RU2572388C1 - Extended frequency band transistor amplifier - Google Patents

Abstract

FIELD: radio engineering, communication.

SUBSTANCE: extended frequency band transistor amplifier comprises an input voltage-to-current converter (1), the input of which is connected to a signal source (2), and the current output is connected to a power supply bus (3) through a collector load (4) resistor, a non-inverting voltage amplifier (5), the input of which is connected to the current output of the input voltage-to-current converter (1) and the output of the device (6). A balancing capacitor (7) is connected between the output of the device (6) and the output of the non-inverting voltage amplifier (5).

EFFECT: extending the operating frequency range without deterioration of voltage gain.

2 cl, 4 dwg

Description

The invention relates to the field of radio engineering and communication and can be used as a device for amplifying analog RF and microwave signals, in the structure of analog microcircuits of various functional purposes (for example, broadband and selective amplifiers of the RF and microwave ranges implemented by new and promising technologies).

In modern microelectronics, classical transistor amplifiers (TUs) are widely used according to the scheme with a common base [1-4] and with a common emitter [5-19] with a resistive load included in the collector circuit of the output transistor [1-19].

The closest in technical essence to the claimed device is the technical specifications of FIG. 1 according to patent US 7.233.209, fig. 4. It contains an input voltage-current converter 1 (for example, a circuit with a common emitter), the input of which is connected to a signal source 2, and the current output is connected to the bus of the power source 3 through a collector load resistor 4, a non-inverting voltage amplifier 5, the input of which is connected with the current output of the input voltage-current converter 1 and the output of the device 6.

A significant drawback of the known TU, the architecture of which is also present in many other TUs [6-19], is that it has insufficiently high values of the upper cutoff frequency (f _in ). This is due to the negative effect on f _{in the} parasitic capacitance on the substrate (C _p ) and collector-base capacitance (C _kb ) of the output transistor of the input voltage-current converter 1, as well as the effect on f _{in the} capacitive component of the load. Large numerical values of C _p and C _kb for technological processes having, for example, increased radiation resistance, are one of the main factors determining the frequency range of TU-based broadband amplifiers, FIG. one.

The main objective of the invention is to expand the range of operating frequencies of the TU (increase f _in ) without deterioration of the voltage gain.

The problem is solved in that in the transistor amplifier of FIG. 1, containing the input voltage-current converter 1, the input of which is connected to the signal source 2, and the current output is connected to the bus of the power source 3 through a collector load resistor 4, a non-inverting voltage amplifier 5, the input of which is connected to the current output of the voltage-current input converter 1 and the output of the device 6, new elements and connections are provided - between the output of the device 6 and the output of the non-inverting voltage amplifier 5, a correction capacitor 7 is included.

A prototype amplifier circuit is shown in FIG. 1. In FIG. 2 presents a diagram of the inventive device in accordance with paragraph 1 and paragraph 2 of the claims.

In FIG. 3 presents a diagram of the inventive device, FIG. 2, in the environment of PSpice on models of integrated transistors of OJSC NPP Pulsar with specific implementation of its main functional units.

In FIG. 4 shows the amplitude-frequency characteristic of the voltage gain TU; FIG. 3, at different values of the capacitance of the correction capacitor C _k (capacitor 7 in the notation of FIG. 2). From these graphs it follows that the range of operating frequencies of the claimed specifications extends more than 7 times.

The transistor amplifier with an extended frequency range, FIG. 2, contains an input voltage-current converter 1, the input of which is connected to a signal source 2, and the current output is connected to the bus of the power source 3 through a collector load resistor 4, a non-inverting voltage amplifier 5, the input of which is connected to the current output of the voltage input converter current 1 and the output of the device 6. Between the output of the device 6 and the output of the non-inverting voltage amplifier 5, a correction capacitor 7 is included. The stray capacitor 8 in the circuit, FIG. 2, models the effect on its operation of the output capacitance of the input voltage-current converter 1, the input capacitance of a non-inverting voltage amplifier 5 and the equivalent load capacitance connected to the output of the device 6.

For FIG. 2, in accordance with paragraph 2 of the claims, the numerical values of the voltage transfer coefficient of the non-inverting voltage amplifier 5 are greater than unity.

Consider the operation of the technical specifications, FIG. 2.

In the high-frequency region, the amplitude-frequency characteristic of the technical specifications, FIG. 2, the parasitic capacitor 8 begins to influence in the output circuit of the device 6. Moreover, for the circuit, FIG. 2, the following Kirchhoff equations are valid:

,

- комплексы токов через конденсаторы 8 и 7;Where

,

- complexes of currents through capacitors 8 and 7;

- комплекс напряжения на выходе устройства 6;

- voltage complex at the output of device 6;

- комплексное сопротивление паразитного конденсатора 8 на частоте сигнала ω;

- the complex resistance of the parasitic capacitor 8 at the signal frequency ω;

- комплексное сопротивление корректирующего конденсатора 7 на частоте сигнала ω;

- the complex resistance of the correction capacitor 7 at the signal frequency ω;

K _y - voltage gain of a non-inverting voltage amplifier 5.

создает в корректирующем конденсаторе 7 комплекс тока

(2). Поэтому в выходной цепи устройства 6 обеспечивается взаимная компенсация токов

и

и, следовательно, взаимная компенсация влияния емкостей конденсаторов 7 и 8 на верхнюю граничную частоту f_в устройства. При этом необходимо выполнить условие:Voltage

creates a current complex in the correction capacitor 7

(2). Therefore, in the output circuit of the device 6 provides mutual compensation of currents

and

and, therefore, the mutual compensation of the influence of the capacitors of the capacitors 7 and 8 on the upper cutoff frequency f _{in the} device. In this case, it is necessary to fulfill the condition:

where K _y > 1.

Ultimately, when relation (3) is fulfilled, the operating frequency range of the technical specifications, FIG. 2, expanding. This conclusion is confirmed by the results of computer simulation, FIG. four.

Thus, the claimed circuit design of a transistor amplifier is characterized by a wider range of operating frequencies.

Information sources

1. Patent US 6.563.368

2. US Patent 6,825,723 fig. 1, fig. 3, fig. four

3. US Patent 5,914,639 fig. one

4. Patent US 7.042.295 fig. 3a, fig. 3b

5. Patent US 7.233.209 fig. four

6. US patent 6.427.067 fig. one

7. US Pat. No. 6,486,739 fig. one

8. US Patent 6,424,225 fig. 1, fig. 5

9. US Patent 6,417,735 fig. one

10. U.S. Patent 6,414,553 fig. one

11. US Patent 6,392,492 fig. one

12. US Patent 6,333,677 fig. 3

13. U.S. Patent 6.114.912 fig. four

14. U.S. Patent 6,359,516 fig. one

15. U.S. Patent 6.191.656 fig. 2

16. US Patent 6,476,668

17. US patent 6.747.516

18. US patent 6.441.689

19. US Patent 6.005.441

Claims (2)

1. A transistor amplifier with an extended frequency range, containing an input voltage-current converter (1), the input of which is connected to a signal source (2), and the current output is connected to the power supply bus (3) through a collector load resistor (4), a non-inverting amplifier voltage (5), the input of which is connected to the current output of the input voltage-current converter (1) and the output of the device (6), characterized in that between the output of the device (6) and the output of the non-inverting voltage amplifier (5), a correction condens ator (7). 2. A transistor amplifier with an extended frequency range according to claim 1, characterized in that the voltage transfer coefficient of the non-inverting voltage amplifier (5) is greater than unity.

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