RU2485675C1 - Selective amplifier - Google Patents

Abstract

FIELD: radio engineering, communications.

SUBSTANCE: between a collector of the first (2) input transistor and an emitter of the second (6) input transistor there are the following serially connected components: the third (11) resistor and the second (13) correcting capacitor, between the collector of the second (2) input transistor and buses of the first (5) and second (9) sources of power supply there is the third (16) correcting capacitor connected by AC, the base of the output transistor (14) is connected to the collector of the second (6) input transistor, its collector is connected to the second (9) bus of the power supply source, and the emitter is connected with the output of the device (17) and via the third (18) current-stabilising dipole to the first (5) bus of the power supply source, besides, between the output of the device (17) and the input of the device (1) there is the fourth (12) resistor connected.

EFFECT: higher quality of amplifier amplitude-frequency characteristic and its amplification ratio by voltage at quasiresonance frequency f₀, possibility to reduce overall power consumption and to implement a high-quality selective microwave device.

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Description

The present invention relates to the field of radio engineering and communications 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 problems of extracting high-frequency and microwave 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 transistors forming an operational amplifier of the microwave range [1, 2]. In this regard, the task of constructing microwave selective amplifier DIs on three to four transistors, providing the selection of a narrow spectrum of signals with a sufficiently high quality factor of the resonant characteristic Q = 2 ÷ 10 and f ₀ = 1 ÷ 5 GHz at low power consumption, is quite relevant.

Known amplifier circuits integrated into the architecture of RC filters 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 [3-15]. 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 the input correction capacitor.

The closest prototype of the claimed device is a selective amplifier, presented in patent US 6.642.794. It contains input 1, which is connected to the emitter of the first 2 input transistor through the first 3 correction capacitor, the first current-stabilizing two-terminal 4 connected between the emitter of the first 2 input transistor and the first 5 bus of the power source, the second 6 input transistor, the base of which is connected to the base of the first 2 input transistor and connected to the auxiliary voltage source 7, the first 8 resistor connected between the second 9 bus of the power source and the collector of the first 2 input transistor, the second 10 resistor is turned on between the second 9 bus of the power supply and the collector of the second 6 input transistor, the third 11 and fourth 12 resistors, the second 13 correction capacitor, the output transistor 14 and the second 15 current-stabilizing two-terminal device.

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 to implement a high-quality microwave device with f ₀ = 1 ÷ 5 GHz.

The problem is solved in that in the amplifier of figure 1, containing input 1, which is connected to the emitter of the first 2 input transistor through the first 3 correction capacitor, the first current-stabilizing two-terminal 4 connected between the emitter of the first 2 input transistor and the first 5 bus power source, the second 6 input transistor, the base of which is connected to the base of the first 2 input transistor and is connected to the auxiliary voltage source 7, the first 8 resistor connected between the second 9 bus of the power source and the collector ne 2 input transistors, a second 10 resistor connected between the second 9 bus of the power source and the collector of the second 6 input transistor, the third 11 and fourth 12 resistors, the second 13 correction capacitor, the output transistor 14 and the second 15 current-stabilizing two-pole, new elements and communications are provided - between the collector of the first 2 input transistor and the emitter of the second 6 input transistor, a third 11 resistor and a second 13 correction capacitor are connected in series, between the collector of the second 2 input about the transistor and the buses of the first 5 and second 9 power sources, an alternating current third 16 correction capacitor is turned on, the base of the output transistor 14 is connected to the collector of the second 6 input transistor, its collector is connected to the second 9 bus of the power source, and the emitter is connected to the output of the device 17 through the third 18, the current-stabilizing two-terminal is connected to the first 5 bus of the power source, and a fourth 12 resistor is connected between the output of the device 17 and the input of the device 1.

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

The drawing of Fig. 3 shows a diagram of the DUT of Fig. 2 in a Cadence environment on SiGe models of transistors with an input voltage-current converter on transistor Q17.

The drawing of figure 4 shows the logarithmic amplitude-frequency (LAC) and phase-frequency characteristics of the DUT of figure 3 in the frequency range from 100 MHz to 10 GHz, and in the drawing of figure 5 - in the frequency range from 100 kHz to 100 GHz.

The selective amplifier of figure 2 contains input 1, which is connected to the emitter of the first 2 input transistor through the first 3 correction capacitor, the first current-stabilizing two-terminal 4 connected between the emitter of the first 2 input transistor and the first 5 bus of the power source, the second 6 input transistor, the base of which is connected with the base of the first 2 input transistor and connected to the auxiliary voltage source 7, the first 8 resistor connected between the second 9 bus of the power source and the collector of the first 2 input transistor , a second 10 resistor connected between the second 9 bus of the power source and the collector of the second 6 input transistor, the third 11 and fourth 12 resistors, the second 13 correction capacitor, the output transistor 14 and the second 15 current-stabilizing two-terminal device. Between the collector of the first 2 input transistor and the emitter of the second 6 input transistor, a third 11 resistor and a second 13 correction capacitor are connected in series, between the collector of the second 2 input transistor and the buses of the first 5 and second 9 power supplies, the third 16 correction capacitor is connected via alternating current, the base of the output transistor 14 is connected to the collector of the second 6 input transistor, its collector is connected to the second 9 bus of the power source, and the emitter is connected to the output of the device 17 and through the third 18 current-stabilizing bipolar connected to the first 5 bus power source, and between the output of the device 17 and the input of the device 1 is connected to the fourth 12 resistor.

Consider the operation of the DUT figure 2.

The interaction of the output circuit of the DUT through a serial connection of the resistor 12 and the capacitor 3 with the emitter of the transistor 2 provides the implementation of the feedback loop. Moreover, due to the differential properties of this circuit in the low frequency region (f << f ₀ ), this feedback is reactive, and due to the integrating properties of the collector load of transistor 2 (resistor 8 and capacitor 16) in the high frequency region (f >> f ₀ ) the depth of this feedback decreases asymptotically. It is these properties of the emitter and collector circuits of transistor 2 that provide feedback materiality at the quasi-resonance frequency f _{0 of the} DUT, and therefore its action is aimed at increasing the quality factor Q and the gain K _{0 of the} device while maintaining the specified frequency f ₀ .

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:

α _i is the transmission coefficient of the emitter current of the i-th transistor.

An important feature of the scheme of figure 2 is the ability to implement DUT with various consumer properties. So when choosing a condition

by choosing the parameter γ (as can be seen from relation (3)), additional parametric conditions can be realized

and ensure the implementation of the quality factor, which is determined by the following analytical expressions

Thus, in the circuit of FIG. 2, the Q factor is directly determined by the resistance of the resistive elements of the circuit. Indeed, even with R ₁₁ << R ₈

Therefore, by choosing the ratio between R ₁₀ and R _12, it is possible to provide the required value of Q without changing the conditions for obtaining a given frequency of quasi-resonance (2).

Note that condition (5) potentially provides an increase in the dynamic range of the DUT circuit. Under the same conditions, due to γ≤2 (see relations (3) and (8)), the gain of the DUT K _{0 is} practically determined by the realized quality factor, which emphasizes the structural advantages of the proposed scheme. Moreover, as follows from (2), the value of the frequency of quasi-resonance f ₀ and its parametric sensitivity do not change.

These theoretical conclusions confirm the graphs of figure 4, figure 5.

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 Q, which characterizes 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, S.Scheytt // Problems of developing promising 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. Patent US 6.642.794, fig. 4.

4. Patent US 5.914.639, fig. 2.

5. Patent US 2011/0294446.

6. Patent WO / 2006/077525.

7. Patent application US 2007/0040604, fig. 3.

8. Patent application US 2006/018695, fig. 3.

9. Patent WO / 2003/052925 A1, fig. 3.

10. Patent application US 2011/0109388.

11. Patent application US 2010/0201437.

12. Patent US 5.267.518.

13. Patent US 5.298.802.

14. US patent 6.972.624.

15. Patent US 7.538.616.

Claims (2)

1. A selective amplifier, the input (1) of which is connected to the emitter of the first (2) input transistor through the first (3) correction capacitor, the first current-stabilizing two-terminal device (4) connected between the emitter of the first (2) input transistor and the first (5) source bus power supply, a second (6) input transistor, the base of which is connected to the base of the first (2) input transistor and is connected to an auxiliary voltage source (7), the first (8) resistor connected between the second (9) power supply bus and the collector of the first (2) ) input transistor a, a second (10) resistor connected between the second (9) bus of the power supply and the collector of the second (6) input transistor, the third (11) and fourth (12) resistors, the second (13) correction capacitor, the output transistor (14) and a second (15) current-stabilizing two-terminal device, characterized in that a third (11) resistor and a second (13) correction capacitor are connected in series between the collector of the first (2) input transistor and the emitter of the second (6) input transistor, between the collector of the second (2) input transistor and busbar primary about (5) and second (9) power sources, the third (16) correction capacitor is turned on by alternating current, the base of the output transistor (14) is connected to the collector of the second (6) input transistor, its collector is connected to the second (9) bus of the power source, and the emitter is connected to the output of the device (17) and through the third (18) current-stabilizing two-terminal device is connected to the first (5) bus of the power source, and a fourth (12) resistor is connected between the output of the device (17) and the input of the device (1). 2. A selective amplifier according to claim 1, characterized in that a signal source with a high output resistance is connected to the input of the device (1).

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