RU216829U1 - SMALL BROADBAND UHF ANTENNA - Google Patents

Abstract

The utility model relates to radio communications, namely to antennas with vertical polarization and a circular radiation pattern in the horizontal plane. The antenna is designed for portable radio stations and is installed on them using a high-frequency connector. A small-sized broadband antenna contains a high-frequency connector (1), a matching broadband transformer (2), an antenna emitter (3) made of tinned copper conductors twisted together in a braid with dimensions of 2×4×145 mm. The annular core of the transformer is made of magnetically soft thermostable ferrite with a magnetic permeability of 30. The winding on the annular core is made in two pairs of wire with a cross section of 0.12 mm ² in fluoroplastic insulation (4, 5). The length of each wire in both pairs is not more than 60 mm. The first pair is wound with parallel wires, turn to turn on one side of the ring core, the number of turns is 2. The second pair is wound on the opposite side of the ring core with wires twisted together, the number of turns in the twist is 10. The technical result consists in creating an antenna design that provides a coefficient standing wave (SWR) no more than 3.0 and gain (Ku) from minus 4 dBi to plus 4 dBi in the range of 220 - 1000 MHz, with an antenna height of less than 200 mm. 1 w.p. f-ly, 4 ill.

Description

The utility model relates to radio communications, namely to antennas with vertical polarization and a circular radiation pattern in the horizontal plane. Can be used with portable radios as a transmitting and receiving antenna.

From the prior art, a wide-range antenna with a reactive insert is known, containing a linear radiator, in the upper part of which a reactive insert is placed, a base with a connector and a coupling transformer, characterized in that the reactive insert is made in the form of an inductor shunted by a resistor, and the coupling transformer is installed or before the connector, or after the connector (Patent RU 25815, IPC H01Q 9/00, published 10/20/2002).

This well-known antenna device is the closest analogue of the claimed device.

The disadvantage of this technical solution is the presence of a resistor that dissipates part of the energy into heat, thus reducing the efficiency of the antenna.

The objective of the claimed technical solution is to create a small-sized antenna having a wide frequency range with minimal losses in the matching device, which does not contain a resistor that reduces the efficiency of the antenna.

The technical result consists in creating an antenna design that provides a standing wave ratio (SWR) of not more than 3.0 and a gain (Ku) from minus 4 dBi to plus 4 dBi in the range of 220 - 1000 MHz, with an antenna height of less than 200 mm.

The problem is solved, and the specified technical result is achieved due to the fact that a small-sized broadband antenna contains a high-frequency connector consisting of a central contact and a housing, a matching broadband transformer containing a winding of wires on a ring core, a central contact for connecting to a high-frequency connector, contact for connection to the housing, contact for connection to the emitter. According to the utility model, the antenna emitter is made of tinned copper conductors twisted together in a braid with dimensions of 2 × 4 × 145 mm, on the ring core of the transformer, made of magnetically soft thermostable ferrite with a magnetic permeability of 30, winding is made in two pairs of wire with a cross section of 0.12 mm ² in fluoroplastic insulation, the length of each wire in both pairs is not more than 60 mm, the first pair is wound with parallel wires, turn to turn on one side of the ring core, the number of turns is 2, the second pair is wound on the opposite side of the ring core with wires twisted together, the number of turns in a twist - 10.

An additional embodiment of the device is possible, in which:

- transformer (2) can be made on 2-ring ferrite cores tightly connected to each other (Fig. 2).

In the following, the utility model is explained with reference to the figures, where:

in fig. 1 shows a sketch of the design of the antenna;

in fig. 2 schematically shows the design of the transformer;

in fig. 3 shows the measured SWR of the antenna;

in fig. 4 shows the measured antenna gain.

A small-sized broadband antenna contains a high-frequency connector, consisting of a central contact and a housing (1), a matching broadband transformer (2), an emitter (3) (figure 1).

A transformer (2) is connected to the central contact of the high-frequency connector (1) with the “C” output. An emitter (3) is connected to the output "A" of the transformer (Fig. 2) (Fig. 1).

A matching broadband transformer contains a winding of parallel wires (4), a winding of wires made of twisted pair (5) on a ring core made of magnetically soft thermostable ferrite with a magnetic permeability of 30, a central contact for connecting to a high-frequency connector (C), a contact for connecting to body (K), contact for connection to the emitter (A) (Fig. 2).

Contact "C" is connected to the central contact of the high-frequency connector (1) output "Sch" (Fig. 1, 2).

Contact "K" is connected to the body of the high-frequency connector (1) output "1K" (Fig. 1, 2).

Contact "A" is connected to the emitter (3) output "3A" (Fig. 1, 2).

Winding is carried out in two pairs of wire with a cross section of 0.12 mm2 in fluoroplastic insulation. The length of each wire (B) in both pairs is not more than 60 mm (Fig. 2).

The first pair (4) is wound with parallel wires, winding to winding on one side of the ring core. The number of turns - 2 (Fig. 2).

The second pair (5) is wound on the opposite side of the annular core with wires twisted together, the number of turns in the twist is 10 (Fig. 2).

The emitter is made of tinned copper conductors twisted together in a braid with dimensions of 2×4×145 mm (3).

The device works as follows.

The antenna is mounted to the radio by attaching the RF antenna connector (1) to the radio's antenna connector. When the radio station is switched on in the transmission mode, the signal from the output of the radio station's power amplifier enters the antenna through the central contact of the high-frequency connector (1). Further, the signal passes through the transformer winding (2) made by parallel conductors (4) and arrives at the antenna emitter (3), from which the radio wave is then emitted. At the same time, due to the fact that the transformer has a feedback loop of wires twisted into a twisted pair (5), a system is created that compensates for parasitic currents, which also contributes to an increase in the broadband matching qualities of the transformer (2). Due to the need to use ferrite in the transformer to expand the matching band, the antenna has a transmitter power limit of up to 3 watts. Due to the absence of resistive elements in the matching system, a high antenna efficiency is ensured.

The transformer core (2) in this case is not used as a magnetic circuit for currents in the antenna radiator, unlike other transformers with a ring core. It serves to stop parasitic currents outside the twisted (5) and parallel pair (4). Since pairs of wires (4, 5) are wound around the core, sufficient inductance can be obtained with its small dimensions, unlike, for example, a transformer on coaxial cable segments.

Convenience and assembly quality is achieved due to the reliability of the connection of all structural elements, as well as due to the possibility of element-by-element assembly itself in a rational technological process.

The most successfully claimed UHF small-sized broadband antenna is used for communication between portable radio stations.

Claims (2)

1. A small-sized broadband antenna containing a high-frequency connector consisting of a central contact and a housing, a matching broadband transformer containing a winding of wires on an annular core, a central contact for connecting to a high-frequency connector, a contact for connecting to a housing, a contact for connecting to an emitter, different the fact that the emitter is made of tinned copper conductors twisted together in a braid with dimensions of 2 × 4 × 145 mm, on the ring core of the transformer, made of magnetically soft thermostable ferrite with a magnetic permeability of 30, winding is made in two pairs from a wire with a cross section of 0.12 mm ² in fluoroplastic insulation, the length of each wire in both pairs is not more than 60 mm, the first pair is wound with parallel wires, turn to turn on one side of the ring core, the number of turns is 2, the second pair is wound on the opposite side of the ring core with wires twisted together, the number of turns in twist - 10 . 2. A small-sized broadband antenna according to claim 1, characterized in that the transformer can be made on 2-ring ferrite cores tightly connected to each other.

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