CN108091973B

CN108091973B - Miniaturized broadband power distribution network

Info

Publication number: CN108091973B
Application number: CN201711193717.2A
Authority: CN
Inventors: 范姣婧; 郑欢; 李明亮
Original assignee: Shanghai Radio Equipment Research Institute
Current assignee: Shanghai Radio Equipment Research Institute
Priority date: 2017-11-24
Filing date: 2017-11-24
Publication date: 2020-07-31
Anticipated expiration: 2037-11-24
Also published as: CN108091973A

Abstract

The invention discloses a miniaturized broadband power distribution network, comprising: the shell is provided with a plurality of layers of printed boards inside; at least two Wilkinson power dividers, wherein each Wilkinson power divider is printed on the multilayer printed board in a layering way, and a plurality of floor layers are correspondingly arranged between each pair of Wilkinson power dividers; and the output end of the balun structure is correspondingly connected with the input port of each Wilkinson power divider and feeds power to each Wilkinson power divider. The invention has the advantages of lower loss on broadband, simple structure, small volume, convenient processing and good practicability.

Description

Miniaturized broadband power distribution network

Technical Field

The invention relates to equipment in the field of wireless communication and radar, in particular to a miniaturized broadband power distribution network, and more particularly to a power distribution network capable of realizing multi-path broadband power distribution in a relatively small size range.

Background

The power divider network is a multi-port microwave device, one path of microwave signal is distributed to multiple paths of channels, which is a very important component in the field of microwave technology all the time, and with the continuous development of microwave technology, increasingly higher requirements are provided for the miniaturization and broadband characteristics of the power divider.

As shown in fig. 1, a one-to-four microstrip power division network design is performed on the basis of the designed one-to-two broadband power divider. Namely, three one-in-two power dividers are used for cascade combination, but the occupied size is multiplied, and particularly, the broadband power divider with the working frequency covering the UHF/VHF frequency band is required.

Disclosure of Invention

The invention aims to provide a miniaturized broadband power distribution network, which is miniaturized by printing two broadband Wilkinson power distributors on the top layer and the bottom layer of a multilayer dielectric plate respectively and using a method of sharing a caliber. The power divider is fed by using the microstrip gradual-change balun, the balun structure converts unbalanced coaxial single-port feeding into balanced dual-port feeding, and meanwhile, the balun needs to have broadband performance. According to the uniqueness theorem and the angle-preserving transformation rule, the impedance of the parallel double lines is half of the impedance of the same-thickness microstrip line, and a proper impedance transformation structure is selected to realize the matching between the parallel double lines with the thickness h of the two substrates and the microstrip line with the thickness h of the substrates, so that the insertion loss of the power distribution network is reduced.

In order to achieve the above purpose, the invention is realized by the following technical scheme:

a miniaturized broadband power distribution network, comprising: the shell is provided with a plurality of layers of printed boards inside; at least two Wilkinson power dividers, wherein each Wilkinson power divider is printed on the multilayer printed board in a layering way, and a plurality of floor layers are correspondingly arranged between each pair of Wilkinson power dividers; and the output end of the balun structure is correspondingly connected with the input port of each Wilkinson power divider and feeds power to each Wilkinson power divider.

Preferably, the broadband power distribution network is further provided with a transition structure, the transition structure is a transition structure of a parallel double-line structure to a micro-strip line structure, and an input end of the transition structure is connected with an output end of the balun structure; the output end of the power divider is connected with the input port of each Wilkinson power divider.

Preferably, the balun structure is a microstrip gradual change balun structure, and the output end of the balun structure is a parallel double-line structure matched with the input end of the transition structure.

Preferably, an input end of each wilkinson power divider is a microstrip line structure, and the input end of each wilkinson power divider is matched with an output end of the transition structure.

Preferably, the broadband power distribution network is further provided with SMP adapter ports matched with the wilkinson power dividers, and the SMP adapter ports are correspondingly connected with the output ends of each wilkinson power divider respectively.

Compared with the prior art, the invention has the following advantages:

the power distribution network can realize smaller volume, and has more obvious advantages especially for the power distribution network with wider working frequency band and low frequency band coverage and the power distribution network with larger scale. Lower loss over a wide frequency band can be achieved. Simple structure and convenient processing. Has good practicability.

Drawings

Fig. 1 is a schematic diagram of a conventional miniaturized broadband power distribution network;

fig. 2 is a schematic diagram of a miniaturized broadband power distribution network according to the present invention;

fig. 3 is a schematic diagram of a miniaturized broadband power distribution network according to the present invention;

FIG. 4 is a diagram illustrating return loss of an exemplary miniaturized broadband power distribution network according to the present invention;

fig. 5 is a schematic diagram of insertion loss of an example of a miniaturized broadband power distribution network according to the present invention.

Detailed Description

The present invention will now be further described by way of the following detailed description of a preferred embodiment thereof, taken in conjunction with the accompanying drawings.

As shown in fig. 2 and 3, a miniaturized broadband power distribution network according to the present invention includes: the power distribution device comprises a shell 1, a multilayer printed board 4 arranged in the shell 1, a first Wilkinson power divider 2 and a second Wilkinson power divider 3 which are respectively arranged at the top layer and the bottom layer of the multilayer printed board 4, and a floor layer 5 correspondingly arranged between the first Wilkinson power divider 2 and the second Wilkinson power divider 3;

the output end of the balun structure 6 is connected with the input end of the parallel double-line-to-microstrip line transition structure 7, in the embodiment, the balun structure 6 is a microstrip gradual change type balun structure, and the output end of the balun structure 6 is a parallel double-line structure; the input ends of the first Wilkinson power divider 2 and the second Wilkinson power divider 3 are of microstrip line structures, and are matched through the parallel double-line-to-microstrip line transition structure 7, so that the first Wilkinson power divider 2 and the second Wilkinson power divider 3 can be connected, namely the input ends of the first Wilkinson power divider 2 and the second Wilkinson power divider 3 are connected with the output end of the parallel double-line-to-microstrip line transition structure 7; thereby to obtain

The single-port power of the balun structure 6 is divided into two paths to feed the input ports of the first Wilkinson power divider 2 and the second Wilkinson power divider 3 respectively.

Two pairs of Symmetrical Multi-processing (SMP) switching ports 8 are symmetrically arranged and respectively connected with the output ends of the first wilkinson power divider 2 and the second wilkinson power divider 3.

In this embodiment, the single-node wilkinson power divider belongs to a narrow-band structure, and in order to further widen the operating band, a plurality of sections of wide-band power dividers may be used, the order of the power divider is determined according to the bandwidth of the power divider, and then table lookup is performed to obtain the length and the width of each section of normalized impedance converted into a microstrip line. The seven-section Wilkinson power divider is realized in a frequency band range of 0.4GHz-4.5GHz, the return loss is less than-15 dB, the insertion loss is less than 4.5dB, and the isolation is greater than 18 dB.

The balun structure 6 of the broadband is realized through a hyperbolic gradual change structure, and the hyperbolic gradual change impedance converter can be equivalent to a step impedance converter with infinite step number, so that the broadband is realized, and the miniaturization of the broadband-based balun structure is facilitated.

In the present embodiment, the dielectric substrate of the multilayer printed board 4 model FR4 has a relative dielectric constant of 4.6 and a substrate thickness h of 2.4 mm.

In this embodiment, the balun structure 6 may be a broadband balun for switching from 50 Ω unbalanced feed to 100 Ω balanced feed, and has a return loss of less than-15 dB and an insertion loss of less than 0.7dB in a frequency band range of 0.4GHz to 10GHz, and an insertion loss of less than 0.5dB in a frequency band range of 0.4GHz to 4.5GHz, which is less than 1dB less than the insertion loss of a common-frequency one-by-two power divider.

In this embodiment, since the balun output end is a parallel double-line structure, and the wilkinson power divider input end is a microstrip line structure 7, according to the uniqueness theorem and the conformal transformation rule, the impedance of the parallel double-line is half of the impedance of a microstrip line with the same thickness and width as the first half, when the parallel double-line and the microstrip line have the same line width, the impedance of the microstrip line is only half of the impedance of the parallel double-line, which is 50 Ω, and the parallel double-line and the microstrip line are severely mismatched;

in the present embodiment, in order to reduce the matching loss, the transition structure 7 employs a λ/4 impedance transformer, where λ represents the broadband center frequency wavelength; an impedance transformation of 100 omega to 50 omega is achieved. Meanwhile, due to the ground-free structure of the parallel double lines, in order to reduce the influence of the floor on the parallel double lines, the width of the transition structure floor is set to be 3-5 times of the line width of the microstrip line. The insertion loss of the transition structure 7 in the operating frequency band is less than 0.6 dB.

In summary, the two one-to-two wilkinson power dividers are placed in a common aperture to achieve miniaturization, the power dividers are fed through the balun structure, the transition structure is simulated and optimized, and a broadband miniaturized one-to-four power divider network can be obtained.

As shown in fig. 4 and 5, the present application implements a miniaturized power distribution network in the frequency band range of 0.4GHz to 4.5 GHz. Within the working frequency band, the return loss is below-15 dB, and the typical insertion loss value is 7.5 dB.

While the present invention has been described in detail with reference to the preferred embodiments, it should be understood that the above description should not be taken as limiting the invention. Various modifications and alterations to this invention will become apparent to those skilled in the art upon reading the foregoing description. Accordingly, the scope of the invention should be determined from the following claims.

Claims

1. A miniaturized broadband power distribution network, comprising: the shell is provided with a plurality of layers of printed boards inside;

at least two Wilkinson power dividers, each of which is printed on the multilayer printed board in layers,

a plurality of floor layers correspondingly arranged between each pair of Wilkinson power dividers;

the output end of the balun structure is correspondingly connected with the input port of each Wilkinson power divider and feeds power to each Wilkinson power divider;

the broadband power distribution network is further provided with a transition structure, the transition structure is a transition structure for converting a parallel double-line structure into a micro-strip line structure, and the input end of the transition structure is connected with the output end of the balun structure; the output end of the power divider is connected with the input port of each Wilkinson power divider;

the balun structure is a micro-strip gradual-change balun structure, and the output end of the balun structure is a parallel double-line structure matched with the input end of the transition structure.

2. A miniaturized broadband power distribution network according to claim 1,

the input end of each Wilkinson power divider is of a microstrip line structure, and the input end of each Wilkinson power divider is matched with the output end of the transition structure.

3. A miniaturized broadband power distribution network according to claim 1,

the broadband power distribution network is further provided with SMP (symmetric multi-processing) switching ports matched with the Wilkinson power dividers and correspondingly connected with the output ends of the Wilkinson power dividers respectively.