RU2334312C1 - Power divider - Google Patents

Abstract

FIELD: electricity.

SUBSTANCE: power divider contains rectangular metal body, three slots, metal frame, metal base, aluminum board with coated from one side topological pattern of power divider, four resistors and dielectric patch of equal thickness. Metal base of divider is implemented in the shape of board, sputtered at both sides and at ends, on which from one side there are fixed dielectric patches. Internal chamber of body is divided by step for two parts, where bottom part has width and length dimensions equal to width and length of metal frame, which is mounted and fixed on step, furthermore on frame metal base fixed by side opposite to that one, where dielectric patches are fixed. At dielectric patches aluminum board mounted by side opposite to that one which is with topological pattern. Boards form asymmetrical suspended line.

EFFECT: providing of power divider running and losses reduce with rising of operating frequency.

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Description

The invention relates to a microstrip technique of electronic devices. Designed to split the power into two channels in a wide frequency band. It is used in radio receivers, as well as in measuring equipment.

A known scheme for dividing power into several channels, designed for transmitting devices (RU Pat. No. 2121734, Н01Р 3/08, Bull. No. 31 of 11/10/98.), Performed on the lines in a structure close to a symmetrical microstrip line (MPL). The circuit consists of two metallized base planes, between which a thin intermediate dielectric layer with a strip structure of conductors is inserted. The space between the intermediate dielectric layer and two bases is filled with the first and second dielectric layers. Inside these dielectric layers, cavities are made under the metal strips of the intermediate dielectric. By introducing these cavities, a reduction in power losses in the first and second dielectric layers is achieved.

The disadvantage of this scheme is the presence of a line of the type symmetrical, which in receivers is used in rare and very special cases. Usually asymmetrical lines are used in receivers because of the convenience of mounting elements. In asymmetric microstrip lines, losses are due to the technology of deposition of metal layers, losses in the dielectric play a lesser role. Losses in the metal layer together with the technological sublayer in thin-film technology are higher than in thick-film technology, but thin-film technology is more accurate, which is essential for moving the divider to the high-frequency region.

Known ring power dividers, made on quarter-wave segments of the transmission line (Reference for elements of strip technology edited by A.L. Feldstein. M .: Communication, 1979, p.168). A divider of this type is taken as a prototype of the invention and contains: a rectangular metal case, three connectors, a metal frame, four resistors, a metal base, a polycor core board with a topological pattern of a power divider printed on one side, and the other side is metallized, which serves as a metal base. The topological drawing contains an input and two output arms, four pairs of quarter-wave segments of lines connected in series (Fig. 1). The input arm of the power divider is connected to the inputs of the first pair of quarter-wave segments, and the output arms are connected to the outputs of the fourth pair of quarter-wave segments. Resistors are connected to the outputs of each pair of quarter-wave line segments. One connector is mounted on the end surface of the housing, and the other two on its opposite side surfaces. The external conductors of the connectors are connected to the housing. The inner conductor of the end connector is connected to the input arm of the topological pattern of the power divider. The inner conductors of the side connectors are connected to the output arms of the topological pattern of the power divider. The metal frame is fixed in the cavity of the housing.

One of the drawbacks of such dividers made on an asymmetric microstrip line on a multicore circuit board with metallization of one surface is a significant increase in losses with an increase in the operating frequency, which makes them inapplicable at frequencies above 10-12 GHz. The second drawback is the high value of the effective dielectric constant for an asymmetric microstrip line, and a large shortening of the wavelength (n ~ 2.6). The third disadvantage of the prototype is the difficulty of implementing resistors of small geometric dimensions with the required large differential values for broadband dividers.

Insofar as:

- quarter-wave line segments at the indicated frequencies have a length of less than 3 mm, while it is impossible to create a ring structure;

- losses in the MPL at frequencies of 10-12 GHz of such a design become unacceptably large;

- shortening the wavelength with increasing frequency requires an increase in manufacturing accuracy, which is achieved in thin-film technology, and the use of a divider in a wide band requires resistors with a large difference in resistance values, the manufacture of which in thin films causes technological difficulties.

The inability to use the ring structure in the high part of the frequency range is overcome by switching to dividers on the connected lines, which are known, however, there are still restrictions on the losses and differential values of the resistors.

The technical result of the invention is to ensure the operation of the power divider in a wide band of high frequencies, more than two octaves (in the example implementation from 4 to 18 Hz) and reduce losses.

The invention and its work are illustrated by drawings.

Figure 1 presents a diagram of the topology of the divider prototype.

Figure 2 presents sketches of the projections of the power divider (2A is a bottom view, 2b is a section in the plane of symmetry, 2B is a top view).

Figure 3 shows the topology of the conductors on the front side of the multicore board for an asymmetric suspended line (a board without a metal screen on the back side) of a power divider on four pairs of connected lines, designed to operate in the frequency band 4-18 GHz.

Figure 4 presents a sketch of the connection of the suspended line with the connector.

Figure 5 presents a sketch of a metal base made on a multicore PCB metallized on both sides and at the ends with fixed dielectric plates.

Figure 6 presents a sketch of the connection of the asymmetric microstrip line with the connector.

1-6, the designations are introduced: case 1, connector 2, multicore board 4, board 5 metallized along planes and ends, input arm of the divider 6, output arms 7 and 8 of the divider, pairs of quarter-wave segments of connected lines 9-12, metal jumpers 13 from the central conductor of the connectors to the input and output arms of the power divider, dielectric sleeve 14, dielectric pads 15 of equal thickness deposited on a metallized board, microstrip board 16 with an asymmetric MPL, a metal jumper 17 with a metallized reverse side of the board on the metal wall of the housing near the connector input (for Prototype), R1 resistors, R2, R3 and R4.

Power divider design description

The technical result of the invention is achieved due to the fact that the proposed power divider (Fig. 2) contains: a metal case 1 with three connectors 2, a metal frame 3, a polycorboard 4 with a topological pattern of a power divider applied on one side (Fig. 3), forming a power divider into two channels, a metal base 5, made in the form of a multicore plate with metallization on two sides and ends, four pairs of quarter-wave segments of connected lines 9-12, metal jumpers 13, three dielectric bushings of fluorine layer 14, dielectric pads 15, four resistors with ratings R1 = R4 = 120 Ohms, R2 = R3 = 240 Ohms.

The topological drawing of the power divider contains an input arm 6 and two output arms 7 and 8 and four pairs of connected quarter-wave segments of lines 9-12 connected in series (Fig. 3). The input arm 6 is connected to the input of the first pair of quarter-wave segments 9, and the output arms are connected to the outputs of the fourth pair of quarter-wave segments 12. Resistors R1, R2, R3 and R4 are connected to the outputs of each pair of connected quarter-wave segments 9-12 lines, respectively.

One connector 2 is fixed on the end surface of the housing 1, and two others, on its opposite side surfaces. The external conductor of the connectors is connected to the housing. The inner conductor of the end connector is connected to the input arm 6 of the topological pattern of the power divider. The inner conductors of the side connectors are connected to the output arms 7 and 8 of the topological design of the power divider.

The internal cavity of the housing 1 is divided by a step into two parts, the lower part has dimensions of width and length equal to the width and length of the metal frame 3, which is mounted and mounted on the step. On the frame 3, a metal base 5 is attached with the side opposite to that on which the dielectric pads 15 are fixed (Figs. 4 and 5). On the dielectric plates, a multicorrosive board is fixed with 4 sides, the opposite side with a topological pattern. Dielectric bushings 14 are placed at the input of the internal conductors of the connectors 2 (figure 4). Pairs of quarter-wave line segments are made connected.

The housing 1 is made of metal in the form of a rectangular box with a step inside (figure 2) and with elements for fasteners protruding beyond the rectangular dimensions. The body cavity is divided into two parts: upper and lower. The width and length of the upper half of the cavity is slightly less than the width and length of the lower part, so a step forms on the inner walls. The width and length of the upper part of the case corresponds to the width and length of gluing boards 4 and 5. The width, length and configuration of the lower part corresponds to the dimensions of the frame 3.

Connectors 2 are made in the form of coaxial microwave connectors with a wave impedance of 50 Ohms and are mounted on the housing 1: one on the front end wall of the housing, the other two symmetrically on opposite side walls (Fig. 2, a, b, c).

A rectangular metal frame 3 is mounted on a step in the lower part of the body cavity parallel to its base.

The board 4 is made of polycor, and the metal base is made of a polycor core, metallized on both sides and at the ends. They have a rectangular shape, width and length equal to the width and length of the upper part of the body cavity. The board 4 and the metal base 5 are located inside the case one above the other parallel to the base of the case on the frame 3 and are connected with glue applied to the dielectric plates 15 of the board 5, the dielectric plates are fixed so that they do not fall under the topological pattern of the divider (Fig. 4). Due to these overlays, a normalized gap is formed between the metal face of the board 5 and the bottom surface of the board 4 during gluing, forming an asymmetrical suspended line for the conductors of the board 4, which are applied on its front side. The conductors of the board 4 form a power divider into two channels with an input arm 6 and output arms 7 and 8, which are connected using metal jumpers 13 with the central conductors of the respective connectors 2.

The gluing of the boards 4 and 5 is soldered symmetrically along the bottom surface of the board 5 to the metal frame 3, which has overall dimensions larger than the rectangular dimensions of the gluing of the board 4 and 5. The configuration of the frame can be seen in figa. The frame 3, on the front surface protruding from under the gluing of the boards 4 and 5, is soldered to the step of the lower part of the body cavity 1. The configuration and dimensions of the frame correspond to the internal dimensions of the lower part of the body cavity.

Due to the metal base 5 and its connection to the frame 3, and the frame by soldering to the body 1, a reliable connection of the external conductor of the coaxial connector with the metal base of the suspended strip line is formed under the connector 2.

For a conventional asymmetric microstrip line, this connection is implemented differently by soldering a metal jumper 16 from the back metallized side of the board to a wall with a connector near its output (Fig.6).

Power divider operation

The power divider operates as follows (Fig.2, a, b, c and Fig.3). The broadband signal enters through the end connector 2 to the input arm 6 of the power divider and excites an even wave in four pairs of quarter-wave segments 9-12 connected lines. The even wave impedance on each segment of coupled lines is calculated in accordance with the impedance of a four-link ring power divider (prototype), so the broadband signal is divided into two lines, as in a conventional power divider.

When a broadband signal arrives at arm 7 or 8 in four pairs of quarter-wave segments 9-12 connected lines, an odd wave is excited, which travels respectively to arm 8 or 7 and determines the isolation between these arms. The impedance of the odd waves in the segments of the connected lines does not coincide with the impedance of the even waves, as is the case in the prototype. In this case, it was chosen 50 Ohm in all segments, therefore, the value of the absorption resistors differs from the value of the absorption resistors in the ring power divider (prototype): R1 = 103 Ohm, R2 = 173 Ohm, R3 = 292 Ohm and R4 = 482 Ohm, in which the difference in the values of the resistors is 4.8 times. In the proposed power divider, the resistors have the values: R1 = R4 = 120 Ohms, R2 = R3 = 240 Ohms. The difference in ratings is 2 times. The worst isolation in the experiment is 12 dB in the frequency range 4-18 GHz.

The graph shows the amplitude characteristic of the passage of power between channels 6 and 7 for the developed power divider with the topology shown in Fig.3.

The numbers in the top line of the graph correspond to the frequency in GHz at the starting point of the cell. The numbers next to the graph curve correspond to the maximum and minimum values in dB of the nearest graph points for the output arm 7.

General features of the invention and prototype

A rectangular metal case, three connectors, a metal frame, a metal base, four resistors, a multicore card with a topological pattern of a power divider on one side. The topological drawing contains an input and two output arms, four pairs of quarter-wave line segments connected in series. The input arm of the power divider is connected to the inputs of the first pair of quarter-wave segments, and the output arms are connected to the outputs of the fourth pair of quarter-wave segments. Resistors are connected to the outputs of each pair of quarter-wave line segments. One connector is mounted on the end surface of the housing, and the other two on its opposite side surfaces. The external conductors of the connectors are connected to the housing. The inner conductor of the end connector is connected to the input arm of the topological pattern of the power divider. The inner conductors of the side connectors are connected to the output arms of the topological pattern of the power divider. The metal frame is fixed in the cavity of the housing. The metallized base is connected to the housing near the connector.

An example of a specific implementation of the power divider

The width of the strips Wi and the gaps Si of the four segments of the connected lines for a 0.5 mm thick polycorboard and a 0.1 mm thick "suspension" of the screen for given even wave impedances corresponding to a conventional four-link ring power divider with an odd wave resistance of 50 Ohms for all segments are given in the table of geometric parameters of the power divider.

Table Line segments Zee
Even wave impedance W
Strip width S
Strip gaps Nee
Shortening the even wavelengths Lee
The length of the communication region for the even wave Zo
Impedance for connected segments R1 89.63 0.389 0.407 2,044 3.34 66,944 R2 77,175 0,501 0.598 2,037 3.34 62,118 R3 64,785 0.646 0.982 2,041 3.34 56,914 R4 55,785 0.646 1,2 2,047 3.34 52,813

Полоска сопротивлением 50 Ом имеет ширину 0,96 мThe value of the absorbing resistors R1 = R4 = 120 Ohms, R2 = R3 = 240 Ohms. They are realized using the density of surface resistance.

50 ohm strip has a width of 0.96 m

The height of the dielectric linings is 0.09 mm. The fluoroplastic dielectric sleeve in connectors 2 has an external diameter of 2 mm.

The developed design of a broadband power divider provides a technical result - dividing the power supplied to its input into two channels with an accuracy of ± 1.09 dB, with a channel isolation of at least 12 dB in the operating frequency range from 4 to 181 Hz.

Claims (1)

A power divider comprising a rectangular metal casing, three connectors, a metal frame, a metal base, four resistors, a multicore board with a topological pattern on one side of the power divider, which contains the input and two output arms, four pairs of quarter-wave line segments connected in series, the input arm is connected to the inputs of the first pair of quarter-wave segments, and the output arms are connected to the outputs of the fourth pair of quarter-wave segments, in addition, four resistors connected to the outputs of each pair of quarter-wave line segments, with one connector fixed to the end surface of the housing, and the other two on its opposite side surfaces, the outer conductors of the connectors connected to the housing, the inner conductor of the end connector connected to the input arm of the topological pattern of the power divider, and the inner conductors of the side connectors are connected to the output arms of the topological pattern of the power divider, and the metal frame is fixed in the cavity of the housing, characterized We note that four dielectric pads of equal thickness and three dielectric bushings are introduced, and the metal base is made in the form of a board metallized on both surfaces and at the ends, on which dielectric pads are fixed on one side so that they do not fall under the topological pattern of the divider, in addition , the internal cavity of the casing is divided by a step into two parts, the lower part has a width and a length equal to the width and length of the metal frame, which is mounted and fixed on the step, in addition, on the frame GSI base metal side opposite to that onto which the dielectric inserts, linings installed on dielectric board polycore side opposite to the topological pattern, dielectric sleeve arranged on the inner input conductors of connectors, moreover, a pair of quarter-wave line segments associated performed.

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