10"\; label="C"\; filenames="00000016.png,00000017.png"\; state="\{\{state\}\}">C</figure-callout>}}_{10}}},\left(\mathrm{four}\right)$$

where S ₂ - the steepness of the input Converter "voltage-current" 2.

An important feature of the circuit is the possibility of realizing high quality factor and optimizing its parametric sensitivity. The optimal ratio is the equality of the capacitance of the capacitors 9 and 10 (C ₉ = C ₁₀ ). In this regard, the necessary maximum value of the quality factor Q can be provided by choosing the optimal ratio of the resistances of resistors 4 and 7.

From relation (3) it follows that when implementing the parametric condition:

$${\mathrm{<figure-callout\; id="7"\; label="R"\; filenames="00000016.png,00000017.png"\; state="\{\{state\}\}">R</figure-callout>}}_7=\frac{R_{\mathrm{four}}}{2}[\mathrm{one}-{\alpha }_3(\mathrm{one}+{\alpha }_{\mathrm{fifteen}}(\mathrm{one}-{\alpha }_3))]-h_{11.3},\left(5\right)$$

the quality factor of the DUT takes its maximum value

$$Q_{\max }=\frac{\mathrm{one}}{2\sqrt{2}}\cdot \frac{\mathrm{one}}{\sqrt{\mathrm{one}-{\alpha }_3(\mathrm{one}+{\alpha }_{\mathrm{fifteen}}(\mathrm{one}-{\alpha }_3))}},\left(6\right)$$

For example, at α ₃ ≈α ₁₅ ≈0.99, Q _max = 25, and without the special feedbacks indicated in the scheme, this value does not exceed 3.5.

When lowering the numerical values of the Q factor in the DUT scheme, it is possible to minimize its parametric sensitivity when the condition C ₉ = C _{10 is} fulfilled. Then:

$$Q=\frac{\mathrm{one}}{2}\sqrt{\frac{R_{\mathrm{four}}}{{\mathrm{<figure-callout\; id="7"\; label="R"\; filenames="00000016.png,00000017.png"\; state="\{\{state\}\}">R</figure-callout>}}_7+h_{11.3}}}<<Q\max ,\left(7\right)$$

and its parametric sensitivity is globally minimized:

$$S_{C_{{}_9}}^Q=S_{C_{{}_{10}}}^Q=0;S_{R_{\mathrm{four}}}^Q=-{\mathrm{<figure-callout\; id="7"\; label="S\; R"\; filenames="00000016.png,00000017.png"\; state="\{\{state\}\}">S\; </figure-callout>}}_{R_{}}^{{}_7+h_{11.3}}=\frac{\mathrm{<figure-callout\; id="2"\; label="one"\; filenames="00000016.png,00000017.png"\; state="\{\{state\}\}">one</figure-callout>}}{2},\left(8\right)$$

These features provide the versatility of the scheme of the claimed IU.

Presented in figure 4, the development of the circuit diagram of the DUT of figure 2 allows you to remove the restriction included in the ratio (7). Valid in this case:

$$Q^{-\mathrm{one}}={\mathrm{<figure-callout\; id="0"\; label="D"\; filenames="00000017.png,00000018.png"\; state="\{\{state\}\}">D</figure-callout>}}_0+\sqrt{\frac{C_9}{C_{10}}}\sqrt{\frac{R_{\mathrm{four}}}{{\mathrm{<figure-callout\; id="7"\; label="R"\; filenames="00000016.png,00000017.png"\; state="\{\{state\}\}">R</figure-callout>}}_7+h_{11.3}}}[\mathrm{one}-K_i{\alpha }_3(\mathrm{one}+{\alpha }_{\mathrm{fifteen}}(\mathrm{one}-{\alpha }_3))],\left(9\right)$$

where K _i is the current gain of the additional current amplifier 20.

Therefore, under the parametric condition

$$K_i=\frac{\mathrm{one}}{{\mathrm{<figure-callout\; id="3"\; label="\alpha "\; filenames="00000016.png,00000017.png"\; state="\{\{state\}\}">\alpha </figure-callout>}}_3+{\alpha }_{\mathrm{fifteen}}{\alpha }_3(\mathrm{one}-{\alpha }_3)},\left(10\right)$$

the quality factor of the circuit of the DUT of Fig. 4 while maintaining the parametric sensitivities (8) takes on the value

$$Q=\frac{\mathrm{one}}{2}\sqrt{\frac{R_{\mathrm{four}}}{{\mathrm{<figure-callout\; id="7"\; label="R"\; filenames="00000016.png,00000017.png"\; state="\{\{state\}\}">R</figure-callout>}}_7+h_{11.3}}},\left(\mathrm{eleven}\right)$$

In addition, the specified modification of the IE allows you to use the conditions of uniformity (R ₄ = R ₇ ). Then the quality factor:

$$Q^{-\mathrm{one}}=3-K_i{\alpha }_3[\mathrm{one}+{\alpha }_{\mathrm{fifteen}}(\mathrm{one}-{\alpha }_3)].\left(12\right)$$

Consequently, by choosing K _i it is possible to realize a given quality factor of the DUT of FIG.

Presented in Fig.6 and 7, as well as Fig.9 and 10, the simulation results of the proposed DUT confirm the indicated properties of the claimed schemes.

Thus, the proposed circuit solutions of the DUT are characterized by higher values of the gain Co at a frequency of quasi-resonance f ₀ , as well as increased values of the quality factor Q, which characterizes its selective properties.

Literature

 1. Design of Bipolar Differential OpAmps with Unity Gain Bandwidth up to 23 GHz / N.Prokopenko, A. Budyakov, K.Schmalz, C.Scheytt, P. Ostrovskyy // Proceeding of the 4-th European Conference on Circuits and Systems for Communications - ECCSC'08 / - Politehnica University, Bucharest, Romania: July 10-11, 2008. - pp.50-53

2. Microwave SF blocks of communication systems based on fully differential operational amplifiers / Prokopenko NN, Budyakov AS, K. Schmalz, S.Scheytt // Problems of Developing Advanced Micro- and Nanoelectronic Systems - 2010. Proceedings / under the general. ed. Academician of the Russian Academy of Sciences A.L. Stempkovsky. - M .: IPPM RAS, 2010. - P.583-586

3. Ezhkov Yu.S. Handbook of amplifier circuitry. - 2nd ed., Revised. - M., IP RadioSoft, 2002. - P. 21, Fig. 1.10c.

4. Volgin L.I. Synthesis and circuitry of analog electronic devices in the elemental basis of amplifiers and current repeaters / L.I. Volgin, A.I. Zarukin; under. general ed. L.I. Volgina. - Ulyanovsk: UlSTU, 2005. - P.33, Fig. 27.

5. Patent US 5,304,946 fig.22.

6. Patent US 7.113.043.

7. Patent US7.598.810.

8. Patent application US 2005/0146389 fig. 3.

9. Patent application US 2008/0231369 fig.2.

10. Patent US 7.110.742 fig. 5.

11. Patent US 6.515.547 fig.4a.

12. US patent 7.633.344 fig. 7.

13. Patent US 7.847.636 fig.4a.

14. Patent US7.786.807.

15. Patent application US 20070296501.

16. Patent application US 2008/0018403

17. Patent US 351.865

18. Patent US 7.737.790

19. Patent US 4.151.483 fig.2

20. Patent application JP 2003011396

Claims (2)

1. A selective amplifier containing an input voltage source (1) connected to the input of the voltage-current converter (2), an output transistor (3), whose collector is connected through the first (4) frequency-setting resistor to the first (5) bus of the power source , auxiliary voltage source (6), second (7) frequency-setting resistor, first (8) current-stabilizing two-terminal, first (9) and second (10) correction capacitors, second (11) power supply bus, characterized in that output (12) voltage-current transducer (2) is connected to the call the output transistor (3) and through the first (9) and second (10) correction capacitors connected in series through alternating current connected to a common bus power sources (13), the common node of the first (9) and second (10) correction capacitors through the second ( 7) the frequency-setting resistor is connected to the output of the device (14) and connected to the emitter of the output transistor (3), the emitter of the output transistor (3) through the first (8) current-stabilizing two-terminal device is connected to the second (11) bus of the power source, the base of the output transistor (3) connected to e by a mitter of an additional transistor (15) and through a second (16) current-stabilizing two-terminal device connected to the first (5) bus of the power source, the collector of the additional transistor (15) is connected to the emitter of the output transistor (3), and its base is connected to the auxiliary voltage source (6) . 2. The selective amplifier according to claim 1, characterized in that the collector of the additional transistor (15) is connected to the emitter of the output transistor (3) through an additional current amplifier (20).

Images