CN213693651U

CN213693651U - Broadband attenuator

Info

Publication number: CN213693651U
Application number: CN202023083717.7U
Authority: CN
Inventors: 薛红喜
Original assignee: Kunshan Wangfan Information Technology Co ltd
Current assignee: Kunshan Wangfan Information Technology Co ltd
Priority date: 2020-12-21
Filing date: 2020-12-21
Publication date: 2021-07-13
Anticipated expiration: 2030-12-21

Abstract

The utility model relates to the technical field of electronic communication, in particular to a broadband attenuator, which comprises a digital broadband attenuator and an analog digital attenuator, wherein the digital broadband attenuator comprises a switch resistor, a plurality of resistors are connected in parallel between a signal input end and an output end of an electronic communication system, each resistor is connected with a switch in series to form a switch resistor array attenuator, the analog digital attenuator comprises an operational amplifier, a first resistor, a second resistor, a third resistor and a variable voltage-controlled resistor, one end of the first resistor is connected with the output end of the digital broadband attenuator, the other end of the first resistor is connected with the positive input end of the operational amplifier, the negative input end of the operational amplifier is grounded after being connected with the second resistor in series, a third resistor is connected in series between the positive input end and the output end of the operational amplifier, the third resistor is connected with the variable voltage-controlled resistor in parallel, and the control end of the variable voltage, the utility model has the characteristics of continuously adjustable, broadband, constant time delay, fixed gain/insertion loss.

Description

Broadband attenuator

Technical Field

The utility model relates to an electronic communication technical field, specific field is a broadband attenuator.

Background

Broadband attenuators are important components in communication systems. The requirements for broadband attenuators in modern broadband communication systems are: 1. broad band (> 10%); 2. an in-band uniform amplitude-frequency response; 3. high precision (flatness/error in band: ≦ 0.5 dB); 4. constant group delay; 5. fixed insertion loss/gain; 6. continuously adjustable [ 0, -32 ], [ 0, -64 ], or [ 0, -128 ].

However, the research in the industry is mainly in two directions: broadband and amplitude-frequency uniformity. Among them, most of the industry concerns are controllability of attenuation or flatness within the band. Whether discrete integration, capacitive compensation or discrete analog control, depends on the absolute precision of the process to realize the precision of the attenuator. In these cases, the group delay characteristics of the attenuators are not of interest. Achieving adjustable amplitude-frequency uniformity is particularly challenging, while maintaining in-band amplitude-frequency flatness is another challenge. The group delay and attenuation characteristics of different amplitude responses are the indexes ignored by most people.

Most of the proposals for broadband characteristics adopt broadband devices to complete, but the flatness and precision of the broadband are determined by the adopted basic devices, materials and the like. The bandwidth and the flatness in the band are not controllable and adjustable.

The attenuator of this section's research mainly focuses on two aspects: broadband characteristics and amplitude equalization. Among other things, implementing a broadband attenuator is particularly difficult. For broadband attenuators, voltage-controlled attenuators implemented with PIN-tubes are the most well known. The attenuation value of the attenuator (A type) is continuously adjustable; the defects are that the broadband characteristic is not controllable and the amplitude uniformity is not good; it is particularly important that its amplitude-frequency and group delay characteristics are accompanied by uncontrollable variations as the phase and frequency change.

With the progress of integrated circuit technology and technology, fixed or adjustable attenuators are made with switches and fixed resistors. The characteristics of such (class B) attenuators: the bandwidth is wider than class a, but not continuously adjustable. The biggest disadvantage is that the attenuation is determined by the absolute value of the resistor, resulting in large attenuation error.

In summary, the attenuator with adjustable broadband, wide-range, continuous attenuation and stable amplitude-frequency characteristic and constant group delay characteristic required in modern communication systems does not exist at present.

Therefore, the need for a broadband attenuator with the above features is very urgent.

SUMMERY OF THE UTILITY MODEL

To the deficiency that prior art exists, the utility model aims to provide a broadband attenuator.

In order to achieve the above object, the utility model provides a following technical scheme: a broadband attenuator comprises a digital broadband attenuator and an analog digital attenuator, the digital broadband attenuator comprises a switch resistor, a plurality of resistors are connected in parallel between the signal input end and the output end of the electronic communication system, and each resistor is connected with a switch in series to form a switch resistor array attenuator, the analog digital attenuator comprises an operational amplifier, a first resistor, a second resistor, a third resistor and a variable voltage-controlled resistor, wherein one end of the first resistor is connected with the output end of the digital broadband attenuator, the other end of the first resistor is connected with the positive input end of the operational amplifier, the negative input end of the operational amplifier is connected with the second resistor in series and then grounded, the third resistor is connected between the positive input end and the output end of the operational amplifier in series, the third resistor is connected with the variable voltage-controlled resistor in parallel, the control end of the variable voltage-controlled resistor is connected with an external control signal, and the output end of the operational amplifier outputs a signal.

Preferably, the variable voltage-controlled resistor and the third resistor are respectively connected in series with an independent switch.

Preferably, the switches in the switch resistor are all field effect transistors, and the external control signal is input and connected with the control end of the field effect transistor.

Preferably, the two independent switches are both field effect transistors, and the external control signal is input and connected with the control ends of the field effect transistors.

Compared with the prior art, the beneficial effects of the utility model are that: the attenuator with the broadband, the stable amplitude-frequency characteristic and the fixed group delay characteristic is designed, so that the attenuator has the characteristics of fixed continuously adjustable controllable attenuation and good amplitude balance degree in an extremely wide working frequency band, and has the characteristics of continuous adjustability, broadband, constant delay, fixed gain/insertion loss.

Drawings

FIG. 1 is a schematic diagram of the structure of the present invention;

FIG. 2 is a schematic diagram of the digital broadband attenuator of the present invention;

FIG. 3 is a schematic diagram of the structure of the analog-digital attenuator of the present invention;

FIG. 4 is a table of individual switch states in the analog digital attenuator;

FIG. 5 is a table showing the variation of the attenuation value of the analog digital attenuator.

In the figure: 1. a digital broadband attenuator; 2. an analog-to-digital attenuator; 3. a switch resistor; 4. an operational amplifier; 5. a first resistor; 6. a second resistor; 7. a third resistor; 8. a variable voltage controlled resistor.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

Referring to fig. 1 to 3, the present invention provides a technical solution: the utility model provides a broadband attenuator, includes digital broadband attenuator and analog digital attenuator, digital broadband attenuator includes the switch resistance, and it has a plurality of resistance to connect in parallel between electronic communication system's signal input end and output, and all establish ties on every resistance has the switch, constitutes switch resistance array attenuator, the switch circuit structure of constitution, and is discrete controllable.

The analog digital attenuator comprises an operational amplifier, a first resistor, a second resistor, a third resistor and a variable voltage-controlled resistor, wherein one end of the first resistor is connected with the output end of the digital broadband attenuator, the other end of the first resistor is connected with the positive input end of the operational amplifier, the negative input end of the operational amplifier is connected with the second resistor in series and then is grounded, the third resistor is connected between the positive input end and the output end of the operational amplifier in series, the third resistor is connected with the variable voltage-controlled resistor in parallel, the control end of the variable voltage-controlled resistor is connected with an external control signal, the output end of the operational amplifier outputs a signal, and the attenuation value is determined by the corresponding relative value; different attenuation values can be realized by controlling the ratio of the variable voltage-controlled resistor Rv to the resistor Rr instead of the absolute value of the resistor; similarly, the 0dB attenuation or other values of the reference path are determined by the ratio of the resistance three/the resistance one Rr; the resistance value of the variable voltage-controlled resistor Rv is continuously adjustable, and the attenuation value of the variable voltage-controlled resistor Rv can be continuously changed through the conversion of an external voltage signal. Such as the independent switch state table of fig. 4, and the attenuation value continuous adjustment change table of fig. 5.

And the variable voltage-controlled resistor and the resistor III are respectively connected in series with an independent switch.

The switches in the switch resistor are all field effect transistors, and external control signals are input and connected with the control ends of the field effect transistors.

The two independent switches are both field effect transistors, and external control signals are input and connected with control ends of the field effect transistors.

By the technical scheme, the attenuation is continuously adjustable, the regulation and control range is large, the flatness in the band is controllable, the group delay is constant, and the analog number is controllable.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims

1. A broadband attenuator, characterized by: the signal passes through the digital broadband attenuator module and the analog digital attenuator module and then outputs a stable broadband attenuation signal.

2. A broadband attenuator according to claim 1, wherein: the digital broadband attenuator module comprises a switch resistor, a plurality of resistors are connected in parallel between a signal input end and an output end of the electronic communication system, and a switch is connected in series on each resistor to form a switch resistor array attenuator.

3. A broadband attenuator according to claim 2, wherein: the analog digital attenuator module comprises an operational amplifier, a first resistor, a second resistor, a third resistor and a variable voltage-controlled resistor, wherein one end of the first resistor is connected with the output end of the digital broadband attenuator, the other end of the first resistor is connected with the positive input end of the operational amplifier, the negative input end of the operational amplifier is grounded after being connected with the second resistor in series, the third resistor is connected between the positive input end and the output end of the operational amplifier in series, the third resistor is connected with the variable voltage-controlled resistor in parallel, the control end of the variable voltage-controlled resistor is connected with an external control signal, and the output end of the operational amplifier outputs the signal.

4. A broadband attenuator according to claim 3, wherein: and the variable voltage-controlled resistor and the resistor III are respectively connected in series with an independent switch.

5. The broadband attenuator of claim 4, wherein: the switches in the switch resistor are all field effect transistors, and external control signals are input and connected with the control ends of the field effect transistors.

6. The broadband attenuator of claim 5, wherein: the two independent switches are both field effect transistors, and external control signals are input and connected with control ends of the field effect transistors.