RU2634331C1 - Ultra-wideband coaxial-microstrip transition - Google Patents

Abstract

FIELD: radio engineering, communication.

SUBSTANCE: coaxial-microstrip transition contains a metal case of cylindrical shape with a central conductor. Co-axial to the longitudinal axis of the case, a through hole is made with a step-varying diameter. The central conductor, one end of which is made step-by-step, is pressed into a dielectric washer pressed into the inner sleeve pressed by the centering outer sleeve. Herewith the air coaxial transformer is formed by the steps of the case and the central conductor.

EFFECT: extending the range of operating frequencies towards microwave.

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Description

Application area

The invention can be used in the field of radar, radio navigation, communications, antenna-feeder systems and measuring equipment to create a reliable connection of coaxial and microstrip lines with a low level of transmission and return losses.

State of the art

Known coaxial-microstrip junction (US patent No. 3662318, 05/09/1972) containing a metal base, a dielectric substrate, on one side of which a current-carrying conductor is applied, and a coaxial connector, the central conductor of which is spring-loaded and connected to the current-carrying conductor.

Known coaxial strip junction OSM-244-4ASP (a guide to the calculation and design of microwave strip devices. / Under the editorship of V.I. Volman. M. Radio and communications, 1982, S. 211-213, Fig. 4.67a) selected for the prototype, comprising a housing that is an external conductor, an internal conductor, a dielectric sleeve, and the connection of the inner conductor with the MPL current-carrying conductor is carried out by glue.

The main disadvantage of these devices is the small range of operating frequencies.

SUMMARY OF THE INVENTION

The invention is aimed at solving a technical problem related to the possibility of improving the technical characteristics of a coaxial microstrip junction, as well as simplifying its mounting on a printed circuit board.

The technical result of the proposed solution is to expand the operating frequency range of the coaxial microstrip junction towards the microwave.

The technical result is achieved by the fact that in an ultrawideband coaxial-microstrip junction containing a metal housing with a central conductor, according to the proposed solution coaxially to the longitudinal axis of the housing, a through hole with a stepwise changing diameter is made, and the central conductor, one end of which is made in steps, is pressed into a dielectric washer, pressed into the inner sleeve, pressed by the centering outer sleeve, while the air coaxial transformer is formed by a step and the housing and the central conductor.

Brief Description of the Drawings

In FIG. 1 shows a top view of a coaxial microstrip junction, FIG. 2 shows a longitudinal section AA of the device, FIG. 3 shows a central conductor with a local cut in the region of lamellas, FIG. 4 shows a longitudinal section AA of a device with a printed circuit board; FIG. 5 shows a general view of a device with a printed circuit board.

In FIG. 1-3 indicated:

1 - metal case;

2 - the central conductor;

3 - dielectric washer;

4 - inner sleeve;

5 - the centering surface of the inner sleeve;

6 - external sleeve;

7 - internal threaded connection of the external sleeve;

8 - external threaded connection of the external sleeve;

9 - coaxial transformer;

10 - the first stage of the Central conductor;

11 - the second stage of the Central conductor;

12 - lamellas of the central conductor;

13 - reference plane of the connector;

14 - threaded holes;

15 - printed circuit board:

16 - plate;

17 - fixing screws.

The implementation of the invention

The invention is a two-port passive microwave device that converts T-waves of the coaxial line into quasi-T waves of the microstrip line, and vice versa, in a wide frequency range.

The coaxial microstrip transition of the coaxial design contains a metal housing 1 of a cylindrical shape coated with tin-bismuth, the inner cavity of which is the external conductor of the coaxial part of the transition. One end is a type I coaxial connector, the other end is connected to the printed circuit board 15. In the housing 1 coaxially to the longitudinal axis, an opening with a stepwise changing diameter is made. The central conductor 2, located in the housing 1, is made of beryllium bronze coated with gold. One end of the central conductor 2 is stepped and pressed into the dielectric washer 3. The first stage 10 of the central conductor 2 is the seating surface for the dielectric washer 3. The dielectric washer 3 is pressed into the inner sleeve 4 and acts as a support for the central conductor 2. The centering outer sleeve 6, screwed into the case, presses and centers the inner sleeve 4 on the cylindrical surface 4. The second stage 11 of the central conductor is the external conductor of the air coaxial transform 9, the torus formed by the steps of the housing 1 and the center conductor 2.

Installation of the transition to the printed circuit board is as follows.

The Central conductor 2 of the coaxial microstrip junction is connected to the current-carrying conductor of the microstrip line of the printed circuit board 15 by soldering. The transition is fixed on the printed circuit board 15 using a plate 16, pressed by fixing screws 17, screwed into the threaded holes 14, which are made in the end of the housing, perpendicular to its longitudinal axis.

The inventive ultra-wideband coaxial microstrip junction provides an operating frequency range from 0 to 50 GHz, reducing return and transmission losses, increasing the transmission coefficient and also simplifying the installation of the junction on a printed circuit board.

The following frequency dependences were obtained experimentally (two transitions connected “on the way” by a 2.5 cm long microstrip coplanar line made on Rogers 4350 V material):

- the transmission coefficient is not worse minus 4 dB;

- return loss in the frequency range from 0 to 40 GHz

no more than minus 24 dB, in the frequency range 40-50 GHz no more than minus 20 dB.

Claims (1)

An ultra-wide coaxial microstrip junction containing a cylindrical metal casing with a central conductor, characterized in that a through hole with a stepwise varying diameter is made coaxially with the longitudinal axis of the casing, the central conductor, one end of which is made in steps, is pressed into a dielectric washer pressed into the inner sleeve, pressed by the centering outer sleeve, while the air coaxial transformer is formed by the steps of the housing and the Central conductor .

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