RU2843513C1 - Small-sized helical ultra-wideband antenna - Google Patents

Abstract

FIELD: antenna equipment.

SUBSTANCE: invention relates to antenna engineering and specifically to helical antennae operating in 1-18 GHz frequency range. Proposed is a small-sized helical ultra-wideband antenna comprising a metal housing in which a resistance transformer with a connector is located, consisting of a shield with a flange fixed to the metal housing by means of fastening screws, from central core, on which coaxial-waveguide line is located, inserted into screen with flange, wherein one end of resistance transformer with connector is connected to receiving-transmitting circuit, and the other end of the resistance transformer with a connector is connected to the antenna spiral through the inner diameter, characterized in that the antenna spiral is made in the form of a non-uniform Archimedean spiral located on a dielectric substrate mounted in a metal housing and fixed to it by rivets, and inside the metal housing there is an absorber with a dielectric insert mounted thereon, wherein non-uniform Archimedean spiral by ends on outer diameter through resistors is connected to outer conducting periphery of metal housing.

EFFECT: stability of amplitude and phase parameters of an output antenna signal in the whole range of frequencies.

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Description

The invention relates to antenna technology, namely to helical antennas operating in the frequency range from 1 GHz to 18 GHz as part of antenna systems for various purposes, in particular in detection, direction finding and tracking systems.

The requirements for broadband and miniature size are often imposed on radio engineering systems for direction finding and tracking. In many modern systems for direction finding of radiation sources, radio monitoring and radio surveillance systems, a wide operating frequency band and reception of signals with arbitrary polarization are provided by using spiral antennas. The broadband of antennas is determined by the requirements for matching (standing wave ratio), the shape and width of the radiation patterns, and the magnitude of the gain in the operating frequency range. Spiral antennas are weakly directional antennas of elliptical and controlled polarization and can be used as independent antennas or as part of antenna arrays.

To reduce the overall dimensions of the antenna and achieve broadband, the space between the spiral and the bottom of the reflector is filled with dielectric materials. It is known that the propagation of electromagnetic waves in a dielectric leads to their slowing down and to a shortening of the wavelength, compared to the wavelength in free space (Ultra-wideband antennas (collection of articles): trans. from English / trans. S.V. Popov, V.A. Zhuravlev. Edited by L.S. Benenson. - Moscow: Mir, 1964. - 464 pp.).

The "Small-sized ultra-wideband helical antenna" is known (patent RU 2790277 C1, published 15.02.2023). The antenna contains a combined two-way helix, a dielectric housing with a hemispherical helix placed on it, a matching balun transformer and metal reflectors. When implementing the known invention, the gain in the lower part of the operating frequency range increases and the antenna ranges are expanded to lower frequencies. However, this solution cannot ensure the formation of a signal with a stable value of the radiation pattern at the transition of the properties of the electromagnetic wave and with the absence of phase center drift in the entire operating frequency range from 1 GHz to 18 GHz.

The prototype is a strip helical antenna published in the source "The Sinuous Antenna in Dual Polarized Configuration". Mohammad Vahdani. Low-profile, Ultra-Wideband and Dual Polarized Antennas and Feeding Systems [Electronic resource], https://pastel.archives-ouvertes.fr), published 18.06.2010). The antenna contains a metal case, which contains a resistance transformer with a connector, consisting of a screen with a flange, and a central core, on which a coaxial-waveguide line is located, inserted into the screen with a flange. The disadvantage of the prototype is that the strip helical antenna does not provide a stable value of the radiation pattern at the transition of the properties of the change in the electromagnetic wave and a stable position of the phase center over the entire operating frequency range, is not compact and ultra-wideband.

The technical problem is that the known helical antennas do not provide stability of the output antenna parameters for consumers of the receiving signal of detection, direction finding and tracking systems in the entire operating frequency range from 1 GHz to 18 GHz.

The technical result of the claimed invention consists in improving the quality of the output antenna signal, providing consumers with stable amplitude and phase parameters in the entire operating frequency range.

In order to achieve the technical result, a small-sized spiral ultra-wideband antenna is proposed, comprising a metal housing, in which a resistance transformer with a connector is located, consisting of a screen with a flange, fixed to the metal housing using fastening screws, from a central core, on which a coaxial-waveguide line is located, inserted into the screen with a flange, wherein one end of the resistance transformer with a connector is connected to the transmitting and receiving path, and the other end of the resistance transformer with a connector is connected to the antenna spiral through the inner diameter, wherein the antenna spiral is made in the form of an uneven Archimedean spiral located on a dielectric substrate installed in the metal housing and fixed to it using rivets, and an absorber with a dielectric insert installed on it is located inside the metal housing. In this case, the uneven Archimedean spiral is connected with its ends on the outer diameter through resistors to the outer conductive periphery of the metal housing.

The metal body and dielectric substrate of the small-sized spiral ultra-wideband antenna have technological openings for the possibility of installing the antenna on the carrier object.

The invention is illustrated by figures.

Fig. 1 shows a small-sized ultra-wideband helical antenna with overall dimensions.

Fig. 2 shows a small-sized ultra-wideband helical antenna in section.

In Fig. 1-2 the following notations are introduced:

1. The antenna spiral is in the form of an uneven Archimedean spiral.

2. Dielectric substrate.

3. Metal body.

4. Rivets.

5. Technological holes.

6. Dielectric insert.

7. Absorber.

8. Resistors.

9. Screen with flange of resistance transformer with connector.

10. Coaxial-waveguide line of impedance transformer with connector.

11. Central core of the resistance transformer with connector.

12. Mounting screws.

13. External conductive periphery of the metal housing.

14. Transmitting and receiving path.

The essence of the declared antenna

A spiral antenna may have several branches (leads) of the spiral. Depending on the ratio of the spiral diameter to the wavelength, the radiation pattern may be axial or conical. An uneven Archimedean spiral is characterized by a smooth change in the diameter of the spiral wire. In accordance with the purpose of the antenna, it is necessary to ensure its unidirectional radiation, for which a metal screen and absorbing layers are included in the antenna design. For the same purpose, the ends of the conical spiral are loaded on matching resistances.

To achieve the technical result, the design of the small-sized ultra-wideband helical antenna included an antenna helix in the form of an uneven Archimedean spiral 1, located on a dielectric substrate 2, which is installed in a metal housing 3 and fixed to it using rivets 4.

One end of the resistance transformer with a connector is connected to the antenna spiral in the form of an uneven Archimedean spiral 1 through the internal diameter, the other end of the resistance transformer with a connector is connected to the transmitting and receiving path 14.

The resistance transformer with a connector consists of a screen with a flange 9, secured to a metal housing 3 using fastening screws 12, and a central core 11, on which a coaxial-waveguide line 10 is located, which are inserted into the screen with a flange 9.

The uneven Archimedean spiral is connected with its ends on the outer diameter through resistors 8 to the outer conductive periphery 13 of the metal housing 3. Also in the inner part of the metal housing 3 there is an absorber 7 with a dielectric insert 6 installed on it, while in the metal housing 3 and in the dielectric substrate 2 there are technological openings 5 for the possibility of installing the antenna on the carrier object.

In a connector-type impedance transformer, the flanged shield provides grounding, the center core provides the main signal path, and the coaxial waveguide line provides insulation between the center core and the flanged shield.

The transmitting and receiving path is intended for receiving (transmitting) the main signal to (from) it, and the antenna spiral, fed by a resistance transformer with a connector, is intended for receiving (transmitting) the main signal to (from) it from the surrounding space (or into the surrounding space).

Absorber layers with a strictly defined value of permittivity ε are intended to equalize the electrodynamic characteristics and parameters of the antenna in the entire frequency range from 1 GHz to 18 GHz, where the lower frequency of 1 GHz is limited by the diameter of the antenna spiral, and a dielectric insert with a strictly defined value of permittivity ε, installed on the absorber layers, additionally equalizes the electrodynamic characteristics and parameters of the antenna in the lower frequency range from 1 GHz to 4 GHz.

By connecting the uneven Archimedean spiral with its outer diameter through resistors to the outer conductive periphery of the metal body, grounding and normalization of the standing wave ratio at lower frequencies of the antenna occurs.

This ensures the formation of a signal with a stable value of the directional diagram, including at the transition of the boundaries of change in the physical properties of the electromagnetic wave with the absence of drift of the phase center over the entire operating frequency range from 1 GHz to 18 GHz, which, as a result, leads to ultra-wideband (the frequency range overlap is 18:1=18) and small dimensions.

The small-sized ultra-wideband helical antenna provides the formation of a signal with a stable value of the directional pattern, including at the transition of changes in the physical properties of the electromagnetic wave with the absence of phase center drift in the entire operating frequency range from 1 GHz to 18 GHz, providing ultra-wideband and small dimensions.

Claims (2)

1. A compact spiral ultra-wideband antenna comprising a metal housing in which a resistance transformer with a connector is located, consisting of a screen with a flange secured to the metal housing using fastening screws, from a central core on which a coaxial waveguide line is located, inserted into the screen with a flange, wherein one end of the resistance transformer with a connector is connected to the receiving and transmitting path, and the other end of the resistance transformer with a connector is connected to the antenna spiral through an internal diameter, characterized in that the antenna spiral is made in the form of a non-uniform Archimedean spiral located on a dielectric substrate installed in the metal housing and fixed to it using rivets, and an absorber with a dielectric insert installed on it is located inside the metal housing, wherein the non-uniform Archimedean spiral is connected with its ends on the external diameter through resistors to the external conductive periphery of the metal housing. 2. An antenna according to item 1, characterized in that the metal housing and the dielectric substrate have technological openings to enable the installation of the antenna on the carrier object.