CN210692752U

CN210692752U - Miniaturized dual-frequency circuit loading helical antenna

Info

Publication number: CN210692752U
Application number: CN201921776887.8U
Authority: CN
Inventors: 李俊; 姚凤薇; 周春龙; 刘平
Original assignee: Shanghai Dandi Communication Tech Co ltd
Current assignee: Shanghai Dandi Communication Tech Co ltd
Priority date: 2019-10-22
Filing date: 2019-10-22
Publication date: 2020-06-05
Anticipated expiration: 2029-10-22

Abstract

The utility model relates to the technical field of antennas, especially, relate to a miniaturized dual-frenquency circuit loading helical antenna, through set up an insulating cylinder on the feed base plate that has phase shift feed network, and there are 4 dual-frenquency radiation arms along helical antenna's direction of height spiral winding towards one direction on this insulating cylinder, and set up that every dual-frenquency radiation arm all includes a tortuous helix and a straight helix, the end-to-end connection of this tortuous helix and straight helix is in the same place and respectively the one-to-one connects on 4 of phase shift feed network present the point, thereby make this dual-frenquency circuit loading helical antenna can have miniaturization and dual-frenquency characteristic concurrently, the overall arrangement is ingenious, can realize the better standing wave and radiation characteristic of two frequency channels in less limit space, have very strong practicality and application prospect.

Description

Miniaturized dual-frequency circuit loading helical antenna

Technical Field

The utility model relates to the technical field of antennas, especially, relate to a miniaturized dual-frenquency circuit loading helical antenna.

Background

In recent years, satellite mobile communication has been widely used, and a plurality of ground terminal application systems, especially handheld systems, for different services have been developed, due to the uncertainty of the service type and the user posture, the antenna is required to have the performance of sharing a wide beam with multiple frequency bands, high efficiency, and the like! As an electromagnetic wave receiving and transmitting device of a satellite ground handheld terminal device, an antenna plays a very important role, the performance of the antenna directly determines the positioning precision and speed of a terminal user, the cost, the volume and the mass of the antenna determine the size and the price of the device, and the market prospect of products is indirectly influenced.

Compared with other satellite communication antennas, the quadrifilar helix antenna in the axial mode has the advantages of high efficiency, good circular polarization performance, capability of forming a hemispherical radiation pattern and the like, so that the quadrifilar helix antenna becomes a satellite communication antenna form which is concerned with, but the existing quadrifilar helix antenna has a larger size or a higher height, and cannot meet the miniaturization requirement of a handheld terminal antenna. Furthermore, the dual-band helical antenna in the literature currently available is generally closer in frequency to the two, with the ratio of high and low frequencies not exceeding 1.5:1, which is undesirable to those skilled in the art.

SUMMERY OF THE UTILITY MODEL

To the problem that above-mentioned exists, the utility model discloses a miniaturized dual-frenquency circuit loading helical antenna, wherein, include: the circuit loading structure comprises a circuit loading structure, an insulating cylinder and 4 double-frequency radiating arms;

the circuit loading structure comprises a feed substrate and a phase-shift feed network arranged on the upper surface of the feed substrate, wherein 4 feed points are arranged on the phase-shift feed network;

the feed base plate set up in insulating cylinder's inside is located insulating cylinder's bottom, 4 dual-frenquency radiation arm all follows helical antenna's direction of height orientation helical winding is in on insulating cylinder's the outer wall, and every dual-frenquency radiation arm all includes a tortuous helix and a straight helix, tortuous helix with the end-to-end connection of straight helix is in the same place, 4 dual-frenquency radiation arm tortuous helix with interval between the straight helix is all the same, and 4 dual-frenquency radiation arm's end difference one-to-one is connected on 4 feeds of phase shift network are put.

The miniaturized dual-frequency circuit loading helical antenna is characterized in that the rising angles of the zigzag helical line and the straight helical line are both 20-75 degrees.

The miniaturized dual-frequency circuit loading helical antenna is characterized in that the width of the zigzag helical line and the width of the straight helical line both have a value range of 0.5-1.5 mm.

The miniaturized double-frequency circuit loading spiral antenna is characterized in that the feed substrate is of a double-sided structure, 4 bonding pads and a feed point are arranged on the lower surface of the feed substrate, the number of the bonding pads is 4, the bonding pads are respectively communicated with the number of the feed points through metallized through holes, the number of the feed points is 4, the tail ends of the double-frequency radiating arms are respectively welded on the 4 bonding pads in a one-to-one correspondence mode, and the feed points are used for being connected with cables.

The miniaturized dual-band circuit loading helical antenna is characterized in that the feed substrate is circular, and the phase-shift feed network comprises an LTCC balun, 2 3dB bridges and 4 feed points.

The 4 feed points are uniformly distributed on the edge of the feed substrate and are positioned on the same circumference, unbalanced ports of the LTCC balun are connected with the feed points through metalized through holes, a first balanced port of the LTCC balun is connected with 2 adjacent feed points in the 4 feed points through one 3dB bridge, a second balanced port of the LTCC balun is connected with the remaining 2 adjacent feed points in the 4 feed points through the other 3dB bridge so as to convert electric signals input by the cable into feed signals with equal amplitude, and the phases are sequentially different by 90 degrees and output.

The miniaturized dual-frequency circuit loading helical antenna comprises a first inductor, a second inductor, a first capacitor, a second capacitor, a grounding inductor and a grounding capacitor, wherein the LTCC balun comprises a first inductor, a second inductor, a first capacitor, a second capacitor, a grounding inductor and a grounding capacitor;

the first inductor and the second inductor are connected in series between the unbalanced port and the first balanced port, and the grounding capacitor is connected between the first inductor and the second inductor;

the first capacitor and the second capacitor are connected in series between the unbalanced port and the second balanced port, and the grounding inductor is connected between the first capacitor and the second capacitor.

In the miniaturized dual-frequency circuit loading helical antenna, the dual-frequency radiating arm is printed on the flexible material layer, and the flexible material layer is attached to the insulating cylinder.

The miniaturized dual-frequency circuit loading helical antenna is characterized in that the dielectric constant of the flexible material layer is 2-5.

The miniaturized dual-frequency circuit loading helical antenna is characterized in that the thickness of the flexible material layer is less than 0.5 mm.

The miniaturized dual-frequency circuit loading helical antenna is characterized in that the thickness of the feeding substrate is 0.5-2 mm.

Above-mentioned utility model has following advantage or beneficial effect:

the utility model discloses a miniaturized dual-frequency circuit loading helical antenna, which is characterized in that an insulating cylinder body is arranged on a feed substrate with a phase shift feed network, 4 dual-frequency radiation arms are spirally wound on the insulating cylinder body along the height direction of the helical antenna towards one direction, each dual-frequency radiation arm comprises a zigzag helix and a straight helix, and the tail ends of the zigzag helix and the straight helix are connected together and respectively connected to 4 feed points of the phase shift feed network in a one-to-one correspondence manner; because this helical antenna adopts straight helix and tortuous helix can realize the dual-frenquency radiation, and the dual-frenquency frequency ratio is greater than 1.5, and adopt including the balun, the feed network of elements such as two 3dB electrical bridges, thereby make this dual-frenquency circuit loading helical antenna have miniaturization and dual-frenquency characteristic concurrently, it is ingenious to arrange overall arrangement, can realize the better standing wave and radiation characteristic of two frequency channels in less limit space, have very strong practicality and application prospect, and this loading helical antenna is as a handheld satellite communication antenna, have the heart shape directional diagram, good front-to-back ratio and excellent wide wave beam circular polarization characteristic, very be fit for being used as satellite positioning system's receiving antenna.

Drawings

The invention and its features, aspects and advantages will become more apparent from a reading of the following detailed description of non-limiting embodiments with reference to the attached drawings. Like reference symbols in the various drawings indicate like elements. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention.

Fig. 1 is a schematic structural diagram of a miniaturized dual-band circuit loading helical antenna in an embodiment of the present invention;

fig. 2 is a top view of a circuit loading structure in an embodiment of the present invention;

fig. 3 is a schematic structural diagram of balun in the embodiment of the present invention;

fig. 4 is a bottom view of the circuit loading structure in the embodiment of the present invention.

Detailed Description

Balun (Balun) is a three-port device consisting of one unbalanced port and two balanced ports. The signals of the two balanced ports have a phase shift of 180 ° and the same amplitude. The 3dB bridge, also called a co-frequency combiner, can continuously sample transmission power along a certain direction of a transmission line, and can divide an input signal into two signals which are equal in amplitude and have a phase difference of 90 degrees. The method is mainly used for multi-signal combination, improves the utilization rate of output signals, is widely applied to combination of base station signals in an indoor coverage system, and has good application effect in the places.

The balun forms a network with 180-degree phase difference between the left and right circuits, and the left and right sides of the network are respectively connected with the 3dB electric bridge, so that four ports of the output port with 90-degree phase difference in sequence are formed, and the phase requirement of the four-arm helical antenna is met.

The present invention will be further described with reference to the accompanying drawings and specific examples, which should not be construed as limiting the invention.

As shown in fig. 1 to 4, the present embodiment relates to a miniaturized dual-band circuit-loaded helical antenna, which adopts a bottom feeding manner, and specifically, the helical antenna includes: the circuit loading structure comprises a circuit loading structure 1, an insulating cylinder 3 and 4 double-frequency radiating arms 2; the circuit loading structure 1 comprises a feed substrate 15 and a phase shift feed network arranged on the upper surface of the feed substrate, wherein 4

feed points

11, 12, 13 and 14 are arranged on the phase shift feed network; the feed substrate 15 is arranged inside the insulating cylinder 3 and located at the bottom of the insulating cylinder 3, and the 4 dual-frequency radiating arms 2 are spirally wound on the outer wall of the insulating cylinder 3 towards one direction (left-handed or right-handed, and the rotating directions of the 4 dual-frequency radiating arms 2 are consistent) along the height direction of the spiral antenna, wherein the dual-frequency radiating arms 2 are printed on a flexible material layer (not shown in the figure), and the flexible material layer is attached to the insulating cylinder 3; each dual-frequency radiating arm 2 comprises a zigzag helix 21 and a straight helix 22 (because the frequency difference of the two helices is large, the frequency ratio is larger than 1.5, so that one helix is set to be a straight line, and the other helix is a zigzag line, so that firstly, the overall height of the insulating cylinder 3 can be shortened, secondly, the crossing of the two helices caused by different helix angles can be avoided, wherein the straight helix 22 radiates higher frequency, the zigzag helix 21 radiates lower frequency band), the tail ends of the zigzag helix 21 and the straight helix 22 are connected together to form a feed point, the distances between the zigzag helix 21 and the straight helix 22 of the 4 dual-frequency radiating arms 2 are the same (the distance between the zigzag helix 21 and the straight helix 22 in a single dual-frequency radiating arm 2 is set to be a first distance, and the first distances of the 4 dual-frequency radiating arms 2 are the same), and the tail ends of the 4 double-frequency radiation arms 2 are respectively connected to 4 feed points of the phase shift feed network in a one-to-one correspondence manner.

In the embodiment of the present invention, the value range of the width of the zigzag helix 21 and the straight helix 22 is 0.5-1.5 mm (e.g. 0.5mm, 1mm, 1.2mm or 1.5 mm). The rising angle of the zigzag spiral line 21 and the straight spiral line 22 is 20-75 degrees, so that the dual-frequency radiation arm can form a dual-frequency radiation spiral line with the high-low frequency ratio larger than 1.5. Because the frequency ratio of the two frequencies is more than 1.5, if the two arms are all linear spiral arms, the two arms are crossed, one is a zigzag line, the other is a straight line, and the antenna resonates at a required working point by adjusting the lift angle, the length and the thickness of the two lines.

In a preferred embodiment of the present invention, the dielectric constant (relative dielectric constant) of the flexible material layer is between 2 and 5, and the thickness of the flexible material layer is less than 0.5 mm.

In a preferred embodiment of the present invention, the tangent tg δ of the loss angle δ of the medium of the feed substrate is not more than 10^-3And the thickness of the feeding substrate is 0.5-2mm (e.g. 0.5mm, 1mm, 1.7mm or 2 mm).

In a specific embodiment of the present invention, the feeding substrate is printed on both sides, the upper surface is printed with a phase shift feeding network, the lower surface is provided with 4

metal pads

16, 17, 18, 19 and a feeding point 20, and the feeding point 20 is used for connecting with a cable. The feeding substrate is a circular PCB, the phase shift feeding network includes an LTCC balun, 2 3dB bridges and 4

feeding points

11, 12, 13, and 14, the 4

feeding points

11, 12, 13, and 14 are uniformly distributed at the edge of the circular PCB 15 and located on the same circumference (i.e. the 4

feeding points

11, 12, 13, and 14 are located at the edge of the circular PCB, and are symmetrically cross-disposed, if the feeding substrate is divided into four quadrants, each quadrant includes one feeding point), the 4

metal pads

16, 17, 18, and 19 are respectively connected to the 4

feeding points

11, 12, 13, and 14 through metal holes, and the 4

metal pads

16, 17, 18, and 19 are respectively welded to the 4 dual-frequency radiation arms 22 (it can also be said that the tail ends of the 4 dual-frequency radiation arms 2 are respectively welded to the 4 metal pads one by one), so that the 4 dual-frequency radiation arms 22 respectively correspond to the 11, 4 feeding points one by one, and the tail ends of the 4 dual-frequency radiation arms 22 are respectively connected to the metal pads, 12. 13, 14 connection; the unbalanced port of the balun is connected with a cable through a feeding point (the upper surface of the feeding substrate is provided with a connecting point connected with the unbalanced port of the balun, and the connecting point is communicated with the feeding point through a metal hole), the first balanced port of the balun is connected with 2

adjacent feeding points

11 and 12 in 4 feeding points through a 3dB bridge, and the second balanced port of the balun is connected with the remaining 2

adjacent feeding points

13 and 14 in the 4 feeding points through another 3dB bridge so as to convert electric signals input by the cable into feeding signals with equal amplitude, the phases of the feeding signals are sequentially different by 90 degrees, and the power is divided equally; the phases of the 4 feed points are 0 degrees, 90 degrees, 180 degrees and 270 degrees respectively; wherein the phase of the feed point 11 is 270 °, the phase of the feed point 12 is 180 °, the phase of the feed point 13 is 90 °, and the phase of the feed point 14 is 0 °; the phases of the 4 dual-frequency radiation arms 22 are 0 degrees, 90 degrees, 180 degrees and 270 degrees, and the phases are respectively in one-to-one correspondence with the

feed points

14, 13, 12 and 11, so that the frequencies of a Beidou navigation system, a GPS navigation system and a GLONASS navigation system are realized.

As shown in fig. 3, the balun includes a first inductor, a second inductor, a first capacitor, a second capacitor, a grounding inductor, and a grounding capacitor; a first inductor and a second inductor are connected in series between an unbalanced port (namely, the port 1) and a first balanced port (namely, the port 2) of the balun, and a grounding capacitor is connected between the first inductor and the second inductor; a first capacitor and a second capacitor are connected in series between the unbalanced port and the second balanced port (namely, the port 3), and the grounding inductor is connected between the first capacitor and the second capacitor; one path is output by an indirect grounding capacitor in the two series inductors at the tail end inductor, the other path is output by the indirect grounding inductor in the two series capacitors at the tail end capacitor, signals are input from a single port (unbalanced port), two paths of signals with the same amplitude and opposite phases are output under the action of impedance conversion, the bandwidth is widened, the inductance and the capacitance in the balun structure are calculated through a theoretical formula, and the width and the length of a strip line in a 3dB bridge are adjusted, so that the integrally designed covering frequency band is 1561 MHz-1575 MHz and 2480 MHz-2500 MHz, and the problems that the basic LC balun is narrow in working bandwidth and can only work near the working frequency basically are solved.

In an embodiment of the present invention, the first inductor, the second inductor and the grounding inductor are all three-dimensional spiral structures to reduce the length of the inductor wire; the first capacitor, the second capacitor and the grounding capacitor are all parallel plate laminated capacitors in the vertical direction, and the 3dB bridge adopts a serpentine line as a coupling strip line so as to reduce the length of the strip line. In addition, both the balun and the 3dB bridge adopt an LTCC (low temperature co-fired ceramic) processing technology to further realize miniaturization.

In an embodiment of the present invention, the zigzag helix 21 and the straight helix 22 are metal wires.

Furthermore, the phase shifting feed network in this embodiment comprises one balun and two identical 3dB bridges. Considering factors such as size, coverage frequency band, bandwidth and the like, the balun part adopts a broadband form and comprises an unbalanced port and two balanced ports, the two balanced ports have a phase difference that an output port signal reaches 180 degrees and an output 3dB bridge part with the same amplitude at the same time of the two frequency bands and adopt a form of a broadside coupling bridge, and two signals which are mutually equal in amplitude and have a phase difference of 90 degrees are output. For example, a signal with an input impedance of 50ohm and a phase of 0 ° is first passed through a balun, and two constant amplitude signals with phases of 0 ° and 180 ° are output. The signal with the phase of 0 degree is used as an input signal of a 3dB bridge, and two signals with the phases of 0 degree and 90 degree respectively and with the same amplitude are output. The signal with the phase of 180 degrees is used as an input signal of another 3dB bridge, and two signals with the phases of 180 degrees and 270 degrees respectively and with equal amplitude are output. Generally speaking, inputting a signal with phase 0 ° and impedance of 50ohm, four signals with phase 0 °, 90 °, 180 °, 270 ° and equal amplitude are obtained.

The utility model discloses a miniaturized dual-frenquency circuit loading helical antenna, can realize the dual-frenquency radio communication of 1561MHz ~ 1575MHz frequency channel and 2480MHz ~ 2500MHz frequency channel simultaneously, and owing to adopt the dual-frenquency spiral arm of different lift angles and different linewidths of printing on flexible material, the quality is light, with low costs, and through the medium base plate that adopts two-sided printing, the one side is the feed network, including balun and 3dB electric bridge, the another side is four pads that link to each other with dual-frenquency radiation arm 2, simple structure, compactness have very high practical value under communication system miniaturization's trend day by day.

Those skilled in the art will appreciate that variations may be implemented by those skilled in the art in combination with the prior art and the above-described embodiments, and will not be described herein in detail. Such variations do not affect the essence of the present invention, and are not described herein.

The above description is directed to the preferred embodiment of the present invention. It is to be understood that the invention is not limited to the particular embodiments described above, and that devices and structures not described in detail are understood to be implemented in a manner common in the art; without departing from the scope of the invention, it is intended that the present invention shall not be limited to the above-described embodiments, but that the present invention shall include all the modifications and variations of the embodiments. Therefore, any simple modification, equivalent change and modification made to the above embodiments by the technical entity of the present invention all still fall within the protection scope of the technical solution of the present invention, where the technical entity does not depart from the content of the technical solution of the present invention.

Claims

1. A miniaturized, dual-band, circuit-loaded helical antenna, comprising: the circuit loading structure comprises a circuit loading structure, an insulating cylinder and 4 double-frequency radiating arms;

2. The miniaturized, dual-band, circuit-loaded helical antenna of claim 1, wherein the helix angles of said meandered helix and said straight helix are both 20-75 °.

3. The miniaturized dual-band circuit-loaded helical antenna of claim 1, wherein the widths of the meandered helix and the straight helix both range from 0.5mm to 1.5 mm.

4. The miniaturized dual-band circuit-loaded helical antenna of claim 1, wherein the feeding substrate has a double-sided structure, 4 pads and a feeding point are disposed on a lower surface of the feeding substrate, the 4 pads are respectively connected to the 4 feeding points through metallized through holes, the ends of the 4 dual-band radiating arms are respectively soldered to the 4 pads in a one-to-one correspondence, and the feeding point is used for connecting to a cable.

5. The miniaturized, dual-band, circuit-loaded helical antenna of claim 4, wherein said feed substrate is circular, and said phase-shifting feed network comprises an LTCC balun, 2 3dB bridges, and 4 said feed points;

6. The miniaturized, dual-band, circuit-loaded helical antenna of claim 5, wherein the LTCC balun comprises a first inductor, a second inductor, a first capacitor, a second capacitor, a ground inductor, and a ground capacitor;

7. The miniaturized, dual-band, circuit-loaded helical antenna of claim 1, wherein said dual-band radiating arm is printed on a layer of flexible material, said layer of flexible material being affixed to said dielectric cylinder.

8. The miniaturized, dual-band, circuit-loaded helical antenna of claim 7, wherein said layer of flexible material has a dielectric constant of 2-5.

9. The miniaturized, dual-band, circuit-loaded helical antenna of claim 7, wherein the layer of flexible material has a thickness of less than 0.5 mm.

10. The miniaturized dual band circuit-loaded helical antenna of claim 1, wherein said feeding substrate has a thickness of 0.5-2 mm.