阅读说明：本技术 超宽带高精度差分衰减器 (Ultra-wideband high-precision differential attenuator ) 是由 尤肖虎 赵涤燹 顾鹏 张成军 于 2020-05-19 设计创作，主要内容包括：本发明公开了一种超宽带高精度差分衰减器,包括依次连接的第一差分8dB衰减单元、差分0.5dB衰减单元、差分4dB衰减单元、第二差分8dB衰减单元、差分2dB衰减单元、差分1dB衰减单元和第三差分8dB衰减单元,所述的各差分衰减单元均由上下两个单端半电路以中心轴H对称构成。通过上述结构,本发明可以提升衰减器的高频工作能力、调幅精度、匹配性能以及双向工作的一致性,还可以提升衰减器的线性度,增强衰减器应用于高功率场景的能力,并且抑制共模干扰信号的影响,增强可靠性。(The invention discloses an ultra-wideband high-precision differential attenuator which comprises a first differential 8dB attenuation unit, a differential 0.5dB attenuation unit, a differential 4dB attenuation unit, a second differential 8dB attenuation unit, a differential 2dB attenuation unit, a differential 1dB attenuation unit and a third differential 8dB attenuation unit which are sequentially connected, wherein each differential attenuation unit is formed by an upper single-end half circuit and a lower single-end half circuit which are symmetrical by using a central shaft H. Through the structure, the high-frequency working capacity, the amplitude modulation precision, the matching performance and the consistency of bidirectional working of the attenuator can be improved, the linearity of the attenuator can be improved, the capacity of the attenuator applied to a high-power scene is enhanced, the influence of a common-mode interference signal is inhibited, and the reliability is enhanced.)

1. The ultra-wideband high-precision differential attenuator is characterized by comprising a first differential 8dB attenuation unit, a differential 0.5dB attenuation unit, a differential 4dB attenuation unit, a second differential 8dB attenuation unit, a differential 2dB attenuation unit, a differential 1dB attenuation unit and a third differential 8dB attenuation unit which are sequentially connected, wherein each differential attenuation unit is formed by an upper single-end half circuit and a lower single-end half circuit in a symmetrical mode through a central shaft H.

2. The ultra-wideband high precision differential attenuator of claim 1, wherein: the differential 0.5dB attenuation unit and the differential 1dB attenuation unit are of differential simplified T-shaped structures, the differential 2dB attenuation unit and the differential 4dB attenuation unit are of differential capacitance compensation T-shaped structures, and the first differential 8dB attenuation unit, the second differential 8dB attenuation unit and the third differential 8dB attenuation unit are of differential capacitance compensation II-shaped structures.

3. The ultra-wideband high precision differential attenuator of claim 1, wherein: the first, second, third, and fourth differential 8dB attenuation units include upper side attenuation units (100, 200, 300, 400, 500, 600, 700) and lower side attenuation units (110, 210, 310, 410, 510, 610, 710).

4. The ultra-wideband high precision differential attenuator of claim 1, wherein: the device sizes of the first differential 8dB attenuation unit (100, 110), the second differential 8dB attenuation unit (400, 410) and the third differential 8dB attenuation unit (700, 710) are the same, and the first differential 8dB attenuation unit (100, 110) and the third differential 8dB attenuation unit (700, 710) use the same control signal.

5. The ultra-wideband high precision differential attenuator of claim 2, wherein: the differential simplified T-shaped structure is composed of two identical single-ended simplified T-shaped structures, and a single-ended half circuit (200, 600) of the differential simplified T-shaped structure is composed of a first transistor (201, 601) and a first resistor (202, 602), wherein: the grid of the first transistor (201, 601) is connected with the digital control voltage, the drain is connected with one end of the first resistor (202, 602), and the source is connected with the other single-ended half circuit (210, 610); the other end of the first resistor (202, 602) is connected to the signal path.

6. The ultra-wideband high precision differential attenuator of claim 2, wherein: the differential capacitance compensation type T-shaped structure is composed of two same single-ended capacitance compensation type T-shaped structures, and a single-ended half circuit (300, 500) of the differential capacitance compensation type T-shaped structure is composed of a second transistor (301, 501), a second resistor (303, 503), a first capacitor (302, 502), a third resistor (304, 504), a fourth resistor (305, 505) and a third transistor (306, 506), wherein: the second resistors (303, 503) are connected with the first capacitors (302, 502) in parallel, the gates of the second transistors (301, 501) are connected with the digital control voltage, the drains are connected with the common ends of the second resistors (303, 503) and the first capacitors (302, 502), and the sources are connected with the other single-ended half circuit (310, 510); the other common ends of the second resistors (303, 503) and the first capacitors (302, 502) are respectively connected with one ends of the third resistors (304, 504) and one ends of the fourth resistors (305, 505), and the other ends of the third resistors (304, 504) and the other ends of the fourth resistors (305, 505) are respectively connected to the signal paths; the gates of the third transistors (306, 506) are coupled to a digital control voltage, and the drains and sources are coupled to the signal path, respectively.

7. The ultra-wideband high precision differential attenuator of claim 2, wherein: the differential capacitance compensation type pi-type structure is composed of two identical single-ended capacitance compensation type pi-type structures, and a single-ended half circuit (100, 400, 700) of the differential capacitance compensation type pi-type structure is composed of a fourth transistor (101, 401, 701), a fifth transistor (102, 402, 702), a fifth resistor (103, 403, 703), a sixth resistor (104, 404, 704), a second capacitor (105, 405, 705), a third capacitor (106, 406, 706), a seventh resistor (107, 407, 707) and a sixth transistor (108, 408, 708), wherein: the fifth resistor (103, 403, 703) is connected with the second capacitor (105, 405, 705) in parallel, and the sixth resistor (104, 404, 704) is connected with the third capacitor (106, 406, 706) in parallel; the grid electrode of the fourth transistor (101, 401, 701) is connected with the digital control voltage, the drain electrode of the fourth transistor is connected with the common end of the fifth resistor (103, 403, 703) and the second capacitor (105, 405, 705), and the source electrode of the fourth transistor is connected with the other single-ended half circuit (110, 410, 710); the grid electrode of the fifth transistor (102, 402, 702) is connected with the digital control voltage, the drain electrode is connected with the sixth resistor (104, 404, 704) and one common end of the third capacitor (106, 406, 706), and the source electrode is connected with the other single-ended half circuit (110, 410, 710); the other common end of the fifth resistor (103, 403, 703) and the second capacitor (105, 405, 705), the other common end of the sixth resistor (104, 404, 704) and the third capacitor (106, 406, 706) are respectively connected to the signal path, and a seventh resistor (107, 407, 707) is further connected in series between the other common end of the fifth resistor (103, 403, 703) and the second capacitor (105, 405, 705), and the other common end of the sixth resistor (104, 404, 704) and the third capacitor (106, 406, 706); the sixth transistor (108, 408, 708) has a gate connected to the digital control voltage, and a drain and a source respectively connected to the signal path.

8. The ultra-wideband high precision differential attenuator of claim 1, wherein: first to sixteenth inductors (800, 801, 802, 803, 804, 805, 806, 807, 900, 901, 902, 903, 904, 905, 906, 907) are inserted between adjacent two of the first differential 8dB attenuation unit (100, 110), the differential 0.5dB attenuation unit (200, 210), the differential 4dB attenuation unit (300, 310), the second differential 8dB attenuation unit (400, 410), the differential 2dB attenuation unit (500, 510), the differential 1dB attenuation unit (600, 610), and the third differential 8dB attenuation unit (700, 710) for impedance matching.

Technical Field

The invention relates to the technical field of electronic circuit design, in particular to an ultra-wideband high-precision differential attenuator.

Background

In recent years, new-generation communication technologies have been developed rapidly, and communication based on the sub-6GHz band has not been able to meet the increasing bandwidth requirement, so communication based on high frequency above 6GHz, such as millimeter wave 5G communication, broadband satellite communication, etc., has become a development direction of great interest. Although high frequency communication can provide a large bandwidth, the problems of high loss and low coverage rate of the high frequency communication still need to be solved. The phased array technology can effectively compensate high loss of high-frequency communication and improve the coverage capability of the high-frequency communication, so that the phased array technology is widely used in a high-frequency communication system. Through the multi-antenna array and the beam forming technology, the phased array system can realize higher output power to overcome the propagation loss; meanwhile, the direction of the wave beam can be adjusted according to the real-time requirement of the user, and flexible signal coverage is provided.

Each array element of the phased array system needs an amplitude control module, which is used for compensating amplitude deviation among channels on one hand and is used for beam forming on the other hand so as to reduce the side lobe of a synthesized beam. The typical amplitude control module comprises a variable gain amplifier and an attenuator, wherein the variable gain amplifier can provide certain gain while modulating amplitude, but consumes direct current power; in contrast, the attenuator has no direct current power consumption and is a preferred scheme for realizing low-power-consumption amplitude modulation.

The switch type attenuator mainly comprises a transistor switch and a resistor, and has the advantages of small size and simple control. By cascading multiple attenuation units, the switch-type attenuator can realize amplitude adjustment in a large range. However, the performance of the switched attenuator is limited by the performance of the transistor in the process. At low frequencies, the attenuator generally achieves better performance because the effect of transistor parasitic parameters is not significant. But to high frequencies (e.g., the millimeter wave band), the parasitic parameters of the transistor will degrade the performance of the attenuator, thus limiting its application to high frequencies. Meanwhile, as the attenuation value of the attenuation unit increases, the influence of the parasitic parameter of the transistor becomes large, and thus it becomes a design challenge to implement a wide range of attenuation in a high frequency band. In addition, the existing design usually adopts a single-ended attenuator, and although the linearity of the attenuator is better than that of an active variable gain amplifier, the linearity still needs to be further improved in a high-power application scene; also, in a circuit system where each module is of a differential structure, an attenuator of a single-ended structure would not be suitable for being cascaded into a link.

Disclosure of Invention

The invention aims to provide an ultra-wideband high-precision differential attenuator, which can improve the linearity of the attenuator, enhance the capability of the attenuator applied to a high-power scene, inhibit the influence caused by a common-mode interference signal, enhance the reliability of the attenuator, integrally improve the working capability of the attenuator at high frequency, and improve the matching performance, the amplitude modulation precision and the consistency of two-way working of the attenuator.

In order to solve the technical problems, the invention adopts a technical scheme that: the ultra-wideband high-precision differential attenuator comprises a first differential 8dB attenuation unit, a differential 0.5dB attenuation unit, a differential 4dB attenuation unit, a second differential 8dB attenuation unit, a differential 2dB attenuation unit, a differential 1dB attenuation unit and a third differential 8dB attenuation unit which are sequentially connected, wherein each differential attenuation unit is formed by an upper single-end half circuit and a lower single-end half circuit which are symmetrical by using a central shaft H.

Furthermore, the differential 0.5dB attenuation unit and the differential 1dB attenuation unit adopt differential simplified T-shaped structures, the differential 2dB attenuation unit and the differential 4dB attenuation unit adopt differential capacitance compensation T-shaped structures, and the first differential 8dB attenuation unit, the second differential 8dB attenuation unit and the third differential 8dB attenuation unit adopt differential capacitance compensation n-shaped structures.

Further, the first, second, third, and fourth differential 8dB attenuation units, the differential 0.5dB attenuation units, the differential 4dB attenuation units, the second, and third differential 8dB attenuation units, the differential 2dB attenuation units, the differential 1dB attenuation units, and the third differential 8dB attenuation units include upper side attenuation units (100, 200, 300, 400, 500, 600, 700) and lower side attenuation units (110, 210, 310, 410, 510, 610, 710).

Further, the device size of the first differential 8dB attenuation unit (100, 110), the second differential 8dB attenuation unit (400, 410) and the third differential 8dB attenuation unit (700, 710) are the same, and the first differential 8dB attenuation unit (100, 110) and the third differential 8dB attenuation unit (700, 710) use the same control signal.

Further, the differential simplified T-type structure is composed of two identical single-ended simplified T-type structures, and a single-ended half circuit (200, 600) thereof is composed of a first transistor (201, 601) and a first resistor (202, 602), wherein: the grid of the first transistor (201, 601) is connected with the digital control voltage, the drain is connected with one end of the first resistor (202, 602), and the source is connected with the other single-ended half circuit (210, 610); the other end of the first resistor (202, 602) is connected to the signal path.

Further, the differential capacitance compensation type T-shaped structure is composed of two identical single-ended capacitance compensation type T-shaped structures, and the single-ended half circuit (300, 500) is composed of a second transistor (301, 501), a second resistor (303, 503), a first capacitor (302, 502), a third resistor (304, 504), a fourth resistor (305, 505) and a third transistor (306, 506), wherein: the second resistors (303, 503) are connected with the first capacitors (302, 502) in parallel, the gates of the second transistors (301, 501) are connected with the digital control voltage, the drains are connected with the common ends of the second resistors (303, 503) and the first capacitors (302, 502), and the sources are connected with the other single-ended half circuit (310, 510); the other common ends of the second resistors (303, 503) and the first capacitors (302, 502) are respectively connected with one ends of the third resistors (304, 504) and one ends of the fourth resistors (305, 505), and the other ends of the third resistors (304, 504) and the other ends of the fourth resistors (305, 505) are respectively connected to the signal paths; the gates of the third transistors (306, 506) are coupled to a digital control voltage, and the drains and sources are coupled to the signal path, respectively.

Further, the differential capacitance compensation Π -type structure is formed by two identical single-ended capacitance compensation Π -type structures, and a single-ended half circuit (100, 400, 700) of the differential capacitance compensation Π -type structure is formed by a fourth transistor (101, 401, 701), a fifth transistor (102, 402, 702), a fifth resistor (103, 403, 703), a sixth resistor (104, 404, 704), a second capacitor (105, 405, 705), a third capacitor (106, 406, 706), a seventh resistor (107, 407, 707), and a sixth transistor (108, 408, 708), wherein: the fifth resistor (103, 403, 703) is connected with the second capacitor (105, 405, 705) in parallel, and the sixth resistor (104, 404, 704) is connected with the third capacitor (106, 406, 706) in parallel; the grid electrode of the fourth transistor (101, 401, 701) is connected with the digital control voltage, the drain electrode of the fourth transistor is connected with the common end of the fifth resistor (103, 403, 703) and the second capacitor (105, 405, 705), and the source electrode of the fourth transistor is connected with the other single-ended half circuit (110, 410, 710); the grid electrode of the fifth transistor (102, 402, 702) is connected with the digital control voltage, the drain electrode is connected with the sixth resistor (104, 404, 704) and one common end of the third capacitor (106, 406, 706), and the source electrode is connected with the other single-ended half circuit (110, 410, 710); the other common end of the fifth resistor (103, 403, 703) and the second capacitor (105, 405, 705), the other common end of the sixth resistor (104, 404, 704) and the third capacitor (106, 406, 706) are respectively connected to the signal path, and a seventh resistor (107, 407, 707) is further connected in series between the other common end of the fifth resistor (103, 403, 703) and the second capacitor (105, 405, 705), and the other common end of the sixth resistor (104, 404, 704) and the third capacitor (106, 406, 706); the sixth transistor (108, 408, 708) has a gate connected to the digital control voltage, and a drain and a source respectively connected to the signal path.

Further, first to sixteenth inductors (800, 801, 802, 803, 804, 805, 806, 807, 900, 901, 902, 903, 904, 905, 906, 907) are inserted between adjacent two of the first differential 8dB attenuation unit (100, 110), the differential 0.5dB attenuation unit (200, 210), the differential 4dB attenuation unit (300, 310), the second differential 8dB attenuation unit (400, 410), the differential 2dB attenuation unit (500, 510), the differential 1dB attenuation unit (600, 610), and the third differential 8dB attenuation unit (700, 710) for impedance matching.

The invention has the beneficial effects that: the ultra-wideband high-precision differential attenuator has the following advantages:

firstly, the invention provides a differential attenuator structure, on one hand, the linearity of the attenuator is improved, the capability of the attenuator applied to a high-power scene is enhanced, on the other hand, the influence brought by a common-mode interference signal is inhibited, and the reliability of the attenuator is enhanced;

secondly, the 16dB attenuation effect is realized by jointly controlling the two 8dB units, so that the 16dB attenuation unit is prevented from being directly used, and the working capacity of the attenuator at high frequency is integrally improved;

thirdly, based on simplified T-type, capacitance-compensated pi-type attenuation structures, the present invention provides a selection and arrangement method for attenuation structures suitable for large amplitude modulation ranges (e.g., above 20 dB), which can improve matching performance, amplitude modulation accuracy, and consistency of bidirectional operation of the attenuator.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments described in the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

Fig. 1 is a schematic circuit diagram of an ultra-wideband high-precision differential attenuator according to the present invention;

FIG. 2 is a result of a 6-bit amplitude adjustment of an ultra-wideband high-precision differential attenuator of the present invention;

FIG. 3 is the result of the amplitude modulation root mean square error of an ultra-wideband high precision differential attenuator of the present invention;

fig. 4 is the result of the amplitude modulated additional phase of an ultra-wideband high precision differential attenuator of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, embodiments of the present invention are described in detail below with reference to the accompanying drawings. Examples of these preferred embodiments are illustrated in the accompanying drawings. The embodiments of the invention shown in the drawings and described in accordance with the drawings are exemplary only, and the invention is not limited to these embodiments.

It should be noted that, in order to avoid obscuring the present invention with unnecessary details, only the structures and/or processing steps closely related to the scheme according to the present invention are shown in the drawings, and other details not so relevant to the present invention are omitted.

Also, in the description of the present invention, the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. indicate orientations or positional relationships based on those shown in the drawings, only for convenience of description and simplification of description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

The invention discloses an ultra-wideband high-precision differential attenuator, which relates to the application fields of: satellite communications, millimeter wave 5G communications, phased array systems, and the like.