RU158716U1 - TWO BAND ANTENNA - Google Patents

Abstract

1. A dual-band antenna consisting of a balancing device, a coaxial input / output, a conductive screen, an active vibrator that is fed through a balancing device from a coaxial input / output and is located above the conductive screen, holders, a protective casing, U-shaped shunts connected to the shoulders active vibrator and supplemented with idling loops, characterized in that the antenna is additionally equipped with two T-shaped shunts that are connected to the U-shaped shunts. 2. The dual-band antenna according to claim 1, characterized in that the active vibrator, U-shaped, T-shaped shunts, idle loops lie in the same plane and form a separate whole part. The dual-band antenna according to claim 1, characterized in that the active vibrator, U-shaped and T-shaped shunts, idle loops, a conductive screen, conductors of a balancing device, holders are made of sheet metal with the same processing method.

Description

The invention relates to antenna technology and can be used to amplify cellular signals in data transmission systems as a subscriber antenna.

A dual-band antenna No. 2183372 dated 12/19/1997 (published on 10.06.2002) is known from the prior art, which consists of an inductor, two rod-shaped radiating elements connected to opposite ends of the inductor, the dielectric material surrounding the inductor, part of the first radiating element, connected to one end of the inductor, and a portion of said second radiating element, connected to the other end of said inductor conducting rpusa surrounding dielectric material and confining coil portion and first and second radiating elements are connected to its respective ends. A conductive support housing surrounds the dielectric and supports the inductor and the connecting parts of the first and second radiating elements. The housing and the dielectric create a capacitance so that a resonant LC circuit is formed together with the inductor. The LC circuit is designed so that only one radiating element radiates in the higher frequency range of the two-band operating frequency range, while both radiating elements emit in the lower frequency range.

The disadvantages of the described device are:

- the presence of dielectric materials near the emitters and the power line, which leads to a decrease in antenna efficiency

- low gain

- the presence of concentrated elements that complicate the design.

As the closest prototype, consider a two-resonance antenna (patent No. RU 148192 dated 03.24.2014, option 2), consisting of an active vibrator located above the conductive screen, a balancing device, coaxial input / output or RF transmission line, screen, holders, protective casing comprising at least four passive vibrators. U-shaped shunts are connected to the shoulders of the active vibrator, supplemented by idle loops in such a way that additional vibrators are formed.

The disadvantage of the described device is:

- large antenna sizes;

- the complexity of the design due to the presence of a large number of components of the antenna.

The problem to which the claimed utility model is directed is to create an antenna with small dimensions, high adaptability, and a simplified design with the following characteristics:

1) Formation of unidirectional radiation;

2) Work in two frequency ranges LF and HF, the average frequencies of which differ by about 2 times, and ensuring the width of the working bands up to 7 ÷ 8% and 25 ÷ 28% of the average frequencies, respectively;

3) SWR at the antenna input of not more than 1.5 in both frequency ranges;

4) The gain in the low and high frequency ranges of 9-11 dB with respect to an isotropic emitter;

5) Antenna dimensions - (0.62 * λ _{cf. LF} ) * (0.62 * λ _{cf. LF} ) * (0.15 * λ _{cf. LF} ).

The technical result of the utility model is to simplify the design of the antenna while increasing the manufacturability of its implementation and reducing the size of the antenna.

To achieve the technical result, a dual-band antenna is proposed, consisting of an active vibrator located above the conductive screen, a balancing device, a coaxial input / output or RF transmission line, a conductive screen, holders, a protective casing, U-shaped shunts, supplemented with idling loops, the antenna is additionally equipped with two T-shaped shunts that are connected to the U-shaped shunts.

The dual-band antenna contains a symmetrical active vibrator located above the conductive screen, and which is fed through a balancing device from a coaxial input mounted on the screen. The balancing device, made in the form of a short-circuited bridge, consists of flat conductors, with some of the conductors forming a strip transmission line. Two short-circuited U-shaped shunts are connected to the vibrator’s shoulders, with each shunt supplemented by two idle loops installed in the sections between the middle of the shunt and the ends connected to the active vibrator. T-shaped shunts are additionally attached to the midpoints of the sections of the U-shaped shunts parallel to the OY axis. The active vibrator, shunts and idle loops lie in the same plane and form one piece made of sheet metal, fastened to the conductive screen with holders in the middle of the shunts and at points of zero potential. The balancing device and the conductive screen are also made of sheet metal. To protect the antenna from aggressive effects, a dielectric casing is fixed on the screen from the side of the radiating elements.

The inventive utility model is illustrated by the following illustrations:

Figure 1 is a General view of a dual-band antenna, where:

1 - protective dielectric casing of the antenna;

2, 3 - shoulders of the active vibrator;

4 - antenna screen;

5 - holders;

6 - U-shaped shunts;

7 - loops of idling;

8- T-shaped shunts;

9, 10, 11 - conductors of a balancing device;

12 - coaxial input / output of the antenna;

13 - connection points of U-shaped loops;

14 - connection points of idling loops.

Figure 2 is a General view of a dual-band antenna with dimensions, where:

15 - the length of the loop idling;

16 - the width of the idle loop and the portion of the U-shaped shunt parallel to the axis OY;

17 - the width of the plot of the U-shaped shunt parallel to the axis OX;

18, 27 - dimensions of the conductive screen;

19 - the dimension of the U-shaped shunt along the axis OY;

20 - the size of the gap between the shoulders of the active vibrator;

21 - the dimension of the U-shaped shunt along the axis OX;

22 - dimension of the active vibrator along the axis OX;

23 - the gap between the shoulder of the active vibrator and the T-shaped shunt;

24 - the width of the plot of the T-shaped shunt parallel to the axis OY;

25 - dimension of the active vibrator along the axis OY;

26 - the dimension of the T-shaped shunt along the axis OY;

28 - the distance between the screen and the active vibrator;

29 - the gap between the outer conductors of the balancing device.

The dual-band antenna consists of a split active vibrator (not shown in the figures), two U-shaped shunts 6 with idle loops 7 included in it, two T-shaped shunts 8 connected to the U-shaped shunts, holders 5, a balun device conductors 9, 10 and 11 with a gap between the outer conductors 29, the coaxial input 12, the conductive shield 4 and the protective dielectric casing 1. The dimensions of the antenna screen 18 and 27 are 0.58 * λ _{cf. LF} . The shoulders of the active vibrator are separated by a gap 20 equal to 0.018 * λ _{cf. HF} , and have contours close to rectangular, with cutouts in the region of the gap. The dimensions of the active vibrator 22 and 25 are 0.61 * λ _{cf. HF} and 0.67 * λ _{cf. HF,} respectively. In the plane of the active vibrator there are two U-shaped shunts 6, with inclusions in the form of idling loops 7 with a length of 15 equal to 0.11 * λ _{cf. LF} and a width of 16 equal to about 0.029 * λ _{cf. LF} . Shunts 6 are connected to the lateral sides of the shoulders of the active vibrator at points 13, while the dimensions of the U-shaped shunts 19 and 21 are 0.164 * λ _{cf. LF} and _0L * λ _{cf. LF,} respectively. The width of the 17 sections of the U-shaped shunts parallel to the OX axis is 0.014 * λ _{cf. LF} . Loops of idling 7 are included in the places of bending of shunts 6 - points 14. T-shaped shunts 8 connected to the middle of shunts 6 have sections parallel to the OY axis with dimensions 24 and 26 equal to 0.11 * λ _{cf. HF} and 0.29 * λ _cf. The gaps 23 between the T-shaped shunts 8 and the active vibrator are 0,047 * λ _cf. Active vibrator, U-shaped shunts 6, T-shaped shunts 8 and idling loops 7 are fixed above the conductive screen 4 at a distance of 28 equal to 0.1 * λ _{cf LF} , using holders 5, for the middle of the shunts 6. Balancing device installed between the active vibrator and the conductive screen 4, and connects the active vibrator and the connector 12. The antenna can be equipped with a protective dielectric casing 1, mounted on the screen 4 from the side of the emitters.

In order to improve the manufacturability of the antenna, a conductive screen, an active vibrator, idling loops, U-shaped shunts and T-shaped shunts and holders are made of sheet metal with the same processing method. Active vibrator, idling loops, U-shaped shunts, T-shaped shunts, conductors of a balancing device can be combined into one whole part.

The dual-band antenna operates in the low frequency range as follows:

When a signal is applied to arms 2 and 3, through a coaxial input / output 12 and a balancing device, the active vibrator is excited and, together with the conductive screen 4, generates linearly polarized radiation mainly in the positive direction of the OZ axis. U-shaped shunts 6, no-load loops 7 and a short-circuited bridge of a balancing device are reactive loads for an active vibrator and set the matching mode at the antenna input. The sections of the U-shaped shunts parallel to the OY axis, the open circuit 7 form linear vibrators that are excited through the sections of the shunts parallel to the OX axis, almost in phase with the active vibrator, which leads to an increase in the antenna gain. Holders 5 are attached to shunts 6 at voltage nodes and also do not affect the operation of the antenna. T-shaped shunts 8 have small electrical dimensions, are in a minimum field and have a small effect on the operation of the antenna in the low frequency range.

The dual-band antenna operates in the HF band as follows:

When a signal is applied to arms 2 and 3, through a coaxial input / output 12 and a balancing device, the active vibrator is excited and, together with the conductive screen 4, generates linearly polarized radiation mainly in the positive direction of the OZ axis. In this case, the shoulders of the active vibrator in this frequency range have increased electrical dimensions, and, consequently, an increased effective area, leading to an increase in gain. The sections of the U-shaped shunts parallel to the OY axis and the no-load loops 7 form linear vibrators that are excited through the sections of the shunts parallel to the OX axis, almost in phase with the arms of the active vibrator 2.3, which also leads to an increase in the antenna gain. There is a capacitive coupling between the free ends of the T-shaped shunts 8 and the sections of the U-shaped shunts 6 parallel to the OX axis, as well as the arms 2 and 3 of the active vibrator, through which alternating currents flow through the U-shaped shunts 6 and the arms of the vibrators 2 and 3, which affects the input impedance of the antenna in the high frequency range. One of the ends of the T-shaped shunts 8 is connected perpendicularly to the midpoints of the U-shaped shunts 6, at points of zero field potential, due to which the shunts 6 and 8 do not have additional direct electrical connections. The holders 5 are attached to the shunts 6 at the voltage nodes and do not affect the operation of the antenna in the high frequency range. The dimensions of the active vibrator, elements of the balancing device, U-shaped shunts, sections of T-shaped shunts parallel to the OY axis, idle loops, their relative position and location relative to the screen allows the antenna to be aligned with the transmission line.

The described design made it possible to obtain the following main characteristics when implementing the antenna for the frequency ranges 890-960 MHz (LF) and 1700-2200 MHz (HF):

1) SWR at the input of the antenna in variants matching with the coaxial line of 50 Ohms or 75 Ohms no more than 1.5 in both frequency ranges;

2) The gain in the low and high frequency ranges 9 ÷ 11 dB with respect to the isotropic emitter;

3) The dimensions of the antenna, taking into account the dimensions of the casing: 200 mm * 200 mm * 40 mm.

The aforementioned antenna gain in the low frequency range is achieved by: using an increased active vibrator and, as a result, having a large effective area, working shunts and idling loops as additional vibrators. A low reflection coefficient in the low frequency range is achieved by optimizing the size of the active vibrator and its position relative to the screen, the geometry of the shunts, idling loops and a balancing device.

The above antenna gain in the HF frequency range is achieved through the use of an increased active vibrator and, as a result, having a large effective area, as well as through the use of U-shaped shunts and idling loops as additional vibrators. A low reflection coefficient in the HF range is achieved by optimizing the size of the vibrators, installing T-shaped shunts and their location relative to the active vibrator, features of the geometry of the shunts, idling loops and a balancing device.

The reduction in the size of the antenna is also achieved due to the presence of T-shaped shunts that perform the function of additional vibrators, thus, there is no need to use at least four passive vibrators described in the prototype (patent No. RU 148192 of 03.24.2014, option 2), thanks to which the dimensions of the antenna are reduced.

Claims (3)

1. A dual-band antenna consisting of a balancing device, a coaxial input / output, a conductive screen, an active vibrator that is fed through a balancing device from a coaxial input / output and is located above the conductive screen, holders, a protective casing, U-shaped shunts connected to the shoulders active vibrator and supplemented with idle loops, characterized in that the antenna is additionally equipped with two T-shaped shunts that are connected to the U-shaped shunts. 2. The dual-band antenna according to claim 1, characterized in that the active vibrator, U-shaped, T-shaped shunts, idle loops lie in the same plane and form a separate whole part. 3. The dual-band antenna according to claim 1, characterized in that the active vibrator, U-shaped and T-shaped shunts, idle loops, a conductive screen, conductors of a balancing device, holders are made of sheet metal with the same processing method.

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