CN212848801U - Short-wave double-layer array log-periodic broadband antenna - Google Patents
Short-wave double-layer array log-periodic broadband antenna Download PDFInfo
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- CN212848801U CN212848801U CN202022188639.0U CN202022188639U CN212848801U CN 212848801 U CN212848801 U CN 212848801U CN 202022188639 U CN202022188639 U CN 202022188639U CN 212848801 U CN212848801 U CN 212848801U
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Abstract
The utility model relates to a high frequency antenna technical field discloses a short wave double-layer array log-periodic broadband antenna, including irradiator, feed network, antenna tower, lower lead wire pole and acting as go-between, the irradiator is bilayer structure, and every layer irradiator contains oscillator and set line, and the multiunit oscillator is parallel to each other between the multiunit oscillator to the position of the length of multiunit oscillator on the set line distributes according to log-periodic antenna's rule; the antenna tower comprises two high antenna towers and two low antenna towers and is used for fixing two ends of each layer of radiating body; the feed network is connected with the radiator and the radio frequency cable to realize impedance matching; the lower lead rod is arranged at the end of the low antenna tower and used for supporting the feed network and fixing the radio frequency cable; one end of the stay wire is connected with the top end of the antenna tower, the other end of the stay wire is fixed on the ground, and the plurality of stay wires are used for fixing the antenna tower. The utility model discloses an antenna has gain height, radiation angle of elevation low, the directionality is strong, bear power big, occupation of land size advantage such as less relatively.
Description
Technical Field
The utility model relates to an antenna technology field, especially a shortwave double-deck array log-periodic broadband antenna.
Background
Short wave communication is a communication mode for achieving information transfer by utilizing ionosphere reflection, and is an effective means for realizing global coverage and long-distance mobile communication. The antenna is used as a front-end component of a short-wave communication system and plays a crucial role in communication quality.
A 527 series, 527B series dual layer log periodic antenna developed by TCI corporation of america is shown in figure 1. The 527-3-04 type antenna has the working frequency of 6.2 MHz-30 MHz, the bearing power of 25kW (average) and 50kW (peak value), the gain of about 17.5dBi, the beam width of 38 degrees, the maximum gain elevation angle range of 12-20 degrees, the antenna height of 51.8 meters and the occupied space size of 118.3 meters multiplied by 166 meters. The 527B-8-04 type antenna has the working frequency of 6.2 MHz-30 MHz, the bearing power of 25kW (average), 50kW (peak value), the gain of 15.2dBi, the beam width of 64 degrees, the maximum gain elevation angle range of 13-20 degrees, the antenna height of 46 meters and the occupied ground size of 101 meters multiplied by 125 meters. The two types of antennas have large occupied area, and in practical application, a proper antenna erection site is difficult to find.
Relatively speaking, domestic short wave antennas are mainly introduced from abroad, and mainly comprise double-layer diamond antennas and double-layer horizontal log periodic antennas. The working frequency of the double-layer diamond antenna is 3 MHz-30 MHz, the bearing power is 10kW, the gain is 20dBi, the beam width is 30 degrees, the maximum gain elevation angle range is 8-30 degrees, the antenna height is 40 meters, and the occupied space is 80 meters multiplied by 120 meters. The working frequency of the double-layer horizontal log periodic antenna is 6.2 MHz-30 MHz, the bearing power is 30kW, the gain is 16dBi, the beam width is 60 degrees, the maximum gain elevation range is 10-25 degrees, the antenna height is 40 meters, and the floor area is 100 meters multiplied by 120 meters. The domestic double-layer horizontal log periodic antenna also has the problem of large floor area.
Generally, domestic double-layer diamond antennas or double-layer horizontal log-periodic antennas have some problems based on the same electrical performance indexes: firstly, the remote communication capability is not enough, and the communication distance is limited; secondly, the planning of an antenna feeder system is not scientific, the antenna of the conventional station has single type, and the overall planning of distance matching and near matching is lacked, so that the communication guarantee requirements under various coverage conditions cannot be met; thirdly, the reliability and the environmental adaptability of the antenna feeder system are poor. In addition, the problems of overlarge occupied area, relatively high cost, poor autonomous controllable degree and the like exist.
SUMMERY OF THE UTILITY MODEL
The invention of the utility model aims to: aiming at the defects of overlarge occupied area, relatively high cost, poor autonomous controllable degree and the like, the conventional double-layer log periodic antenna is improved, and the short-wave double-layer array log periodic broadband antenna is provided.
In order to realize the purpose, the utility model discloses a technical scheme be:
a short-wave double-layer array log-periodic broadband antenna comprises a radiator, a feed network, an antenna tower, a lower lead rod and a stay wire,
the radiator is of a double-layer structure, each layer of radiator comprises vibrators and an assembly line, a plurality of groups of vibrators are parallel to each other, and the lengths of the vibrators and the positions of the vibrators on the assembly line are distributed according to the rule of a log-periodic antenna;
the antenna tower comprises two high antenna towers and two low antenna towers and is used for fixing two ends of each layer of radiating body;
the feed network is connected with the radiator and the radio frequency cable to realize impedance matching;
the lower lead rod is arranged at the end of the low antenna tower and used for supporting the feed network and fixing the radio frequency cable;
one end of the stay wire is connected with the top end of the antenna tower, the other end of the stay wire is fixed on the ground, and the plurality of stay wires are used for fixing the antenna tower.
As the utility model discloses a preferred scheme, every layer of irradiator contains 18 groups oscillators, and the oscillator adopts the line footpath to be 6mm copper wire rod.
As a preferred embodiment of the present invention, the width of one end of the radiator is 20.06 meters, and the width of the other end of the radiator is 24 meters.
As the preferred scheme of the utility model, area is less than or equal to 4400 square meters.
As the preferred scheme of the utility model, high antenna tower height 36 meters, low antenna tower height 15 meters, down lead wire pole height 9 meters.
As the preferred scheme of the utility model, the feed network includes transformer T1, electric capacity C1, inductance L1, inductance L2 and matching resistance, wherein, electric capacity C1 and inductance L1 connect in parallel in a and B two points, inductance L2 one end is connected with A point, the other end of inductance L2 is connected with the irradiator, B point ground connection;
the transformer T1 has three taps, the middle tap is connected to point A, and the two taps are connected in parallel with the matching resistor.
As the preferred scheme of the utility model, the transformer T1 adopts 60 slice haplopore nickel zinc.
As the preferred scheme of the utility model, the size of the flake single-hole nickel zinc is phi 360 multiplied by phi 120 multiplied by 5 mm.
As the preferred scheme of the utility model, the working frequency range is 7MHz ~ 30 MHz.
As a preferable proposal of the utility model, the voltage standing wave ratio between the frequency bands of 7MHz and 30MHz is less than or equal to 2.0.
To sum up, owing to adopted above-mentioned technical scheme, the beneficial effects of the utility model are that:
1. the utility model discloses a double-deck array log cycle broadband antenna of shortwave mainly is applied to the end of posting a letter, converts the high frequency current (radio frequency signal) of transmitter into and transmits to the distant place to the electromagnetic wave of space radiation to can launch high-power radio frequency signal, but adaptation 25kW short wave transmitter. The antenna adopts directional radiation, the horizontal plane beam width can reach more than 60 degrees, and the effective coverage distance in the communication direction can reach more than 10000 kilometers.
2. The utility model discloses a short wave double-deck array log-periodic broadband antenna has gain height, radiation angle of elevation low, the directionality is strong, bear advantage such as power is big, the occupation of land size is less relatively, can satisfy the communication guarantee demand under the multiple cover condition.
Drawings
FIG. 1 is a schematic diagram of a 527, 527B series antenna developed by TCI corporation in the United states of America in the prior art of the present invention;
fig. 2 is a structure diagram of a short-wave double-layer array log periodic broadband antenna in embodiment 1 of the present invention;
fig. 3 is a diagram of the connection relationship between the short-wave double-layer array log-periodic broadband antenna and the radio equipment in embodiment 1 of the present invention;
fig. 4 is a basic structure diagram of a log periodic antenna radiator in embodiment 1 of the present invention;
fig. 5 is a top view of the antenna radiator according to embodiment 1 of the present invention;
fig. 6 is a side view of the size of the radiator in embodiment 1 of the present invention;
fig. 7 shows a flow chart of embodiment 1 of the present invention: 6, the overall structure of the transmission line transformer feedback network;
fig. 8 is a diagram of the actual footprint of the antenna in embodiment 1 of the present invention.
Reference numerals: the tower body is 36 meters, the tower body is 15 meters, the antenna radiator is arranged, the gathering line is arranged, and the auxiliary line is arranged.
Detailed Description
The present invention will be described in detail with reference to the accompanying drawings.
In order to make the objects, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the invention.
Example 1
A structure diagram of a short-wave double-layer array log-periodic broadband antenna is shown in fig. 2, and comprises a radiator, a feed network, an antenna tower, a lower lead rod and a stay wire.
The radiator mainly performs an energy conversion function, that is, a high-frequency current (radio frequency signal) from the transmitter is converted into a corresponding electromagnetic wave, and the electromagnetic wave is radiated to the surrounding space. In this embodiment, the radiator is a radiator of two pairs of log periodic antennas, the radiators of the two pairs of log periodic antennas form a binary array at a certain angle in a vertical plane, and the length and the distance of the elements in the radiators are designed according to the log periodic antennas.
The log periodic antenna is constructed according to the theory set forth below: the antenna remains in its original configuration after being transformed by a particular scaling factor tau. Thus, the antenna performance, which occurs at frequencies τ f and τ, will be at τ f and τ2f, and so on, the electrical performance of the antenna will vary periodically over a wide frequency range. Therefore, if the performance index change of the antenna in the f-tauf frequency band is small, the requirement of the non-frequency-varying antenna can be met. Meanwhile, the log periodic antenna is a linearly polarized antenna, and the polarization direction of an electric field is parallel to the direction of the oscillator. Therefore, the log periodic antenna has broadband characteristics and linear polarization characteristics, so that the application of the log periodic antenna as a corona discharge signal detection system is the optimal choice for an antenna part.
The log periodic antenna is composed of N symmetrical oscillators arranged in parallel according to a structural period rate, and has the following relation
In the formula: dn、ln、RnRespectively the distance between two adjacent oscillators,The distance between the virtual vertex and the oscillator and the vertical distance between the geometric vertex of the antenna and the nth oscillator; the serial number of the vibrator is n.
As shown in fig. 3, the overall structure of the log periodic dipole antenna is determined by the period rate and the structural opening angle 2 α. When the periodicity and 2 α are determined, the geometry of the log periodic antenna is also determined. Due to Rn+1＝τRnAnd Rn＝(In/2) cot α, therefore
Thus, in determining the design parameters of the antenna. As long as τ and 2 α are known, the geometry and electrical characteristics of the antenna are determined. Antenna length L ═ InAnd/2) cot α, the antenna length is greatly reduced as the opening angle α is increased.
To ensure that the antenna meets the requirements at both ends of the frequency band, the high and low end dipole lengths are typically designed using the high and low end cutoff constants of the frequency band, and the number of dipoles required is determined accordingly. The longest dipole length is L1＝K1λL，λLIs the longest operating wavelength, K1Is the low end cut-off constant, K2Is the high-end cutoff constant. The shortest dipole length of a log periodic antenna is LU＝K2λUIn this formula, λUIs the shortest operating wavelength. The number of dipoles on the antenna can be obtained by using the two cut-off constants and the highest and lowest frequencies of the frequency band.
The method for determining the length and the distance of the oscillators is the prior art, and is detailed in terms of hundred-degree encyclopedic log-periodic antenna entries.
The feed network is mainly used for impedance matching between the antenna and the feed line and is made of passive devices, so that loss caused by impedance mismatch is reduced, the bearing power and the feed efficiency are improved, and the broadband of the input impedance of the antenna is realized.
The antenna tower and down-lead mast are primarily used to support the radiator and feed network so that the antenna has the required electrical performance and can operate safely. In the embodiment, four groups of guyed towers and a group of lower lead rods are adopted, and the tower body adopts a lifting mode, so that the tower has the characteristics of convenience in installation, stable structure and the like.
The short wave transmitting system consists of mainly transmitter, feeder, antenna and other equipment, and the transmitter has the main function of modulating the high frequency signal into RF carrier signal and outputting the RF carrier signal. The short-wave double-layer array log-periodic broadband antenna in the embodiment is used as a back-end device of a short-wave transmitting system, and can be directly connected with a transmitter through a feeder line and also can be connected to other devices in the system, and the connection relationship between the antenna and the radio station device is shown in fig. 4.
1) Design of antenna radiator
The radiation characteristic of the antenna array depends on the type, number, arrangement mode, array element spacing and current amplitude and phase distribution on the array elements, and the radiation field is vector superposition of electromagnetic fields generated by the antenna elements, so that the directivity of the antenna is enhanced, and the gain coefficient is improved.
The basic structure of the log periodic antenna radiator consists of a gathering line and a half-wave oscillator. The assembly line is usually a double-pipe line or other double-line, and oscillators with certain sizes distributed regularly are arranged on two sides of the assembly line in a staggered mode. The length of the longest vibrator and the shortest vibrator is determined by the upper limit and the lower limit of the working frequency band, and the distance and the length of each vibrator are subject to the proportionality coefficient. The structure of the log periodic antenna is a structure loading a log periodic dipole antenna array on parallel straight wires, and a basic schematic diagram of the structure is shown in fig. 5, the antenna in the form is characterized in that double transmission lines are used as feeder lines, the feeder lines are also called as aggregate lines, N pairs of symmetrical oscillators arranged in parallel are attached to the aggregate lines, and transmission power is transmitted to corresponding radiation areas along the aggregate lines and is radiated outwards from the symmetrical oscillators. The sizes of the dipoles and the positions on the set line are distributed according to the rule of the log-periodic antenna.
Through calculation simulation and analysis, the finally designed short-wave double-layer array log-periodic broadband antenna is shown in fig. 2, the radiator adopts a double-layer structure, the radiator comprises an upper-layer antenna radiator and a lower-layer antenna radiator, the antenna radiator is called an antenna body in the figure, correspondingly, the upper-layer antenna radiator is an upper-layer antenna body, and the lower-layer antenna radiator is a lower-layer antenna body. Each layer of radiator is formed by arranging 18 groups of vibrators in a proportional relation, the 18 groups of vibrators are mutually parallel, the assembly line is designed in a double-line mode, and the joints of the radiators are reliably connected in a crimping mode, so that good conductivity is guaranteed. The radiator is made of copper wire with good conductivity and high tensile strength, and the wire diameter is 6mm (guaranteed to bear 25kW of power). As shown in fig. 5, the width of one end of the radiator is 20.06 meters, and the width of the other end of the radiator is 24 meters. The radiator is shown in side view in figure 6.
2) Design of feed network
The bandwidth requirement of the short-wave double-layer array log-periodic broadband antenna is 7 MHz-30 MHz, the designed radiator result shows that the real part of the input impedance of the antenna radiator is far away from the 50 omega characteristic impedance of the radio-frequency cable, if the antenna radiator is directly connected with the radio-frequency cable, the impedance mismatch loss in a working frequency band reaches more than 60%, and the signal power transmitted by the radio-frequency cable cannot be effectively transmitted to the antenna radiator, so that the optimized frequency range is set to be 7 MHz-30 MHz, the frequency sampling point is set to be 460 points, and the comprehensive analysis is carried out to determine that the antenna adopts 1: 6 transmission line transformer feedback network, transformation ratio 1 of transformer in T1: n, N is equal to 6, 1: the overall structure of the 6-line transformer backfeed network is shown in fig. 7, where T1 is 1: 6 transmission line transformers. The feed network comprises a transformer T1, a capacitor C1, an inductor L1, an inductor L2 and a matching resistor R, wherein the capacitor C1 and the inductor L1 are connected in parallel at a point A and a point B, one end of the inductor L2 is connected with the point A, the other end of the inductor L2 is connected with the radiator, and the point B is grounded; the two ends of the first winding of the transformer T1 are connected in parallel with the matching resistor R, and the two ends of the second winding of the transformer T1 are connected in parallel with the capacitor C1 at the two points A and B.
As a preferred scheme, the ideal transformer magnetic core is made of a sheet single-hole nickel-zinc (NiZn) ferrite material, the size of a single sheet is phi 360 multiplied by phi 120 multiplied by 5mm (outer diameter multiplied by inner diameter multiplied by thickness), the single sheet can bear 500W, and in combination with a redundancy design, 60 sheets are selected for combination, so that the saturated bearing capacity is 30kW, and the power bearing requirement of 25kW is met.
Preferably, the transmission line is selected in consideration of the loss of the cable, the wire diameter, the load power for manufacturing the feed network and other factors. At present, the types of transmission lines for winding the magnetic ring are more, and the transmission lines comprise high-temperature wires, coaxial cables, enameled wires and the like. Calculated, 25mm is used in this embodiment2The silver-plated high-temperature wire is used as a transmission line to wind the magnetic ring, and the connection of the transmission line is processed in a compression joint mode.
Preferably, the radio frequency interface adopts an L52 radio frequency connector, and meets the 25kW power bearing requirement.
As the preferred scheme, the external cavity of the feed network is designed to adopt a novel physical heat dissipation cavity on the premise of not increasing cost and weight so as to realize the problem of heat dissipation of the magnetic core, 600 multiplied by 500 multiplied by 400mm aluminum profiles are selected as the cavity, fins with tooth intervals are arranged outside, the heat dissipation efficiency can be improved by 45-48%, the heat dissipation capacity can reach 200 ℃, and the temperature bearing requirement of the cavity of the feed network is met.
3) Antenna tower, lower lead rod and guy wire design
The utility model discloses in, the antenna tower that supports the antenna radiator chooses for use over-and-under type guyed tower structure, as shown in fig. 3, has four antenna towers altogether, two high antenna towers (also called high-end tower), two low antenna towers (also called low-end tower), and the down lead rod supports and adopts guyed rod body structure.
Simulation verification proves that the maximum gain elevation angle range of the antenna of the embodiment in the frequency band of 7MHz to 30MHz is about 6 degrees to 30 degrees. After actual erection, the height of the four antenna towers is 36 meters, the height of the four antenna towers is 15 meters, and the down lead rods are 9 meters. The actual footprint of the antenna is approximately a trapezoid, and the actual footprint of the antenna is as shown in fig. 8, with a longer base of 54.74 meters, a shorter base of approximately 35 meters, and a total span of 79.62 meters, i.e., the footprint of the antenna is 54.74 meters × 79.62 meters (including the guy wires), which is 4358.3988 square meters. The antenna has a communication distance of about 6000 km at a frequency around 10MHz, a communication distance of about 7000 km at a frequency around 15MHz, and a communication distance of about 8500 km at a frequency around 20 MHz. The voltage standing wave ratios in the frequency bands of 7MHz to 30MHz are all less than or equal to 2.0.
The above description is only exemplary of the present invention and should not be taken as limiting the scope of the present invention, as any modifications, equivalents, improvements and the like made within the spirit and principles of the present invention are intended to be included within the scope of the present invention.
Claims (10)
1. A short-wave double-layer array log-periodic broadband antenna is characterized by comprising a radiator, a feed network, an antenna tower, a lower lead rod and a stay wire,
the radiating bodies are of a double-layer structure, each layer of radiating bodies comprises vibrators and an aggregation line, a plurality of groups of vibrators are parallel to each other, and the lengths of the vibrators and the positions of the vibrators on the aggregation line are distributed according to the rule of a log-periodic antenna;
the antenna tower comprises two high antenna towers and two low antenna towers and is used for fixing two ends of each layer of radiating body;
the feed network is connected with the radiator and the radio frequency cable to realize impedance matching;
the lower lead rod is arranged at the end of the low antenna tower and used for supporting the feed network and fixing the radio frequency cable;
one end of each stay wire is connected with the antenna tower, the other end of each stay wire is fixed to the ground, and the plurality of stay wires are used for fixing the antenna tower.
2. A short wave double layer array log periodic broadband antenna as claimed in claim 1 wherein each layer radiator comprises 18 groups of elements.
3. A short wave double layer array log periodic broadband antenna as claimed in claim 2 wherein the width of one end of the radiator is 20.06 meters and the width of the other end of the radiator is 24 meters.
4. The short-wave double-layer array log-periodic broadband antenna of claim 3, wherein a footprint is less than or equal to 4400 square meters.
5. The short-wave double-layer array log-periodic broadband antenna of claim 4, wherein the high antenna tower is 36 meters high, the low antenna tower is 15 meters high, and the down-lead mast is 9 meters high.
6. A short-wave double-layer array log-periodic broadband antenna as claimed in any one of claims 1-5, wherein the feed network comprises a transformer T1, a capacitor C1, an inductor L1, an inductor L2 and a matching resistor R, wherein the capacitor C1 and the inductor L1 are connected in parallel at the point A and the point B, one end of the inductor L2 is connected with the point A, the other end of the inductor L2 is connected with the radiator, and the point B is grounded;
the two ends of the first winding of the transformer T1 are connected in parallel with the matching resistor R, and the two ends of the second winding of the transformer T1 are connected in parallel with the capacitor C1 at two points A and B.
7. The short-wave double-layer array log-periodic broadband antenna of claim 6, wherein the transformer T1 is 60 sheet-shaped single-hole nickel zinc.
8. The short-wave double-layer array log-periodic broadband antenna of claim 7, wherein the sheet-like single-hole nickel-zinc size is 360 x 120 x 5 mm.
9. The short-wave double-layer array log-periodic broadband antenna of claim 8, wherein the operating frequency range is 7MHz to 30 MHz.
10. The short-wave double-layer array log-periodic broadband antenna of claim 9, wherein the voltage standing wave ratio in the 7 MHz-30 MHz band is less than or equal to 2.0.
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| CN202022188639.0U CN212848801U (en) | 2020-09-29 | 2020-09-29 | Short-wave double-layer array log-periodic broadband antenna |
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| CN202022188639.0U CN212848801U (en) | 2020-09-29 | 2020-09-29 | Short-wave double-layer array log-periodic broadband antenna |
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