A single voltage controlled voltage controlled attenuator and chip

Abstract

The present invention belongs to the technical field of voltage-controlled attenuators, and in particular to a single-voltage-controlled voltage-controlled attenuator and a chip. The voltage-controlled attenuator includes a single positive voltage control voltage, a resistor R D , a plurality of Π-type attenuation units connected in series on the RF main line, wherein the impedance matching is satisfied inside the Π-type attenuation unit; the control voltage is passed through the resistor R D The Π-type attenuation unit includes a FET transistor located on the RF main line as a switch, and the source and gate ends of the FET transistor are respectively connected to a first variable resistor component and a second variable resistor component, and the first variable resistor component and the second variable resistor component satisfy that the dynamic resistance is linear with the control voltage. The present invention can provide a single positive voltage controlled voltage-controlled attenuator, which has a simple system structure, is not easily affected by temperature, and has small fluctuations in the RF channel gain.

Description

Technical Field

[0001] The invention belongs to the technical field of voltage-controlled attenuators, and in particular relates to a single-voltage-controlled voltage-controlled attenuator and a chip. Background Art

[0002] In recent years, MMIC technology has developed rapidly and is widely used in active phased array radar components. In active phased array radar, T / R components are its basic components. In order to achieve precise amplitude and phase control of the transmitted and received signals and improve the system's ability to resolve targets, an adjustable attenuator with a large attenuation range, wide frequency coverage, high attenuation accuracy, and good linearity is required. In traditional design schemes, voltage-controlled attenuators have the following main problems: (1) The working conditions are complex, and the system needs to provide two or more voltages, which makes it impossible to achieve single positive voltage control, increasing the complexity of the system; (2) The attenuation is easily affected by the ambient temperature, resulting in large fluctuations in channel gain. In order to solve the above problems, reduce system complexity, improve system integration, and perform temperature compensation design at the same time, reduce the fluctuation of channel gain, and improve consistency, a single voltage-controlled voltage-controlled attenuator is now urgently needed. Summary of the invention

[0003] In view of the above problems, the present invention

[0004] A single voltage controlled voltage controlled attenuator, comprising a single positive voltage control voltage, a resistor R D , a plurality of Π-type attenuation units connected in series on the RF main line, wherein the Π-type attenuation units satisfy impedance matching inside;

[0005] The control voltage is passed through the resistor R D Connected to the RF main line;

[0006] The Π-type attenuation unit includes a FET transistor located on the RF main line as a switch, the source and gate of the FET transistor are respectively connected to a first variable resistance component and a second variable resistance component, and the first variable resistance component and the second variable resistance component satisfy that the dynamic resistance is linear with the control voltage.

[0007] Optionally, the first variable resistance component includes a first Schottky diode D A and resistor R A , the first Schottky diode D A With resistor R A Forward series grounding.

[0008] Optionally, the second variable resistance component includes a second Schottky diode D B , the second Schottky diode D B Ground.

[0009] Optionally, the source and drain terminals of the FET transistor are connected in parallel with a resistor R C .

[0010] Optionally, the gate series resistor R of the FET transistor B To the ground.

[0011] Optionally, there are two Π-type attenuation units, and the control voltage passes through the resistor R D The connection point with the RF main line is mirror-symmetrical.

[0012] Optional,

[0013] The resistor R D and resistor R A It is a temperature sensitive resistor.

[0014] A chip integrates the voltage-controlled attenuator mentioned above.

[0015] Beneficial Effects

[0016] (1) Use single voltage power supply to reduce system complexity, adopt temperature compensation design to reduce the impact of temperature on attenuation, reduce channel gain fluctuations, and improve consistency.

[0017] (2) Parallel resistance R between source and drain of FET transistor C , thereby reducing the sensitivity of the maximum attenuation to the control voltage.

[0018] (3) Gate series resistance R of FET transistor B To the ground, it can prevent high-frequency signal leakage.

[0019] (4) By adjusting the resistor R D and resistor R A The resistance value is used to control the attenuation change of the voltage-controlled attenuator at all temperatures, thereby further realizing the temperature compensation function of the voltage-controlled attenuator.

[0020] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 It shows a circuit structure diagram of a voltage-controlled attenuator according to an embodiment of the present invention;

[0023] Figure 2 The figure shows a structural diagram of an equivalent attenuation circuit according to an embodiment of the present invention. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] The present invention discloses a single voltage controlled voltage controlled attenuator, the voltage controlled attenuator comprising a single positive voltage control voltage, a resistor R D , a plurality of Π-type attenuation units connected in series on the RF main line, wherein the Π-type attenuation units satisfy impedance matching inside;

[0026] The control voltage is passed through the resistor R D Connected to the RF main line;

[0027] The Π-type attenuation unit includes a FET transistor located on the RF main line as a switch, the source and gate of the FET transistor are respectively connected to a first variable resistance component and a second variable resistance component, and the first variable resistance component and the second variable resistance component satisfy that the dynamic resistance is linear with the control voltage.

[0028] Specifically, in this embodiment, the voltage floating technology is adopted to change the traditional negative voltage controlled attenuator into a positive voltage controlled attenuator. The control voltage is connected to the series resistor R D Connected to the RF main line, the single positive voltage controls the attenuation to change linearly. As the control voltage increases, the reverse voltage difference between the gate and the source in the Π-type attenuation unit increases, and the equivalent resistance increases. At the same time, the first variable resistor R A The conduction current increases and the resistance value decreases, thereby realizing a linear increase in the attenuation of the voltage-controlled attenuation circuit. The FET transistor, the first variable resistor component, and the second variable resistor component form a Π-type attenuator structure, which increases the attenuation at low temperatures and decreases at high temperatures, thereby realizing the temperature compensation function of the voltage-controlled attenuator. Due to the temperature compensation function, the gain fluctuation of the RF channel will also be reduced.

[0029] Furthermore, the first variable resistor component includes a first Schottky diode D A and resistor R A, the first Schottky diode D A With resistor R A The second variable resistance component includes a second Schottky diode D B , the second Schottky diode D B Ground. Specifically, the appropriate series resistor R A The bias current can be passed through the series FET transistor and the parallel first Schottky diode D A , the second Schottky diode D B The second Schottky diode D is connected in parallel to the RF main line. B A Π-type attenuation circuit is formed between the FET transistor, the first Schottky diode and the second Schottky diode.

[0030] When the ambient temperature rises, D A and D B The equivalent resistance value of the RF main circuit is reduced, which reduces the voltage difference of the FET transistor, reduces the series equivalent resistance, and thus reduces the attenuation of the voltage-controlled attenuator at high temperatures. When the ambient temperature decreases, D A and D B The equivalent resistance value of the FET increases, which leads to an increase in the voltage division on the RF line, which leads to an increase in the reverse voltage difference of the FET transistor, thereby increasing the attenuation of the voltage-controlled attenuator at low temperatures. The temperature compensation function of the voltage-controlled attenuator is realized.

[0031] Furthermore, the source and drain terminals of the FET transistor are connected in parallel with a resistor R C Specifically, in the maximum attenuation state, the equivalent resistance of the FET transistor changes significantly under high and low temperature conditions. C The equivalent resistance of the FET transistor is relatively small, so the resistance of the FET transistor can be almost ignored, preventing the deterioration of the attenuation of the voltage-controlled attenuator under high and low temperature conditions, and effectively reducing the sensitivity of the maximum attenuation to the control voltage.

[0032] Furthermore, the gate series resistance R of the FET transistor B Specifically, the gate series resistor R B , which can improve the isolation between the gate and the source and drain and prevent high-frequency signal leakage.

[0033] Furthermore, there are two Π-type attenuation units, and the control voltage passes through the resistor R D The connection point with the RF main line is mirror-symmetrical. Figure 1As shown, two Π-type attenuation units are connected in series, which can attenuate the RF signal multiple times, realize temperature compensation multiple times, and further reduce the fluctuation of RF channel gain. Each Π-type attenuation unit has n first Schottky diodes D A , respectively, the first Schottky diode D A1 、The first Schottky diode D A2 ...the first Schottky diode D An , where the first Schottky diode D A1 、The first Schottky diode D A2 ...the first Schottky diode D An are connected in parallel, and each first Schottky diode is connected in series with a resistor R A Grounded; each Π-type attenuation unit has m second Schottky diodes D B , respectively named D B1 , D B2 ...D Bm , D B1 , D B2 ...D Bm Connect in parallel.

[0034] like Figure 2 As shown, the resistance of resistor r1 is the equivalent resistance of FET transistor S1 and R C1 The equivalent resistance of S1 in the maximum attenuation state changes significantly under high and low temperature conditions, because the equivalent resistance of RC1 is smaller than that of S1 at this time, so r1 is mainly composed of R C1 The resistance value of resistor r3 is determined by the resistance of Schottky diode D, which prevents the chip from deteriorating in high and low temperature conditions. The equivalent Π-type attenuation circuit 2 is similar, ensuring the stability of the maximum attenuation value of the chip under full temperature conditions. A The equivalent resistance of R A The resistance of the series resistor R4 is the Schottky diode D B The resistance value of the equivalent resistor.

[0035] Furthermore, the resistor R D and resistor R A It is a temperature sensitive resistor.

[0036] Specifically, by adjusting the resistor R D and resistor R A To control the attenuation change of the voltage-controlled attenuator under full temperature, further realize the temperature compensation function of the voltage-controlled attenuator. D For example: When R DWhen using a thermistor with a positive temperature coefficient, the resistance value increases at high temperatures, resulting in a decrease in the voltage divider on the RF line, which reduces the degree of openness of the diode on the parallel branch, increases the parallel equivalent resistance, and at the same time reduces the reverse voltage difference of the FET transistor, and reduces the series equivalent resistance, thereby further reducing the attenuation of the voltage-controlled attenuator at high temperatures; the resistance value decreases at low temperatures, resulting in an increase in the voltage divider on the RF main line, which increases the degree of openness of the diode on the parallel branch, reduces the parallel equivalent resistance, and at the same time increases the reverse voltage difference of the FET transistor, and increases the series equivalent resistance, thereby further reducing the attenuation of the voltage-controlled attenuator at high temperatures. Thermistors with negative temperature coefficients have the opposite effect and will not be described in detail. Through the resistor R A and R D Different combinations can meet various temperature compensation requirements of high and low temperatures.

[0037] Another embodiment of the present invention further discloses a chip, wherein the chip integrates the voltage-controlled attenuator described in the above embodiment.

[0038] Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent substitutions for some of the technical features therein; and these modifications or substitutions do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A single voltage controlled voltage controlled attenuator, It is characterized in that The voltage-controlled attenuator includes a single positive voltage control voltage, a resistor R D , a plurality of Π-type attenuation units connected in series on the RF main line, wherein the Π-type attenuation units satisfy impedance matching inside; The control voltage is passed through the resistor R D Connected to the RF main line, the resistor R D is a temperature sensitive resistor; The Π-type attenuation unit has two components, and the control voltage is passed through the resistor R D The connection point with the RF main line is mirror-symmetric; the Π-type attenuation unit includes a FET transistor located on the RF main line as a switch, and the source and drain of the FET transistor are respectively connected to a first variable resistor component and a second variable resistor component, and the first variable resistor component and the second variable resistor component satisfy that the dynamic resistance is linear with the control voltage.

2. A single voltage controlled voltage controlled attenuator according to claim 1, It is characterized in that The first variable resistance component includes a first Schottky diode D A and resistor R A , the first Schottky diode D A With resistor R A Forward series grounding.

3. A single voltage controlled voltage controlled attenuator according to claim 1, It is characterized in that The second variable resistance component includes a second Schottky diode D B , the second Schottky diode D B Ground.

4. A single voltage controlled voltage controlled attenuator according to claim 1, It is characterized in that The source and drain terminals of the FET transistor are connected in parallel with a resistor R C .

5. The single voltage controlled voltage controlled attenuator according to claim 1, It is characterized in that The gate series resistance R of the FET transistor B To the ground.

6. A single voltage controlled voltage controlled attenuator according to claim 2, It is characterized in that The resistor R A It is a temperature sensitive resistor.

7. A chip, It is characterized in that The voltage-controlled attenuator according to any one of claims 1 to 6 is integrated.

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