Broadband amplitude-phase tunable analog predistorter

Abstract

The utility model discloses a broadband amplitude-phase tunable analog predistorter, which comprises a first 90-degree broadband bridge, a second 90-degree broadband bridge, a linear branch and a nonlinear branch. The first 90-degree broadband bridge is an input port device, the second 90-degree broadband bridge is an output port device, and the linear branch and the nonlinear branch are connected between the first 90-degree broadband bridge and the second 90-degree broadband bridge; the linear branch is provided with a parallel diode, an attenuator and a phase shifter so as to generate a linear signal; the nonlinear branch is provided with a Schottky barrier diode, a variable capacitance diode and a choke inductor so as to generate a nonlinear signal. The utility model relates to the technical field of microwave power amplification, an input signal is divided into two paths of signals which are equal in amplitude and have a phase difference of 90 degrees, and the two paths of signals with the phase difference of 90 degrees are finally subjected to vector synthesis on the second 90-degree broadband bridge, so that the linearity of the signals is better, and the pre-distortion effect is better.

Description

TECHNICAL FIELD

[0001] The utility model relates to in microwave power amplification technical field, specifically a wideband amplitude phase tunable analog predistorter. BACKGROUND

[0002] With the application of millimeter wave communication technology in satellite communication, satellite communication technology has been developing rapidly. Human beings are increasingly saturated in the use of spectrum resources in satellite communication. As a core device in satellite communication, millimeter wave power amplifier has a great influence on the quality and efficiency of the overall communication system. In the millimeter wave satellite communication system, the modulation signal needs to be linearly amplified in order to accurately demodulate the signal. Any amplitude or phase distortion of the modulation signal may increase the bit error rate. At the same time, with the application of new modulation technology, the linearity of the system is increasingly required, and the linearity of the system is mainly affected by the last millimeter wave high power amplifier. The amplifier has strong nonlinearity near the saturation point, and a certain power backoff is needed to ensure its linear index. However, this will greatly reduce the power capacity of the power amplifier and greatly affect the working efficiency. Therefore, it is of great significance to use linearization technology to improve the nonlinearity of the saturation region and maintain higher efficiency.

[0003] The common linearization technologies at present include: predistortion technology (including analog predistortion and digital predistortion), negative feedback technology and feedforward technology, etc. Among them, analog predistortion has simple structure, low cost, high working frequency band, high stability, high efficiency, and anti-radiation performance, and is widely used in engineering practice.

[0004] The analog predistortion technology uses the nonlinear characteristics of nonlinear devices to offset the nonlinear characteristics of the power amplifier. At present, the analog predistortion technology mainly includes four types: series transmission type, parallel transmission type, bridge reflection type and two-way type structure, etc. Most of them use Schottky barrier diodes as nonlinear signal generating devices to generate opposite characteristic curves to the target power amplifier to realize linearization output of the power amplifier.

[0005] The power amplifier currently used in satellite communication systems is mainly traveling-wave tube amplifier (TWTA) and solid-state power amplifier (SSPA). Due to the advantages of solid-state power amplifier in working bandwidth, linearity, reliability and miniaturization, it has been continuously researched and developed, and has gradually replaced the traveling-wave tube amplifier in small satellite communication.

[0006] In practical engineering, it is more suitable for satellite communication and other fields. With the rapid development of satellite communication technology, people have higher and higher requirements for the quality and information capacity of communication systems. And the competition for Ka, Ku, C and other microwave frequency bands in geostationary orbit is becoming increasingly fierce, and the space spectrum resources of lower frequency bands are becoming increasingly scarce, so it is more important to study and explore the related technology of wideband communication at higher frequency bands as soon as possible. At present, the low-orbit satellite broadband communication project at high frequency band is being vigorously developed, so it is necessary to study the related wideband linearizer as soon as possible. At present, the related linearization technology is generally limited to a relatively narrow frequency band, and the exploration in the wideband aspect is not mature, so the related research is of great significance. Practical new type content

[0007] In view of the deficiencies in the prior art, the utility model provides a kind of wideband amplitude phase tunable analog predistorter, and the input and output of predistorter standing wave, insertion loss and in-band signal flatness problem are solved by the input and output of ultra-wideband 90 ° bridge, and amplitude phase tunable property can be reached by changing the bias state of circuit, attenuator and phase quantity.

[0008] To achieve the above object, the utility model provides a kind of wideband amplitude phase tunable analog predistorter, it is characterized in that, including first 90 ° wideband bridge, second 90 ° wideband bridge, linear branch and nonlinear branch;

[0009] The first 90 ° wideband bridge is input port device, the second 90 ° wideband bridge is output port device, the linear branch, the nonlinear branch are connected between the first 90 ° wideband bridge and the second 90 ° wideband bridge;

[0010] Parallel diode, attenuator, phase shifter are generated on the linear branch linear signal;

[0011] Schottky barrier diode, varactor diode, choke inductance are generated on the nonlinear branch.

[0012] In one embodiment, the linear branch includes first tunable transmission line, first threshold capacitor, first diode, attenuator, first phase shifter, second diode, second threshold capacitor, second tunable transmission line;

[0013] The first tunable transmission line, the first threshold capacitor, the attenuator, the first phase shifter, the second threshold capacitor, the second tunable transmission line are connected in series;

[0014] The first tunable transmission line is connected with the first 90 ° wideband bridge, and the second tunable transmission line is connected with the second 90 ° wideband bridge;

[0015] An anode of the first diode is connected between the first peaking capacitor and the attenuator, and a cathode of the first diode is grounded.

[0016] An anode of the second diode is connected between the first phase shifter and the second peaking capacitor, and a cathode of the second diode is grounded.

[0017] In one of the embodiments, the nonlinear branch comprises a third tunable transmission line, a third peaking capacitor, a first Schottky barrier diode, a varactor, a radio frequency choke inductor, a fourth peaking capacitor, a second phase shifter, a second Schottky barrier diode, a fifth peaking capacitor, and a fourth tunable transmission line.

[0018] The third tunable transmission line, the third peaking capacitor, the varactor, the fourth peaking capacitor, the second phase shifter, the fifth peaking capacitor, and the fourth tunable transmission line are connected in series.

[0019] The third tunable transmission line is connected to the first 90° wideband electric bridge, and the fourth tunable transmission line is connected to the second 90° wideband electric bridge.

[0020] One end of the radio frequency choke inductor is connected between the varactor and the fourth peaking capacitor, and the other end is grounded.

[0021] An anode of the first Schottky barrier diode is connected between the third peaking capacitor and the varactor, and a cathode of the first Schottky barrier diode is grounded.

[0022] An anode of the second Schottky barrier diode is connected between the second phase shifter and the fifth peaking capacitor, and a cathode of the second Schottky barrier diode is grounded.

[0023] In one of the embodiments, an anode of the varactor is connected to the third peaking capacitor, and a cathode of the varactor is connected to the fourth peaking capacitor.

[0024] In one of the embodiments, the wideband amplitude and phase tunable analog predistorter has a frequency band width of 18GHz-50GHz.

[0025] Compared with the prior art, the utility model has the following beneficial technical effects:

[0026] 1. The utility model discloses a first 90° wideband electric bridge is arranged at the input end, and the input signal is divided into two signals with equal amplitude but 90° phase difference, which is superior to other frameworks from the mechanism of the predistortion framework, because the two signals with 90° phase difference can make the linearity of the signal better and the predistortion effect more excellent after vector synthesis in the second 90° wideband electric bridge.

[0027] 2. The utility model discloses a nonlinear branch is provided with schottky barrier diode, varactor diode combination and changes the bias voltage simultaneously, and the maximum superposition structure of the production phase expansion and amplitude expansion is maximized, and better phase and gain compensation can be reached to signal.

[0028] 3. The utility model discloses a first 90 degree broadband bridge and second 90 degree broadband bridge are set up in the input and output, have good signal flatness characteristics, can be more effective through the nonlinear branch adjustment, reach better amplitude and phase adjustable effect. DRAWINGS

[0029] In order to more clearly illustrate the technical scheme in the embodiment of the utility model or prior art, the following will briefly introduce the drawing needed to be used in the embodiment or prior art description, and obviously, the drawing in the following description is only some embodiments of the utility model, and for the ordinary skilled person in the art, other drawings can be obtained according to the structure shown in these drawings without paying creative labor.

[0030] Figure 1 It is the structure diagram of wideband amplitude and phase tunable analog pre-distortion device in the embodiment of the utility model;

[0031] Figure 2 It is the simulation result schematic diagram of phase compensation curve of wideband amplitude and phase tunable analog pre-distortion device in the embodiment of the utility model;

[0032] Figure 3 It is the simulation result schematic diagram of gain compensation curve of wideband amplitude and phase tunable analog pre-distortion device in the embodiment of the utility model.

[0033] Drawing reference: first 90 degree broadband bridge 1, first tunable transmission line 2, first spacer capacitor 3, first diode 4, attenuator 5, first phase shifter 6, second diode 7, second spacer capacitor 8, second tunable transmission line 9, second 90 degree broadband bridge 10, third tunable transmission line 11, third spacer capacitor 12, first schottky barrier diode 13, varactor diode 14, radio frequency choke inductance 15, fourth spacer capacitor 16, second phase shifter 17, second schottky barrier diode 18, fifth spacer capacitor 19, fourth tunable transmission line 20.

[0034] The utility model discloses the realization, functional characteristics and advantages will be further explained with reference to the embodiment. Specific implementation

[0035] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of the present application.

[0036] It should be noted that all the directional indications (such as up, down, left, right, front, back, and the like) in the embodiments of the present application are only used to explain the relative positional relationship, movement condition and the like between components in a certain specific posture (as shown in the drawings), and if the specific posture changes, the directional indications also change accordingly.

[0037] In addition, the description of "first", "second" and the like in the present application is only for the purpose of description, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "multiple" is at least two, for example, two, three, and the like, unless otherwise specifically limited.

[0038] In the present application, unless otherwise specifically defined and limited, the terms "connection", "fixing" and the like should be understood in a broad sense, for example, "fixing" can be fixed connection, can also be detachable connection, or integral; can be mechanical connection, can also be electrical connection, can also be physical connection or wireless communication connection; can be directly connected, can also be indirectly connected through an intermediate medium, can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise specifically limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0039] In addition, the technical solutions of each embodiment of the present application can be combined with each other, but it must be based on the fact that a person skilled in the art can realize it, when the combination of technical solutions appears contradictory or unachievable, it should be considered that the combination of technical solutions does not exist, and is not within the scope of protection required by the present application.

[0040] For example, Figure 1The wideband amplitude and phase tunable analog predistorter disclosed by the embodiment mainly comprises a first 90° wideband bridge 1, a second 90° wideband bridge 10, a linear branch and a nonlinear branch. The first 90° wideband bridge 1 is an input port device, the second 90° wideband bridge 10 is an output port device, and the linear branch and the nonlinear branch are connected between the first 90° wideband bridge 1 and the second 90° wideband bridge 10. The linear branch has a parallel diode, an attenuator and a phase shifter to generate a linear signal. The nonlinear branch has a Schottky barrier diode, a varactor diode and a choke inductor to generate a nonlinear signal.

[0041] In a specific application, the radio frequency signal is divided into two paths with the same amplitude but a phase difference of 90° after passing through the first 90° wideband bridge 1. One path generates a linear signal through the linear branch with a parallel diode, an attenuator and a phase shifter, and the other path generates a nonlinear signal through the nonlinear branch with a Schottky barrier diode, a varactor diode and a choke inductor. The signals of the two branches are vector synthesized at the second 90° wideband bridge 10 and then output. By adjusting the bias voltage of the nonlinear branch, the phase shifter, the attenuator of the linear branch and the phase shifter, the amplitude and phase can be adjusted in a wide frequency band.

[0042] The linear branch comprises a first tunable transmission line 2, a first threshold capacitor 3, a first diode 4, an attenuator 5, a first phase shifter 6, a second diode 7, a second threshold capacitor 8 and a second tunable transmission line 9. The first tunable transmission line 2, the first threshold capacitor 3, the attenuator 5, the first phase shifter 6, the second threshold capacitor 8 and the second tunable transmission line 9 are connected in series, the first tunable transmission line 2 is connected with the first 90° wideband bridge 1, and the second tunable transmission line 9 is connected with the second 90° wideband bridge 10. The anode of the first diode 4 is connected between the first threshold capacitor 3 and the attenuator 5, and the cathode of the first diode 4 is grounded. The anode of the second diode 7 is connected between the first phase shifter 6 and the second threshold capacitor 8, and the cathode of the second diode 7 is grounded.

[0043] The nonlinear branch comprises a third tunable transmission line 11, a third shunt capacitance 12, a first Schottky barrier diode 13, a varactor diode 14, a radio frequency choke inductance 15, a fourth shunt capacitance 16, a second phase shifter 17, a second Schottky barrier diode 18, a fifth shunt capacitance 19, and a fourth tunable transmission line 20. The third tunable transmission line 11, the third shunt capacitance 12, the varactor diode 14, the fourth shunt capacitance 16, the second phase shifter 17, the fifth shunt capacitance 19, and the fourth tunable transmission line 20 are connected in series, the third tunable transmission line 11 is connected to the first 90° broadband bridge 1, and the fourth tunable transmission line 20 is connected to the second 90° broadband bridge 10. One end of the radio frequency choke inductance 15 is connected between the varactor diode 14 and the fourth shunt capacitance 16, and the other end is grounded. The anode of the first Schottky barrier diode 13 is connected between the third shunt capacitance 12 and the varactor diode 14, and the cathode of the first Schottky barrier diode 13 is grounded. The anode of the second Schottky barrier diode 18 is connected between the second phase shifter 17 and the fifth shunt capacitance 19, and the cathode of the second Schottky barrier diode 18 is grounded. The anode of the varactor diode 14 is connected to the third shunt capacitance 12, and the cathode of the varactor diode 14 is connected to the fourth shunt capacitance 16. In the nonlinear branch, the bias conditions of the first Schottky barrier diode 13 and the second Schottky barrier diode 18 are changed to achieve gain adjustment and phase expansion, and the bias condition of the varactor diode is changed to achieve gain expansion and phase expansion.

[0044] The frequency band width of the wide-band amplitude and phase tunable analog pre-distortion device in the embodiment is 18GHz-50GHz, the first 90° broadband bridge 1 and the second 90° broadband bridge 10 have good signal flatness characteristics, and the nonlinear branch can be adjusted more effectively to achieve better amplitude and phase adjustment.

[0045] Reference Figure 2 With Figure 3 The simulation result schematic diagram of the phase compensation curve and the simulation result schematic diagram of the gain compensation curve of the wide-band amplitude and phase tunable analog pre-distortion device in the embodiment are shown in Figs. 4 and 5, respectively. Figure 2 Figure 3 It can be known that the wide-band amplitude and phase tunable analog pre-distortion device in the embodiment can effectively achieve phase and gain expansion when the frequency band width is 18GHz-50GHz.

[0046] The above description is only preferred embodiments of the utility model, and does not limit the patent range of the utility model, and any equivalent structural transformation made by using the utility model specification and the attached drawings or directly / indirectly applied in other related technical fields under the utility model concept of the utility model is included in the patent protection range of the utility model.​

Claims

1. A wideband amplitude and phase tunable analog predistorter, characterized in that: It includes a first 90° broadband bridge, a second 90° broadband bridge, a linear branch and a nonlinear branch; The first 90° broadband bridge is an input port device, the second 90° broadband bridge is an output port device, and the linear branch and the nonlinear branch are both connected between the first 90° broadband bridge and the second 90° broadband bridge; The linear branch has a parallel diode, an attenuator, and a phase shifter to generate a linear signal; The nonlinear branch is provided with a Schottky barrier diode, a variable capacitance diode, and a choke inductor to generate a nonlinear signal.

2. The wideband amplitude and phase tunable analog predistorter according to claim 1, characterized in that: The linear branch includes a first tunable transmission line, a first isolation capacitor, a first diode, an attenuator, a first phase shifter, a second diode, a second isolation capacitor, and a second tunable transmission line; The first tunable transmission line, the first isolation capacitor, the attenuator, the first phase shifter, the second isolation capacitor, and the second tunable transmission line are sequentially connected in series; The first tunable transmission line is connected to the first 90° broadband bridge, and the second tunable transmission line is connected to the second 90° broadband bridge; The anode of the first diode is connected between the first isolation capacitor and the attenuator, and the cathode of the first diode is grounded; An anode of the second diode is connected between the first phase shifter and the second isolation capacitor, and a cathode of the second diode is grounded.

3. The wideband amplitude and phase tunable analog predistorter according to claim 1, characterized in that: The nonlinear branch includes a third tunable transmission line, a third isolation capacitor, a first Schottky barrier diode, a varactor diode, a radio frequency choke inductor, a fourth isolation capacitor, a second phase shifter, a second Schottky barrier diode, a fifth isolation capacitor, and a fourth tunable transmission line; The third tunable transmission line, the third isolation capacitor, the varactor diode, the fourth isolation capacitor, the second phase shifter, the fifth isolation capacitor, and the fourth tunable transmission line are sequentially connected in series; The third tunable transmission line is connected to the first 90° broadband bridge, and the fourth tunable transmission line is connected to the second 90° broadband bridge; One end of the radio frequency choke inductor is connected between the varactor diode and the fourth isolation capacitor, and the other end is grounded; The anode of the first Schottky barrier diode is connected between the third isolation capacitor and the varactor diode, and the cathode of the first Schottky barrier diode is grounded; An anode of the second Schottky barrier diode is connected between the second phase shifter and the fifth isolation capacitor, and a cathode of the second Schottky barrier diode is grounded.

4. The wideband amplitude and phase tunable analog predistorter according to claim 3, characterized in that: The anode of the varactor diode is connected to the third isolation capacitor, and the cathode of the varactor diode is connected to the fourth isolation capacitor.

5. The wideband amplitude and phase tunable analog predistorter according to any one of claims 1 to 4, characterized in that: The frequency bandwidth of the wide-band amplitude and phase tunable analog predistorter is 18 GHz to 50 GHz.

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