RU2474039C1 - Selective amplifier - Google Patents

Abstract

FIELD: radio engineering.

SUBSTANCE: selective amplifier includes the first (1) input transistor, input signal source (2), the first (3) current-stabilising bipole, the first (4) power supply bus, the second (5) input transistor, the first current mirror (6), the second (7) power supply bus, the second (8) current mirror, the third (9) current mirror, output of device (10), the second (11) current-stabilising bipole, the first frequency-setting resistor (12) and the first balancing capacitor (13), the second (14) frequency-setting resistor and the second (15) balancing capacitor.

EFFECT: improving Q factor of amplitude-frequency response of the amplifier and its voltage amplification factor at quasi-resonance frequency f₀.

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Description

The invention relates to the field of radio engineering and communication and can be used in microwave filtering devices of radio signals from cellular communication systems, satellite television, radar, etc.

Integrated operational amplifiers with special RC correction elements that form the amplitude-frequency characteristic of the resonance type are widely used today in the tasks of extracting high-frequency and microwave signals [1, 2]. However, the classical construction of such selective amplifiers (RC filters) is accompanied by significant energy losses, which are mainly used to ensure the static mode of a sufficiently large number of transistors forming an operational amplifier of the microwave range [1, 2]. In this regard, it is quite urgent to build microwave selective amplifiers (DUTs) on three to four transistors, which provide a narrow spectrum of signals with a sufficiently high quality factor of the resonance characteristic Q = 2 ÷ 10 and f ₀ = 1 ÷ 5 GHz.

Known amplifier circuits integrated into the architecture of RC filters based on 3-5 transistors that provide the formation of the amplitude-frequency characteristics of the voltage gain in a given frequency range Δf = f _in -f _n [3-10]. 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 a correction capacitor.

The closest prototype of the claimed device is a selective amplifier (IU), presented in patent US 5.371.476. It contains the first 1 input transistor, the base of which is connected to the input signal source 2, and the emitter is connected to the first 4 bus of the power supply through the first 3 current-stabilizing two-terminal circuits, the second 5 input transistor, the first current mirror 6, matched with the second 7 bus of the power supply, input which is connected to the collector of the first 1 input transistor, the second 8 current mirror, matched with the second 7 bus power source, the input of which is connected to the second 5 input transistor, the third 9 current mirror, matched with the first 4 bus power source, the input of which is connected to the current output of the first 6 current mirror, and the current output is connected to the current output of the second 8 current mirror and the output of the device 10.

амплитудно-частотной характеристики и коэффициент усиления по напряжению К₀>1 на частоте квазирезонанса (f₀).A significant disadvantage of the known device is that it does not provide high quality factor

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

The main objective of the invention is to increase the quality factor of the frequency response of the amplifier and its voltage gain at the frequency of quasi-resonance f ₀ . This allows in some cases to reduce the total power consumption and implement a high-quality microwave device with f ₀ = 1 ÷ 5 GHz.

The problem is solved in that in a selective amplifier (figure 1) containing the first 1 input transistor, the base of which is connected to the input signal 2, and the emitter is connected through the first 3 current-stabilizing two-terminal to the first 4 bus of the power source, the second 5 input transistor, the first current mirror 6, coordinated with the second 7 bus power source, the input of which is connected to the collector of the first 1 input transistor, the second 8 current mirror, matched with the second 7 bus power source, the input of which is connected to with the fifth input transistor, the third 9 current mirror, matched with the first 4 bus of the power source, the input of which is connected to the current output of the first 6 current mirror, and the current output is connected to the current output of the second 8 current mirror and the output of device 10, new elements and connections are provided - the emitter of the second 5 input transistor through the second 11 current-stabilizing bipolar connected to the first 4 bus power supply, between the emitters of the first 1 and second 5 input transistors are connected in series to the first hour a current-sensing resistor 12 and a first correction capacitor 13, the base of the second 5 input transistor is connected to the output of the device 10, and between the common bus of the power supplies and the output 10 of the device, alternating current is connected to the second 14 frequency-setting resistor and the second 15 correction capacitor in parallel.

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 shows a diagram of the inventive DUT of figure 1 in a Cadence environment on SiGe transistors.

Figure 4 shows the dependence of the voltage transfer coefficient on the frequency of the DUT of figure 3 for capacitors 13 (15) C ₁₃ = C ₁₅ = C = 200 fF and R ₁₂ = R ₁₄ = R = 700 Ohms, and in the combined drawing of FIG. .5 is the frequency dependence of the gain and phase shift of the DUT of FIG. 3.

Figure 6 shows the dependence of the voltage transfer coefficient and phase shift of the DUT of Figure 3 on the frequency for other parameters of the circuit elements of Figure 3 (C = 600 fF, R = 220 Ohms).

The selective amplifier of figure 2 contains the first 1 input transistor, the base of which is connected to the input signal source 2, and the emitter is connected through the first 3 current-stabilizing two-terminal to the first 4 bus of the power supply, the second 5 input transistor, the first current mirror 6, matched with the second 7 bus a power source, the input of which is connected to the collector of the first 1 input transistor, the second 8 current mirror, consistent with the second 7 bus power source, the input of which is connected to the second 5 input transistor, the third 9 currents e mirror, consistent with the first 4 bus power source, the input of which is connected to the current output of the first 6 current mirror, and the current output is connected to the current output of the second 8 current mirror and the output of the device 10. The emitter of the second 5 input transistor through the second 11 current-stabilizing two-terminal connected the first 4 bus power source, between the emitters of the first 1 and second 5 input transistors connected in series to the first frequency-setting resistor 12 and the first correction capacitor 13, the base of the second 5 input -stand transistor connected to the output device 10, and between the power supply common bus 10 and the output devices are turned on by alternating current 14 parallel-connected second frequency defining a second resistor and the adjustment capacitor 15.

In figure 2, in accordance with claim 2 of the claims, the current transfer coefficient K _{i of the} first 6 and second 8 current mirrors are identical and have the same values in the range K _i = 1 ÷ 2, and the current transfer coefficient of the third 9 current mirror is always close to unit.

A wide range of classical solutions described in the technical literature can be used as current mirrors 6, 8, 9.

Consider the operation of the DUT figure 2.

The complex voltage transfer coefficient K _y (jf) of the selective amplifier of FIG. 2 is determined by the ratio that can be obtained using electronic circuit analysis methods:

where f is the signal frequency;

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 ;

f ₀ is the frequency of quasi-resonance.

Moreover

where C ₁₃ , C ₁₅ - the capacitance of the capacitors 13 and 15;

- входное сопротивление i-го транзистора в схеме с общей базой;

- input resistance of the i-th transistor in a circuit with a common base;

φ _t ≈25 mV - temperature potential;

I _ei is the static current of the emitter of the i-th transistor;

α _i <1 - current gain of the emitter of the i-th transistor.

If we choose τ ₁ = τ ₂ , R ₁₄ = R ₁₂ + h _11.1 + h _11.5 then the equations for Q (6) and K ₀ (5) are significantly simplified:

This allows, due to a targeted selection of the parameters of the elements included in formula (7), to obtain the specified values of Q (8) and K ₀ (9).

These theoretical findings confirm the graphs of Figures 4-6.

Thus, the claimed circuit solution is characterized by higher values of the gain at the frequency of the quasi-resonance f ₀ and increased values of the quality factor Q1, characterizing its selective properties.

BIBLIOGRAPHIC LIST

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, C.Scheytt // Problems of developing promising micro- and nanoelectronic systems. - 2010. Proceedings / Under the total. ed. Acad. RAS A.L. Stempkovsky. - M .: IPPM RAS, 2010. - P.583-586.

3. Operational amplifier 1427UD1 (NE5517) // Reference: operational amplifiers and comparators (Averbukh VD and others). - Moscow: Publishing House Dodeka-XXI, 2001. - p. 225.

4. Operational amplifier SF3078 // Reference: operational amplifiers and comparators (Averbukh VD and others). - M.: Publishing House Dodeka-XXI, 2001. - p. 106.

5. Shkritek P. Reference manual for sound circuitry. - M .: Mir, 1991. - The operational amplifier LM13600, Fig. 8.2.1.

6. Patent US 5.371.476.

7. Patent US 3.982.197.

8. Patent US 4.799.026.

9. Patent US 6.750.714.

10. Patent US 4.241.315 fig. 4.

Claims (2)

1. A selective amplifier containing the first (1) input transistor, the base of which is connected to the input signal source (2), and the emitter is connected through the first (3) current-stabilizing two-terminal device to the first (4) bus of the power source, the second (5) input transistor, the first current mirror (6), matched to the second (7) bus of the power source, the input of which is connected to the collector of the first (1) input transistor, the second (8) current mirror, matched to the second (7) bus of the power source, the input of which is connected to second (5) input transistor, tr Tie (9) current mirror, consistent with the first (4) bus power source, the input of which is connected to the current output of the first (6) current mirror, and the current output is connected to the current output of the second (8) current mirror and the output of the device (10), characterized in that the emitter of the second (5) input transistor is connected through the second (11) current-stabilizing two-terminal to the first (4) bus of the power supply, between the emitters of the first (1) and second (5) input transistors are connected in series with the first frequency-setting resistor ( 12) and the first a correction capacitor (13), the base of the second (5) input transistor is connected to the output of the device (10), and between the common bus of power supplies and the output (10) of the device, alternating current is connected to the second (14) frequency-setting resistor and the second ( 15) correction capacitor. 2. The selective amplifier according to claim 1, characterized in that the current transfer coefficient K _{i of the} first (6) and second (8) current mirrors are identical and have the same values in the range of K _i = 1 ÷ 2, and the current transfer coefficient of the third (9) the current mirror is always close to unity.

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