CN203387476U

CN203387476U - Attenuator circuit structure

Info

Publication number: CN203387476U
Application number: CN201320537955.1U
Authority: CN
Inventors: 钟毅茨; 王磊; 张铁笛; 邹盼希; 张勇
Original assignee: University of Electronic Science and Technology of China
Current assignee: University of Electronic Science and Technology of China
Priority date: 2013-08-30
Filing date: 2013-08-30
Publication date: 2014-01-08
Anticipated expiration: 2023-08-30

Abstract

The utility model discloses an attenuator circuit structure. The attenuator circuit structure comprises a T-type attenuator circuit which is composed of three resistors. A field effect transistor (FET) serves as a switch of a non-parallel earthing branch circuit of the T-type attenuator circuit, and two FETs which are connected in series serve as switches of an earthing parallel branch circuit of the T-type attenuator circuit. Because the two FETs which are connected in series serve as the switches of the earthing parallel branch circuit of the T-type attenuator circuit, when an attenuator is in a reference state, the possibility that microwave signals leak to the attenuator circuit is greatly reduced; when the attenuator is in an attenuating state, serving as part of the attenuator circuit, the two FETs also improve the attenuating range of the attenuator. In order to further reduce the size of the attenuator, the form of a single-chip microwave integrated circuit is adopted in the attenuator circuit structure to keep the size of the circuit at a chip level, so that the attenuator circuit structure can be conveniently integrated with other elements.

Description

A kind of attenuator circuit structure

Technical field

The utility model belongs to communication technical field, is specifically related to a kind of design of attenuator circuit structure.

Background technology

The Digital Microwave attenuator is a kind of main element of realizing that microwave gain is controlled, has played very important effect in microwave telecommunication system.Digital pad has that working band is wide, and attenuation accuracy is high, and standing wave is better, and the Regime during recession scope is large, good stability and be easy to the advantages such as control thereby be widely adopted.The Digital Microwave attenuator is mainly used in adjusting the power output of microwave signal.For example, in microwave receiver, realize automatic gain control, improve dynamic range; In phased array radar and smart antenna, change amplitude and the phase place of antenna element excitation together with digital phase shifter, with the direction of control figure wave beam, number of beams, main secondary lobe compares etc., thereby realizes the automatically controlled scanning of wave beam.

The fade performance of Digital Microwave attenuator is mainly determined by its attenuator circuit.The applicable attenuation range of current T-shaped attenuator is less, can not adapt to than the requirement of high attenuation amount, and when attenuator during in reference state, the switch of the earth branch road of T-shaped network can not well be isolated microwave signal, greatly reduces the power output of signal.

The utility model content

In order to solve, existing T-shaped attenuator attenuation range is little, the problem such as leakage signal during reference state, and the utility model provides a kind of novel attenuator circuit structure.

For solving the problems of the technologies described above, the utility model by the following technical solutions:

A kind of attenuator circuit structure, comprise the T-shaped attenuator circuit formed by 3 resistance, the non-earth branch road of described T-shaped attenuator circuit adopts a field-effect transistor (Field Effect Transistor, FET) as switch, it is characterized in that: the ground connection parallel branch of described T-shaped attenuation network adopts two FET of series connection as switch.

Further, the grid place of described three FET all is applied with the grid voltage of controlling its conducting and pinch off.

Further, described attenuator circuit version is monolithic integrated microwave circuit.

Compared with prior art, the beneficial effects of the utility model are:

At first, attenuator circuit structure of the present utility model adopts the switch of two FET of series connection as T-shaped attenuation network earth branch road, on the one hand, when attenuator during in reference state, greatly reduce the possibility that microwave signal leaks into attenuator circuit, on the other hand, when attenuator in decay during state, two FET, as the part of attenuator circuit, have also improved the attenuation range of attenuator;

Secondly, attenuator circuit structure of the present utility model is based on Monolithic Microwave Integrated Circuit Technology, and the size of whole attenuator circuit, in chip level, has reduced the attenuator size greatly, is convenient to other components and parts integrated.

The accompanying drawing explanation

The schematic diagram that Fig. 1 is attenuator circuit structure of the present utility model;

Fig. 2 is attenuator circuit structure in embodiment input and output return loss analogous diagram when reference state and decay state when 4dB decay position;

Fig. 3 is the attenuation of attenuator circuit structure when 4dB decay position in embodiment;

Fig. 4 is the additional phase shift of attenuator circuit structure when 4dB decay position in embodiment;

Fig. 5 is loss during reference state when 4dB decay position of attenuator circuit structure in embodiment.

Embodiment

In order to make the purpose of this utility model, technical scheme and advantage clearer, below in conjunction with drawings and Examples, the utility model is further elaborated.Should be appreciated that specific embodiment described herein is only in order to explain the utility model, and be not used in restriction the utility model.

As shown in Figure 1, attenuator circuit structure in the present embodiment comprises the T-shaped attenuator circuit be comprised of 3 resistance R 1, R2 and R3, wherein A is input, B is output, R1 and R2 equal and opposite in direction, the FET2 that the non-earth branch road of T-shaped attenuator circuit adopts FET1 to connect as switch, the employing of ground connection parallel branch and FET3 are as switch,

grid

4,5,6 places of FET1, FET2 and FET3 all are applied with grid voltage, control conducting and the pinch off of FET1, FET2 and FET3 by the size of regulating grid voltage.

, add a conducting voltage and make FET1 in conducting state on the grid 4 of FET1, and add that on the

grid

5,6 of FET2 and FET3 identical pinch-off voltage makes FET2 and FET3 in the pinch off state during in reference state when the needs attenuator; When the needs attenuator in decay during state, add that on the grid 4 of FET1 a pinch-off voltage makes FET1 in off-state, add identical conducting voltage on the

grid

5,6 of FET2 and FET3, FET2 and FET3 are got final product in conducting state simultaneously, operate very easy.When attenuator during in reference state, because two FET disconnect the earth branch road of attenuator attenuator circuit, so the possibility that microwave signal leaks into attenuator circuit reduces greatly; When attenuator, when decaying state, FET2 and FET3, as the part of attenuator circuit, also can improve the attenuation range of attenuator.

In order to reduce the size of attenuator, be convenient to integrated with other components and parts, be connected, the attenuator circuit version in the present embodiment is Monolithic Microwave Integrated Circuit Technology, its size is only chip-scale.

Attenuator circuit structure in the present embodiment is carried out to emulation, and the simulation result of the return loss obtained as shown in Figure 2, can find out, during the decay state, input return loss S(1,1) be better than 18dB, output return loss S(2,2) be better than 20dB; During reference state, input return loss S(3,3) be better than 28dB, output return loss S(4,4) be better than 26dB; The attenuation simulation result obtained, as Fig. 3, can be found out, attenuation accuracy<0.04dB in frequency band, and the attenuation accuracy index is fine, proves that this structure is applicable equally for the high attenuation position; The additional phase shift simulation result obtained is as Fig. 4, and in frequency band, maximum additional phase shift is only 0.14deg; The insertion loss simulation result obtained, as Fig. 5, can find out, in frequency band, maximum insertion is only 0.7dB.

Those of ordinary skill in the art will appreciate that, embodiment described here is in order to help reader understanding's principle of the present utility model, should be understood to that protection range of the present utility model is not limited to such special statement and embodiment.Those of ordinary skill in the art can make various other various concrete distortion and combinations that do not break away from the utility model essence according to disclosed these technology enlightenments of the utility model, and these distortion and combination are still in protection range of the present utility model.

Claims

1. an attenuator circuit structure, comprise the T-shaped attenuator circuit formed by 3 resistance, the non-earth branch road of described T-shaped attenuator circuit adopts a field-effect transistor as switch, it is characterized in that: the ground connection parallel branch of described T-shaped attenuation network adopts two field-effect transistors of series connection as switch.

2. attenuator circuit structure according to claim 1, it is characterized in that: the grid place of described field-effect transistor is applied with the grid voltage of the conducting of controlling filed effect transistor and pinch off.

3. attenuator circuit structure according to claim 1 and 2, it is characterized in that: the form of this attenuator circuit structure is monolithic integrated microwave circuit.