Voltage-controlled group delay adjustment module, digital control adjustment circuit and radio frequency microwave circuit

Abstract

The present invention provides a voltage-controlled group delay adjustment module, a digital control adjustment circuit and a radio frequency microwave circuit, including: a filter, receiving an input signal, for selecting a working frequency band and filtering out interference signals; a negative group delay unit, connected to the output end of the filter, for transmitting a signal and adjusting the negative group delay characteristics of the signal; a first varactor diode, connected to the main path of the negative group delay unit, for adjusting the group delay characteristics based on the reverse bias of the first varactor diode; a transformer, a primary coil receiving a first tuning voltage, a secondary coil connected to both ends of the first varactor diode, for voltage-changing and adjusting the first tuning voltage and applying it to both ends of the first varactor diode to change the reverse bias of the first varactor diode. The present invention effectively adjusts the group delay characteristics of the circuit through voltage regulation, and is used for group delay characteristic compensation of filters, amplifiers and even radio frequency microwave circuits, and also realizes more accurate digital control regulation by configuring a peripheral DAC circuit.

Description

Technical Field

[0001] The present invention relates to the field of integrated circuit design, and in particular to a voltage-controlled group delay adjustment module, a digital control adjustment circuit and a radio frequency microwave circuit. Background Art

[0002] The concept of group delay was first proposed by Americans in the 1930s. It is used to measure the phase distortion of equipment. It is the transmission time taken by the signal to pass through the equipment at different frequencies. It is a derivative characteristic of the equipment phase characteristic and is closely related to the frequency. In the process of signal transmission, to measure the quality of a transmission system, we need to analyze the frequency characteristics and time domain characteristics of the system at the same time. A good signal transmission system should not only have good consistency of amplitude-frequency characteristics, but also good consistency of phase-frequency characteristics. The concept of group delay is used to describe the flatness of the system phase-frequency characteristics.

[0003] In recent years, with the improvement of theories such as communication radar, space detection, satellite navigation, and millimeter wave communication measurement, as well as the continuous improvement of software and hardware levels, the requirements for the transmission capacity and channel transmission characteristics of communication systems have become increasingly higher. Compared with amplitude, phase can carry more useful information in the process of signal transmission and has higher stability. Group delay is a very important parameter used to represent the phase linearity of the signal in the transmission system, and it is particularly important. For example, in various radar receiving systems and in the transceiver components of phased array technology, it is required that each channel has consistent group delay characteristics. However, due to the limitations of the processing technology, assembly consistency, and slight physical differences of the actual devices, the group delay characteristics of the circuits will be different. In order to achieve more efficient group delay characteristic compensation, different from the existing group delay compensation circuit designed for a single curve and the complex and costly digital domain precision compensation, a more universal group delay adjustment circuit is needed to achieve compensation for circuits with different group delay characteristics. Summary of the invention

[0004] In view of the above-mentioned shortcomings of the prior art, an object of the present invention is to provide a voltage-controlled group delay adjustment module, a digital control adjustment circuit and a radio frequency microwave circuit to solve the problem of poor consistency of group delay characteristics in the prior art.

[0005] In order to achieve the above-mentioned object and other related objects, the present invention provides a voltage-controlled group delay adjustment module, and the voltage-controlled group delay adjustment module at least includes:

[0006] A filter receives an input signal, is used to select an operating frequency band and filter out interference signals;

[0007] A negative group delay unit, connected to the output end of the filter, for transmitting a signal and adjusting a negative group delay characteristic of the signal;

[0008] A first varactor diode is connected to the main path of the negative group delay unit, and the group delay characteristic is adjusted based on the reverse bias voltage of the first varactor diode;

[0009] The transformer has a primary coil receiving a first tuning voltage and a secondary coil connected to both ends of the first varactor diode, and is used to perform voltage transformation and regulation on the first tuning voltage and apply it to both ends of the first varactor diode to change the reverse bias voltage of the first varactor diode.

[0010] Optionally, the filter is a low-pass filter, a high-pass filter, a band-pass filter or a direct-pass circuit.

[0011] Optionally, the negative group delay unit includes a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a first resistor, a second resistor, a first inductor, a second inductor and a third inductor;

[0012] One end of the first capacitor is grounded, and the other end is connected to the first end of the first inductor; the second end of the first inductor is connected to the output end of the filter via the first resistor; one end of the second capacitor is connected to the output end of the filter, and the other end is connected to the first end of the second inductor; the second end of the second inductor is connected to one end of the third capacitor; the other end of the third capacitor serves as the output end of the voltage-controlled group delay adjustment module; one end of the second resistor is connected to the output end of the voltage-controlled group delay adjustment module, and the other end is connected to the first end of the third inductor; the second end of the third inductor is grounded via the fourth capacitor.

[0013] More optionally, the voltage-controlled group delay adjustment module also includes a second varactor diode and a third varactor diode; the positive electrode of the second varactor diode is grounded, and the negative electrode is connected to the connection node between the first capacitor and the first inductor; the connection node between the first capacitor and the first inductor receives a second tuning voltage; the positive electrode of the third varactor diode is grounded, and the negative electrode is connected to the connection node between the fourth capacitor and the third inductor; the connection node between the fourth capacitor and the third inductor receives a third tuning voltage.

[0014] More optionally, the voltage-controlled group delay adjustment module also includes a fifth capacitor and a sixth capacitor; the fifth capacitor is connected between the output end of the filter and the input end of the negative group delay unit; the sixth capacitor is connected between the output end of the negative group delay unit and the output end of the voltage-controlled group delay adjustment module.

[0015] More optionally, an anode of the first varactor diode is connected to a connection node between the second capacitor and the second inductor, and a cathode of the first varactor diode is connected to a connection node between the second inductor and the third capacitor.

[0016] More optionally, the voltage-controlled group delay adjustment module further includes a temperature compensation unit, wherein the temperature compensation unit is connected to both ends of the first varactor diode and is used to perform temperature compensation on the group delay characteristics of the voltage-controlled group delay adjustment module.

[0017] More optionally, the temperature compensation unit is a temperature sensitive resistor.

[0018] To achieve the above-mentioned object and other related objects, the present invention provides a digital control regulating circuit, which at least includes: a DAC module and the above-mentioned voltage-controlled group delay regulating module;

[0019] The output end of the DAC module is connected to the voltage-controlled group delay adjustment module to provide a tuning voltage for the voltage-controlled group delay adjustment module.

[0020] To achieve the above-mentioned object and other related objects, the present invention provides a radio frequency microwave circuit, which at least includes: the above-mentioned voltage-controlled group delay adjustment module, and the voltage-controlled group delay adjustment module is connected in series in a signal transmission line.

[0021] As described above, the voltage-controlled group delay adjustment module, digital control adjustment circuit and radio frequency microwave circuit of the present invention have the following beneficial effects:

[0022] The present invention controls the internal varactor device through an external tuning voltage to adjust the group delay characteristics of the circuit. At the same time, a more detailed and accurate adjustment function is achieved by adjusting the main circuit and the branch circuit separately, so that the circuit has a wider range of practical application value. In combination with the temperature compensation device, the group delay characteristics changes caused by the change of ambient temperature or the temperature rise effect of the circuit itself during the actual circuit operation are compensated to a certain extent, so that the circuit has more stable working characteristics. In combination with the peripheral DAC circuit, the present invention can be further configured as a digital control adjustment circuit. At the same time, the present invention can also be cascaded in various radio frequency microwave circuits or systems as a fixed group delay characteristics compensation circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 Shown is a schematic diagram of the structure of the voltage-controlled group delay adjustment module of the present invention.

[0024] Figure 2 Shown is a schematic diagram of the packaging and pin distribution of the voltage-controlled group delay adjustment module of the present invention.

[0025] Component number description

[0026] 1 Voltage-controlled group delay adjustment module

[0027] 11 Filter

[0028] 12 Negative Group Delay Unit DETAILED DESCRIPTION

[0029] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

[0030] See also Figure 1-2 It should be noted that the illustrations provided in this embodiment are only used to illustrate the basic concept of the present invention in a schematic manner, and the drawings only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0031] Embodiment 1

[0032] like Figure 1 As shown, this embodiment provides a voltage-controlled group delay adjustment module 1, and the voltage-controlled group delay adjustment module 1 includes:

[0033] The filter 11, the negative group delay unit 12, the first varactor diode VD1 and the transformer T1.

[0034] like Figure 1 As shown, the filter 11 receives an input signal IN and is used to select a working frequency band and filter out interference signals.

[0035] Specifically, the filter 11 includes but is not limited to a low-pass filter, a high-pass filter, a band-pass filter or a direct-pass circuit, and the corresponding application frequency band can be selected according to actual signal characteristics and requirements. In this embodiment, the filter 11 adopts a low-pass filter.

[0036] like Figure 1 As shown, the negative group delay unit 12 is connected to the output end of the filter 11, and is used to transmit the signal and adjust the negative group delay characteristics of the signal.

[0037] Specifically, in this embodiment, the negative group delay unit 12 includes a first capacitor C1, a second capacitor C2, a third capacitor C3, a fourth capacitor C4, a first resistor R1, a second resistor R2, a first inductor L1, a second inductor L2 and a third inductor L3. One end of the first capacitor C1 is grounded, and the other end is connected to the first end of the first inductor L1. The second end of the first inductor L1 is connected to the output end of the filter 11 via the first resistor R1. One end of the second capacitor C2 is connected to the output end of the filter 11, and the other end is connected to the first end of the second inductor L2. The second end of the second inductor L2 is connected to one end of the third capacitor C3. The other end of the third capacitor C3 serves as the output end of the voltage-controlled group delay adjustment module 12. One end of the second resistor R2 is connected to the output end of the voltage-controlled group delay adjustment module 12, and the other end is connected to the first end of the third inductor L3. The second end of the third inductor L3 is grounded via the fourth capacitor C4.

[0038] It should be noted that the negative group delay unit 12 is a π-type topology structure, and the second capacitor C2, the second inductor L2 and the third capacitor C3 constitute the main path of the negative group delay unit 12. In actual use, the corresponding structure can be designed based on capacitors, inductors and resistors according to the specific application frequency band; further, any circuit structure that can be used for negative group delay adjustment is applicable, and is not limited to the π-type topology structure listed in this embodiment.

[0039] like Figure 1 As shown, as another implementation of the present invention, the voltage-controlled group delay adjustment module 1 also includes a fifth capacitor C5 and a sixth capacitor C6. The fifth capacitor C5 is connected between the output end of the filter 11 and the input end of the negative group delay unit 12; that is, one end of the fifth capacitor C5 is connected to the output end of the filter 11, and the other end is connected to the connection node of the first resistor R1 and the second capacitor C2. The sixth capacitor C6 is connected between the output end of the negative group delay unit 12 and the output end of the voltage-controlled group delay adjustment module 1; that is, one end of the sixth capacitor C6 is connected to the connection node of the third capacitor C3 and the second resistor R2, and the other end serves as the output end of the voltage-controlled group delay adjustment module 1.

[0040] like Figure 1 As shown, the first varactor diode VD1 is connected to the main path of the negative group delay unit 12, and the group delay characteristic is adjusted based on the reverse bias voltage of the first varactor diode VD1.

[0041] Specifically, in this embodiment, the positive electrode of the first varactor diode VD1 is connected to the connection node between the second capacitor C2 and the second inductor L2, and the negative electrode is connected to the connection node between the second inductor L2 and the third capacitor C3; that is, the first varactor diode VD1 is connected in parallel to both ends of the second inductor L2. In actual use, the first varactor diode VD1 can be connected to other positions of the main path in the negative group delay unit 12 as needed.

[0042] like Figure 1 As shown, the primary coil of the transformer T1 receives the first tuning voltage Vt1, and the secondary coil is connected to both ends of the first varactor diode VD1, for transforming and regulating the first tuning voltage Vt1 and applying it to both ends of the first varactor diode VD1 to change the reverse bias voltage of the first varactor diode VD1.

[0043] Specifically, the transformer T1 includes a primary coil and a secondary coil. One end of the primary coil is connected to the first tuning voltage Vt1, and the other end is grounded; it should be noted that the potential of the ground end of the primary coil and the ground end of the negative group delay unit 12 can be the same or different, and can be set according to actual needs, which will not be described here. One end of the secondary coil is connected to the positive electrode of the first varactor diode VD1, and the other end is connected to the negative electrode of the first varactor diode VD1. The ratio of the primary coil to the secondary coil is 1:N, where N is a natural number greater than zero.

[0044] Specifically, the first tuning voltage Vt1 can adjust the capacitance of the main circuit varactor diode in a wider range through the transformer T1, and has a wider practical application value.

[0045] like Figure 1 As shown, as another implementation of the present invention, the voltage-controlled group delay adjustment module 1 also includes a second varactor diode VD2 and a third varactor diode VD3. The positive electrode of the second varactor diode VD2 is grounded (the grounding end of the negative group delay unit 12), and the negative electrode is connected to the connection node of the first capacitor C1 and the first inductor L1. The connection node of the first capacitor C1 and the first inductor L1 receives the second tuning voltage Vt2. The positive electrode of the third varactor diode VD3 is grounded (the grounding end of the negative group delay unit 12), and the negative electrode is connected to the connection node of the fourth capacitor C4 and the third inductor L3. The connection node of the fourth capacitor C4 and the third inductor L3 receives the third tuning voltage Vt3. Among them, the second tuning voltage Vt2 and the third tuning voltage Vt3 are used to finely adjust the negative group delay characteristics, with high precision and a wide range of applications.

[0046] like Figure 1As shown, as another implementation of the present invention, the voltage-controlled group delay adjustment module 1 further includes a temperature compensation unit, which is connected to both ends of the first varactor diode VD1 and is used to perform temperature compensation on the group delay characteristics of the voltage-controlled group delay adjustment module 1. As an example, the temperature compensation unit is a temperature-sensitive resistor RC1, which senses and dynamically adjusts the operating temperature so that the voltage-controlled group delay adjustment module 1 maintains stable circuit characteristics under different ambient temperatures.

[0047] like Figure 2 The figure shows the packaging and pin distribution diagram of the voltage-controlled group delay adjustment module 1. The voltage-controlled group delay adjustment module 1 can be integrated into a chip to form a single chip. The pin positions can be set as needed and are not limited to those listed in this embodiment.

[0048] The present invention adjusts the circuit group delay characteristics by controlling the internal varactor device through an external tuning voltage. At the same time, a more detailed and accurate adjustment function is achieved by adjusting the main circuit and the branch circuit separately. The temperature compensation device is combined to compensate to a certain extent for the change of group delay characteristics caused by the change of ambient temperature or the temperature rise effect of the circuit itself during the actual operation process, so that the circuit has more stable working characteristics.

[0049] Embodiment 2

[0050] This embodiment provides a digital control regulating circuit, which includes: a DAC module and the voltage-controlled group delay regulating module 1 of the first embodiment.

[0051] Specifically, the output end of the DAC module is connected to the voltage-controlled group delay adjustment module 1 to provide a tuning voltage for the voltage-controlled group delay adjustment module. The tuning voltage includes at least the first tuning voltage Vt1, and may also include the second tuning voltage Vt2 and the third tuning voltage Vt3, so as to realize digital control of the voltage-controlled group delay adjustment module 1, and further configured as a digital control adjustment circuit.

[0052] Embodiment 3

[0053] This embodiment provides a radio frequency microwave circuit, which includes: the voltage-controlled group delay adjustment module 1 of the first embodiment, and the voltage-controlled group delay adjustment module 1 is connected in series in a signal transmission line.

[0054] It should be noted that any radio frequency microwave circuit structure that requires adjustment of group delay is applicable to the present invention and will not be described in detail here.

[0055] In summary, the present invention provides a voltage-controlled group delay adjustment module, a digital control adjustment circuit and a radio frequency microwave circuit, wherein the voltage-controlled group delay adjustment module includes: a filter for suppressing out-of-band interference; a negative group delay circuit composed of basic resistors, capacitors and inductors adapted to different application frequency bands; a varactor diode as a regulator to adjust the circuit group delay characteristics by adjusting its reverse bias voltage; a temperature compensation resistor to sense external temperature changes and compensate for circuit characteristics working at different ambient temperatures, while compensating for the group delay characteristic offset caused by its own temperature rise effect; a transformer to proportionally expand the range of the tuning voltage, reduce the threshold range of the external control voltage, and adapt to the high reverse bias requirements of the varactor diode to achieve a wider capacitance adjustment range. The present invention controls the internal varactor device through an external tuning voltage to adjust the circuit group delay characteristics, and at the same time, realizes a more detailed and accurate adjustment function through the separate adjustment of the main circuit and the branch circuit, so that the circuit has a wider range of practical application value, and combines the temperature compensation device to compensate for the group delay characteristic changes caused by the ambient temperature change or the temperature rise effect of the actual circuit to a certain extent, so that the circuit has a more stable working characteristic. Combined with the peripheral DAC circuit, the present invention can be further configured as a digital control adjustment circuit. At the same time, the present invention can also be used as a fixed group delay characteristic compensation circuit cascaded in various radio frequency microwave circuits or systems. Therefore, the present invention effectively overcomes various shortcomings in the prior art and has a high industrial utilization value.

[0056] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A voltage-controlled group delay adjustment module, characterized in that: The voltage-controlled group delay adjustment module at least includes: A filter receives an input signal, is used to select an operating frequency band and filter out interference signals; A negative group delay unit is connected to the output end of the filter, and is used to transmit a signal and adjust the negative group delay characteristics of the signal; the negative group delay unit includes a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a first resistor, a second resistor, a first inductor, a second inductor and a third inductor; one end of the first capacitor is grounded, and the other end is connected to the first end of the first inductor; the second end of the first inductor is connected to the output end of the filter via the first resistor; one end of the second capacitor is connected to the output end of the filter, and the other end is connected to the first end of the second inductor; the second end of the second inductor is connected to one end of the third capacitor; the other end of the third capacitor serves as the output end of the voltage-controlled group delay adjustment module; one end of the second resistor is connected to the output end of the voltage-controlled group delay adjustment module, and the other end is connected to the first end of the third inductor; the second end of the third inductor is grounded via the fourth capacitor; a first varactor diode, wherein the positive electrode is connected to a connection node between the second capacitor and the second inductor, and the negative electrode is connected to a connection node between the second inductor and the third capacitor, and the group delay characteristic is adjusted based on a reverse bias voltage of the first varactor diode; The transformer has a primary coil receiving a first tuning voltage and a secondary coil connected to both ends of the first varactor diode, and is used to perform voltage transformation and regulation on the first tuning voltage and apply it to both ends of the first varactor diode to change the reverse bias voltage of the first varactor diode.

2. The voltage-controlled group delay adjustment module according to claim 1, characterized in that: The filter is a low-pass filter, a high-pass filter, a band-pass filter or a direct-pass circuit.

3. The voltage-controlled group delay adjustment module according to claim 1, characterized in that: The voltage-controlled group delay adjustment module also includes a second varactor diode and a third varactor diode; the positive electrode of the second varactor diode is grounded, and the negative electrode is connected to the connection node between the first capacitor and the first inductor; the connection node between the first capacitor and the first inductor receives a second tuning voltage; the positive electrode of the third varactor diode is grounded, and the negative electrode is connected to the connection node between the fourth capacitor and the third inductor; the connection node between the fourth capacitor and the third inductor receives a third tuning voltage.

4. The voltage-controlled group delay adjustment module according to claim 1, characterized in that: The voltage-controlled group delay adjustment module further includes a fifth capacitor and a sixth capacitor; the fifth capacitor is connected between the output end of the filter and the input end of the negative group delay unit; The sixth capacitor is connected between the output end of the negative group delay unit and the output end of the voltage-controlled group delay adjustment module.

5. The voltage-controlled group delay adjustment module according to claim 1, characterized in that: The voltage-controlled group delay adjustment module further includes a temperature compensation unit, which is connected to both ends of the first varactor diode and is used to perform temperature compensation on the group delay characteristics of the voltage-controlled group delay adjustment module.

6. The voltage-controlled group delay adjustment module according to claim 5, characterized in that: The temperature compensation unit is a temperature sensitive resistor.

7. A digital control regulating circuit, characterized in that: The digital control adjustment circuit at least comprises: a DAC module and a voltage-controlled group delay adjustment module as claimed in any one of claims 1 to 6; The output end of the DAC module is connected to the voltage-controlled group delay adjustment module to provide a tuning voltage for the voltage-controlled group delay adjustment module.

8. A radio frequency microwave circuit, characterized in that: The radio frequency microwave circuit comprises at least: a voltage-controlled group delay adjustment module as described in any one of claims 1 to 6, wherein the voltage-controlled group delay adjustment module is connected in series in a signal transmission line.

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