A warm-up attenuator and a design method thereof

Abstract

The application discloses a temperature compensation attenuator and a design method thereof, relates to an attenuator device, and belongs to the field of radio frequency and microwave, wherein the temperature compensation attenuator comprises a temperature compensation driving module and an attenuation structure. The temperature compensation driving module adjusts the attenuation of the attenuation structure circuit according to a temperature compensation circuit and a differential network control voltage. The attenuation structure circuit is connected between an input port and an output port, and realizes the circuit attenuation compensation function. The temperature compensation attenuator can compensate the gain variation of active devices caused by temperature change in the microwave / radio frequency channel, has a wide working frequency range, and is suitable for a large attenuation compensation range.

Description

Technical Field

[0001] This invention belongs to the field of radio frequency microwave attenuator devices in microelectronics and solid-state electronics, and specifically relates to a temperature-compensated attenuator and its design method. Background Technology

[0002] Temperature-compensated attenuators, as control elements in microwave / RF channels, control signal amplitude and compensate amplifier gain for temperature variations. They have requirements regarding operating bandwidth, insertion loss, response speed, and dynamic range of attenuation. Common temperature compensation methods include: 1. Operational amplifier control voltage compensation: This method uses closed-loop feedback from the output sampling signal to compensate for input gain; however, it suffers from drawbacks such as temperature offset, long response time, and high cost. 2. Bias circuit compensation: This method relies on the temperature characteristics of diodes and transistors, controlling the transistor's quiescent operating point and bias voltage. This can easily lead to complex amplifier current structures and a narrow operating bandwidth. 3. Thermistor temperature-compensated attenuators: This method uses current to correspondingly change the attenuation; however, it suffers from large device size, small compensation dynamic range, and difficulty in adapting to high-frequency applications. Summary of the Invention

[0003] To address the aforementioned problems, this invention proposes a temperature-compensated attenuator and its design method. The attenuator comprises a temperature-compensated drive module and an attenuation structure circuit. The voltage is controlled by the temperature-compensated drive module, which consists of a temperature-compensated circuit and a differential network, to adjust the continuous change in the attenuation of the attenuation structure circuit. This compensates for the gain variation of active devices in the microwave / RF channel with temperature changes. It possesses advantages such as wide operating bandwidth, large temperature compensation, wide attenuation compensation range, and broad application range.

[0004] A design method for a temperature-compensated attenuator involves designing an attenuation structure circuit between the RF input port and the output port to achieve circuit attenuation compensation; simultaneously, a temperature-compensated drive module is designed to adjust the attenuation amount of the attenuation structure circuit.

[0005] Furthermore, the temperature-compensated driving module includes first to fourth transistors, first to third diodes, and first to sixth resistors; the source of the first transistor is connected to the power supply, the gate is connected to the second transistor, and the drain is grounded through the first resistor; the source of the second transistor is connected to the power supply, and the drain is connected to the sources of the third and fourth transistors respectively; the gate of the third transistor is grounded through the fourth resistor, and the drain is grounded through the second resistor; the gate of the fourth transistor is grounded through the sixth resistor, and the drain is grounded through the third resistor; one end of the fifth resistor is connected to the common terminal of the gate of the fourth transistor and the sixth resistor, and the other end is connected to the power supply; the cathode of the first diode is connected to the power supply, the anode is connected to the cathode of the second diode, the anode of the second diode is connected to the cathode of the third diode, and the anode of the third diode is connected to the common terminal of the gate of the third transistor and the fourth resistor.

[0006] Furthermore, the attenuation structure circuit includes resistors seven to twelfth and transistors five to seven; resistors seven and nine are connected in series, with one end connected to the RF input port and the other end connected to the RF output port; resistors ten and eleven are connected in series, with one end connected to the gate of transistor five and the other end connected to the gate of transistor six; the source and drain of transistor five are connected to the two ends of resistor seven, and the source and drain of transistor six are connected to the two ends of resistor nine; the source of transistor seven is connected to the common terminal of resistors seven and nine, the drain is grounded through resistor eight, and the gate is connected to resistor twelfth.

[0007] Furthermore, the common terminal of the tenth and eleventh resistors is connected to the drain of the third transistor.

[0008] Furthermore, the gate of the seventh transistor is connected to the drain of the fourth transistor through the twelfth resistor.

[0009] A temperature-compensated attenuator, designed using the method described above, is based on gallium arsenide technology.

[0010] Compared with traditional temperature-compensated attenuators, the advantages and beneficial effects of this invention are as follows:

[0011] 1. A temperature-compensated drive module composed of a temperature-compensated circuit and a differential network is used to control the attenuation of the voltage regulation attenuation structure circuit, thereby expanding the voltage regulation range and increasing the compensation range of the attenuation.

[0012] 2. Temperature-compensated attenuators have a wide operating bandwidth, a wide operating temperature range, a large temperature compensation range, and high temperature compensation accuracy, making them widely applicable in microwave / RF systems;

[0013] 3. Designed using gallium arsenide (GaAs) technology, it is easy to integrate with GaAs chips. Attached Figure Description

[0014] The accompanying drawings are provided to further illustrate embodiments of the present invention and form part of this application, but do not constitute a limitation thereof. In the drawings:

[0015] Figure 1 This is a schematic diagram of the temperature-compensated attenuator circuit according to an embodiment of the present invention;

[0016] Figure 2 This is a layout diagram of the temperature-compensated attenuator circuit according to an embodiment of the present invention;

[0017] Figure 3 This is a graph showing the relationship between the input standing wave ratio and frequency of the temperature-compensated attenuator circuit in an embodiment of the present invention.

[0018] Figure 4 This is a graph showing the relationship between the output standing wave ratio and frequency of the temperature-compensated attenuator circuit in an embodiment of the present invention.

[0019] Figure 5 This is a graph showing the relationship between insertion loss and frequency in the temperature-compensated attenuator circuit of this invention. Detailed Implementation

[0020] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0021] This invention discloses a temperature-compensated attenuator circuit and its design method. The temperature-compensated attenuator includes a temperature-compensated driving module and an attenuation structure circuit. The temperature-compensated driving module adjusts the attenuation of the attenuation structure circuit according to the control voltage of the temperature-compensated circuit and the differential network. The attenuation structure circuit is connected between the RF input port and the output port to realize the circuit attenuation compensation function.

[0022] Furthermore, the temperature-compensated drive module consists of a temperature-compensated circuit and a differential network. The temperature-compensated circuit is formed by diodes and resistors with temperature characteristics. A mirror current source provides a suitable bias current to the differential circuit. The gate of the transistor in the differential network is connected to the temperature-compensated circuit composed of diodes and resistors with temperature characteristics, thus expanding the range of control voltage variation and increasing the temperature attenuation compensation.

[0023] Furthermore, the attenuation structure circuit is a distributed attenuator composed of several resistors and transistors. Two series transistors and one parallel transistor form the main path between the input port and the output port. The series transistor has a parallel resistor between its drain and source, and its gate series resistor is connected to the inverting input of the temperature-compensated drive module comparator output. The parallel transistor has its source series resistor connected to ground, and its gate series resistor is connected to the non-inverting input of the temperature-compensated drive module comparator output.

[0024] Furthermore, the temperature-compensated attenuator proposed in this invention is designed based on gallium arsenide technology.

[0025] The temperature-compensated attenuator in this embodiment is designed using gallium arsenide technology, and its circuit schematic is shown below. Figure 1 As shown, the entire circuit includes a temperature-compensated drive module and an attenuation structure circuit. The temperature-compensated drive module includes a current mirror source composed of transistors T1 and T2, and a differential network composed of T3 and T4. The power supply is connected to the current mirror source; one end of the current mirror source is connected to ground via resistor R1, and the other end is connected to an active load consisting of the differential network and resistors R2 and R3. Simultaneously, the gate of T3 is connected to the power supply via temperature-sensitive diodes D1-D3, and the gate of T4 is connected to the power supply via resistor R5. The gate of T3 is connected to ground via resistor R4, and the gate of T4 is connected to ground via resistor R6.

[0026] The attenuation structure circuit includes a distributed temperature-compensated attenuator composed of several resistors and three transistors; two series-connected transistors SW1~SW2 and a parallel-connected transistor SW3 form the main path between the RF input port and the output port. A resistor R7 is connected in parallel between the source and drain of transistor SW1, and a resistor R9 is connected in parallel between the source and drain of transistor SW2. The gates of SW1 and SW2 are connected to the output of temperature-compensated driver T3 after being connected in series with resistors R10 and R11. The drain of transistor SW3 is connected to ground after being connected to resistor R8, and the gate of SW3 is connected to the output of temperature-compensated driver module T4 after being connected in series with resistor R12. The source of SW3 is connected between resistors R7 and R9.

[0027] The temperature-compensated drive module, composed of a temperature-compensated circuit and a differential network, can control the voltage in response to temperature changes. The attenuation structure circuit is also voltage-controlled, achieving temperature-compensated attenuation. A temperature-compensated attenuator is designed on a gallium arsenide substrate, with an integrated chip layout as shown below. Figure 2 As shown. The chip operates at a frequency of DC-45GHz, with a temperature compensation range of -55℃ to +125℃. Figure 3 This demonstrates the relationship between the chip's input standing wave ratio and frequency. Figure 4 This demonstrates the relationship between output standing wave ratio (VSWR) and frequency; within the operating frequency range, the input and output VSWR are less than 2. For example... Figure 5 The relationship between the insertion loss and frequency of the circuit at different temperatures was demonstrated. At the center point of 22.5 GHz, the insertion loss was -9.5 dB at -55℃ and -1.4 dB at +125℃, with a compensation of 8.1 dB over the entire temperature range, demonstrating its advantages of wide dynamic range of attenuation and large temperature compensation.

[0028] It should be noted that the above description of the embodiments is only for the purpose of helping to understand the method and core idea of ​​this application. For those skilled in the art, several improvements and modifications can be made to this application without departing from the principle of this application, and these improvements and modifications are also within the protection scope of the claims of this application.

Claims

1. A design method for a temperature-compensated attenuator, characterized in that, An attenuation structure circuit is designed between the RF input port and the output port to realize the circuit attenuation compensation function; at the same time, a temperature compensation drive module is designed to adjust the attenuation of the attenuation structure circuit. The temperature compensation drive module includes first to fourth transistors, first to third diodes, and first to sixth resistors; The source of the first transistor is connected to the power supply, the gate is connected to the second transistor, and the drain is grounded through the first resistor; the source of the second transistor is connected to the power supply, and the drain is connected to the source of the third and fourth transistors respectively. The gate of the third transistor is grounded through the fourth resistor, and the drain is grounded through the second resistor; the gate of the fourth transistor is grounded through the sixth resistor, and the drain is grounded through the third resistor; one end of the fifth resistor is connected to the common terminal of the gate of the fourth transistor and the sixth resistor, and the other end is connected to the power supply; the cathode of the first diode is connected to the power supply, the anode is connected to the cathode of the second diode, the anode of the second diode is connected to the cathode of the third diode, and the anode of the third diode is connected to the common terminal of the gate of the third transistor and the fourth resistor.

2. The design method of a temperature-compensated attenuator according to claim 1, characterized in that, The attenuation structure circuit includes resistors seven to twelfth and transistors five to seven; resistors seven and nine are connected in series, with one end connected to the RF input port and the other end connected to the RF output port. The tenth and eleventh resistors are connected in series, with one end connected to the gate of the fifth transistor and the other end connected to the gate of the sixth transistor. The source and drain of the fifth transistor are connected to the two ends of the seventh resistor, and the source and drain of the sixth transistor are connected to the two ends of the ninth resistor. The source of the seventh transistor is connected to the common terminal of the seventh and ninth resistors, the drain is grounded through the eighth resistor, and the gate is connected to the twelfth resistor.

3. The design method of a temperature-compensated attenuator according to claim 2, characterized in that, The common terminal of the tenth and eleventh resistors is connected to the drain of the third transistor.

4. The design method of a temperature-compensated attenuator according to claim 2, characterized in that, The gate of the seventh transistor is connected to the drain of the fourth transistor through the twelfth resistor.

5. A temperature-compensated attenuator, characterized in that, It is designed using the method described in any one of claims 1 to 4.

6. A temperature-compensated attenuator as described in claim 5, characterized in that, Design based on gallium arsenide process.

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