RU188485U1 - SMALL-SIZE SHORT-WAVE ANTEN FIDER DEVICE "MRV" - Google Patents

Abstract

The utility model relates to antenna technology. The antenna is made in the form of a circle of aluminum pipe, in the upper part of the gap; the circle is made of several segments that are interconnected by means of intersection inserts; a variable capacitor (KPI) is connected to the rupture of the circle due to end inserts; KPI is driven by a 12-volt electric motor (reversible); variable capacitor is enclosed in a radio transparent tube made of fiberglass pipe with a diameter of 200 mm. The technical result consists in the possibility of disassembling the antenna for compact transportation. 11 il.

Description

The utility model relates to antenna technology - small short-wave antennas (antennas with dimensions not exceeding twice the working wavelength and composed of electrically conductive active radiating elements - H01Q 9/04), and can be used by any organizations and departments in the creation and operation of radio communication systems KB (short wave). This device is an antenna in the form of a frame, and uses a new and unique scheme for applying energy to the antenna web (radiator).

Prerequisites for creating a utility model

The use of small frame antennas belongs to the earliest days of the radio. From their humble beginnings to today, framework antennas of various types, configurations and shapes have evolved and served many useful purposes. The most significant among them was the use of a framework antenna for direction finding. It should be noted that tuned loop antennas, having dimensions that are small relative to the wavelength, were used almost exclusively for reception purposes. The reasons for this limited use fall into two categories. Firstly, some types of frame antennas provide a significant improvement in the overall signal-to-noise ratio compared to other common types of antennas that receive industrial noise and man-made noise. Secondly, a practical scheme for applying energy to the antenna web was not available, which provides sufficient efficiency, simple tuning in a wide frequency range and impedance matching for most transmitting radio stations. The effectiveness of some types of loop antennas for receiving radio stations in the high frequency range and below has long been recognized as good. The popularity of these antennas stems from the simple fact that a small single-turn antenna demonstrates the characteristic that it almost completely responds to the magnetic component, being practically insensitive to the electrical component of the EMF of the same wave. In a normal radiation field (radio waves), the magnitude of the electric vector is 120 π larger than the magnitude of the magnetic vector, and the difference is due to internal impedance. However, the induction fields associated with artificial noise have components of the electric field that are many times greater than the components of the normal radiation field. Thus, a single-turn, tuned loop antenna, being essentially sensitive only to the magnetic field, provides a high degree of suppression of the reception of such noise in relation to the antenna, such as a dipole, which is sensitive to both the electrical component and the magnetic component of the wave field. At frequencies lower than 10 MHz, an improvement in signal-to-noise ratios over 20 dB of a relatively simple dipole is not uncommon when the receiving environment is used in serious sources of artificial noise.

Another important feature of compact frame antennas, which are an advantage over traditional vertical tuned pins or small tuned horizontal dipole antennas, is a unique radiation pattern. If the loop antenna is oriented so that the plane of the emitter is perpendicular to the earth and if it is placed at a height less than a quarter of the wavelength above the ground that has perfect conductivity, it will show almost uniform radiation at all angles from horizon to zenith in the plane of the loop. The energy emitted by such an antenna is vertically polarized in the horizon and horizontally polarized above the head (zenith angle) (figure 7). Thus, it can be seen that a small loop antenna has a distinctive feature - it has radiation during transmission and reception both at long distances (through a small angle of vertically polarized propagation) or at short and medium distances (through horizontally polarized propagation of an oblique incidence). For comparison, a tuned whip antenna is only useful for propagation with vertical polarization, as it has radiation at angles of 30-45 °. Thus, a whip antenna is only useful for communication at very short distances through propagation by the earth wave or at long distances through propagation by a reflected wave. A horizontal dipole antenna located at a height of not less than 1/2 the wavelength above the ground, demonstrates the maximum power at a certain angle of radiation relative to the ground. This means there is a “dead zone”. From the foregoing, it follows that a properly designed small, tuned loop antenna can find significant benefits as a general-purpose antenna system, in particular for mobile or on-board objects, roofs of urban buildings that require small sizes, which can be used for short, medium and long-haul radio paths

According to the principle of energy supply to the canvas, it is possible to present the electrical circuit of the antenna power as the circuit of a simple transformer having tuned primary and secondary windings. The primary winding - emitter 1, the secondary winding - power supply loop 7 (figure 1). In the claimed utility model, a small customized power loop is used, which fits inside a tunable external primary contour (emitter) and in the plane of the primary contour. The power loop is located along the inner edge of the radiator. The diameter of the supply loop is chosen so as to ensure the exact impedance of the antenna, at which the input impedance will be constant over a larger frequency range. This structure provides a much wider range of antenna tuning in frequency with higher efficiency and almost more constant impedance than classical antenna types, such as pin, dipole, triangle.

According to the tuning method, you can think of a good circuit tuned to a specific frequency, where L is the emitter 1 (figure 1), C is a variable capacitor (KPI) 6 (figure 1). To tune the antenna in frequency, you need to change the capacitance, by turning the ECC.

Closest to the claimed technical solution is a broadband custom transmitting loop antenna. U.S. Patent No. 3,588,905 of June 28, 1971.

This design has an ellipse emitter with a diameter of 1,524 m (5 feet, 1 foot = 0.3048 m), made of aluminum pipes from 7 to 12 cm thick (3-5 inches), vacuum KPE with a capacity of 25-1000 pF, which allowed to cover the range from 3 to 15 MHz.

The disadvantages of this design are:

- the emitter tube is too thick - computer simulations showed that the efficiency of the antenna, with a radiator thickness of 30 mm, is optimal, with increasing thickness of the radiator, the antenna efficiency does not increase;

- the monolithic design of the radiator complicates the transportation of the antenna;

- use of a vacuum condenser - if the vacuum capacitor has a glass case, it can lead to glass breakage during transportation, as well as inefficient antenna operation at a lower frequency, using the maximum capacitor capacity (theoretical calculations and practice have shown that for antenna operation at low frequencies for a KB range, it is sufficient to have a capacitor capacitance from 25 to 550 pF);

- the fastening element of the power loop will not withstand a large wind load.

 The task, which the claimed device is designed to solve, is the ability to be quickly disassembled for transportation to a new installation site, to simplify the antenna design in principle and to integrate the antenna into the design of a full-featured device (except for the antenna, here is the mast and power cable, delay and control frequency tuning).

The design of the proposed utility model is a small-sized shortwave antenna-feeder device "MRV" (figure 1), consists of a small KB antenna (antenna type - magnetic frame), fiberglass mast, a set of braces, coaxial cable and power cable with connectors, control panel.

AFU “MRV” is an antenna-feeder device - Vladimirova Magnetic Frame.

The antenna consists of:

Emitter, in the form of a circle 1 (figure 1), which is made of aluminum pipe, with a diameter of 30 mm, a wall thickness of 2 mm, material - AD-31T, for ease of transportation, the radiator consists of several segments (figure 2), which are connected by intersection inserts (figure 3, 4). A capacitor of variable capacitance (KPI) with an air dielectric, the arrangement of plates in the form of a butterfly, and made of 1 mm sheet duralumin are inserted into the gap of the circle, the gap between the stator and rotor plates allows operation at reactive voltage up to 10 kV permissible radio power up to 150 watts. Fastened to the radiator elements using special crackers and end inserts. To protect against external influences (climatic, physical), the capacitor is located in a radio-transparent fiberglass tube 6 (figure 1), made of a fiberglass pipe with a diameter of 200 mm. The capacitor is driven by a motor with a voltage of 12 volts (reversible), the motor is controlled by the control panel (figure 6), which is located next to the operator, the signal from the console to the electric motor is fed through a two-wire cable, in double insulation.

Power loop 7 (figure 1), which is made of 50-ohm coaxial cable, for rigidity the cable is placed in a plastic pipe. The HDPE pipe is hermetically connected to the switching plastic box 4 (figure 1), in the bottom of which two connectors are embedded, one for connecting the high-frequency connector of the coaxial cable and the second for connecting the connector of the control cable. The box is provided with fastening elements to the pipe tube. At the top point, the power loop is attached to the pipe stand 3 (figure 1) with a special clip. The control cable from the plastic box to the electric motor passes inside the pipe tube 3 (figure 1).

The delays are attached to the pipe stand 3 (figure 1) with the help of a fastener attachment unit (figure 5). The material of the braces is a twisted Dan-line cord, 5 mm thick, with a tensile strength of 450 kg.

The antenna is connected to the transmitter or receiver using a feeder line (50 ohm coaxial cable), equipped with high-frequency connectors.

The whole antenna design is primed and painted with powder paint, except for the color we get a decorative and protective polymer coating.

In the form of a mast, a 2-meter fiberglass pipe stand with a diameter of 44 mm and a wall thickness of 6 mm is used.

The frequency range in which the antenna operates depends on the capacitance of the capacitor, the maximum capacitance of the capacitor is the lower limit of the operating frequency of the antenna, the minimal capacitance is the upper limit of the operating frequency of the antenna.

Small-sized short-wave antenna-feeder device "MRV" works as follows. Frequency tuning is performed by the operator. Switching the radio station to another frequency, the operator presses one of the buttons on the control panel (figure 6), which activates the electric motor KPI, and holds the button until the maximum noise appears in the speaker, or according to the maximum deviation of the arrow of the radio station (receiver) device - indicating the level received signal (if any). After setting up the reception, the operator conducts a radio communication session.

The technical result of this utility model is the ability to be disassembled for transportation to the installation site, the ability to work on the KB without the use of large areas and high masts; the ability to use the antenna as an ASI (antenna zenith radiation) only in the low-frequency sections of the KB band, which means an increase in the reliability of the KB radio in the so-called “dead zones”, does not require alignment of the antenna to the correspondent, since the antenna has a circular pattern, (Figure 7 ) shows that the antenna radiation in the horizon looks like a "eight", and there is at least 5-7 degrees (figure 8), this minimum can be defined only in the "near" zone (one wavelength), which allows you to avoid interference urban areas, the rest of the transmission paths (for repeated tests and inspections) radiation pattern - circular.

The technical result of the utility model is achieved by the fact that the compact shortwave antenna-feeder device "MRV" has the ability to be disassembled for transportation, due to the fact that the antenna is made in the form of a circle of aluminum pipe, which consists of segments interconnected by intersection inserts, and the antenna also has everything you need to work on the air on a KB (except for the radio station): the antenna itself, coaxial cable, fiberglass mast, drawbars, frequency tuning console, control cable and I.

Claims (1)

The antenna, made in the form of a circle of aluminum pipe, in the upper part of the gap; the circle is made of several segments that are interconnected by means of intersection inserts; a variable capacitor (KPI) is connected to the rupture of the circle due to end inserts; KPI is driven by a 12-volt electric motor (reversible); variable capacitor enclosed in a radiotransparent tube made of fiberglass pipe with a diameter of 200 mm; voltage to the motor is supplied from the control panel via a two-wire cable, in double insulation (control cable), which is located next to the radio station operator; delays are attached to the pipe stand with the help of a fastener attachment unit; the antenna is connected to the transmitter or receiver using a feeder line (50 Ohm coaxial cable with connectors); the entire antenna design is primed and painted with powder paint, except for the color - decorative and protective polymer coating; In the form of a mast, a 2-meter fiberglass pipe stand is used.

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