CN212848805U - Beidou short message communication transceiving frequency reconfigurable antenna - Google Patents

Abstract

The utility model discloses a big dipper short message communication frequency of receiving and dispatching restructural antenna, the antenna comprises upper dielectric substrate, lower floor's dielectric substrate and radio frequency feed network dielectric substrate down in proper order from last, the main radiation paster is located the center of square ring parasitic radiation paster, radio frequency PIN diode loads between main radiation paster and parasitic radiation paster, direct current earthing terminal is connected along mid point department with parasitic radiation paster outer border through direct current earthing terminal lead wire, direct current offset terminal lead wire adopts the heterofacial form of putting to be connected to main radiation paster center. Compared with the prior art, the utility model discloses a frequency reconfiguration technique has realized that the structure of receiving and dispatching antenna medium base plate is multiplexing, and consequently required installation bore is little, has greatly reduced the volume and the weight of terminal equipment platform, to the equipment platform that has application demands such as low RCS and lightning protection, small-bore antenna has apparent inherent advantage.

Description

Beidou short message communication transceiving frequency reconfigurable antenna

Technical Field

The utility model relates to a communication field especially relates to a big dipper short message communication receiving and dispatching frequency restructural antenna, and the specially adapted has the big dipper short message terminal equipment platform among the airborne data communication system of small-bore, low profile conformal and low RCS application demand.

Background

The Beidou short message is a core characteristic function of the Beidou navigation system, supports the bidirectional communication capability of the short message, is not influenced by terrain conditions and environmental climate, is particularly suitable for data transmission in the case of being far away from a mobile communication network coverage area or mobile communication interruption caused by natural disasters and the like, and therefore has high military and civil values. Modern combat environments are increasingly complex, and the use of weaponry systems has increased in large numbers of electronic information devices, such as communications, radar detection, navigation, electronic countermeasure, and the like, resulting in an increasing number and variety of antennas. In order to reduce the weight and Radar Cross Section (RCS) of each electronic system on the equipment platform, it is urgently required to reduce the aperture and profile height of the antenna as much as possible without affecting the performance of the antenna.

The technology of the frequency reconfigurable antenna aims to enable the antenna to reconfigure the frequency characteristics of the antenna in real time according to actual needs, and dynamically changes the physical structure or size of the antenna by using a PIN or MEMS switch on the same antenna, so that the antenna has the functions of a plurality of antennas, namely that the plurality of antennas share one physical caliber. Through the frequency reconfigurable design, the required installation caliber of the antenna can be effectively reduced, and the space utilization rate of the equipment platform is improved. At present, the Beidou short message receiving and transmitting antenna is generally arranged in parallel by adopting two single-layer antennas for receiving and transmitting (see application publication No. CN 110954924A, the Beidou short message receiving and transmitting antenna arrangement in the patent application named as 'an integral anti-interference design method for Beidou satellite terminal equipment') or double-layer laminated arrangement (see patent publication No. CN 209282391U, the Beidou short message receiving and transmitting antenna arrangement in the patent named as 'a Beidou Bluetooth antenna'), but the former antenna has a larger aperture and is not beneficial to aperture comprehensive design, the latter antenna increases the profile height, and the total thickness of two layers of radiating sheet medium substrates of the antenna reaches 8mm, so the Beidou short message receiving and transmitting antenna is not suitable for low-profile conformal application, and the RCS is higher and can not meet the application requirements of low RCS. The Beidou short message receiving and sending frequency difference is large, low-profile common-caliber design can be carried out in a frequency reconfigurable mode, and meanwhile, the Beidou short message is used as an emergency standby function of the system and is generally in a receiving state, so that the Beidou short message receiving and sending system is suitable for receiving and sending time-sharing work. However, according to the current search discovery, no frequency reconfiguration research aiming at the Beidou short message transmitting and receiving antenna at home and abroad is found.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing a solve above-mentioned problem, the utility model discloses a low section, bore big dipper short message communication receiving and dispatching frequency reconfigurable antenna altogether are proposed for the first time, and antenna structure is simple, the stable performance, and easily engineering realizes. The antenna realizes low profile and miniaturization through structural multiplexing, and meanwhile, various electrical performance technical indexes such as voltage standing wave ratio, gain, axial ratio and the like have good performance in a receiving and transmitting frequency band.

In order to realize the purpose, the utility model discloses a technical scheme is: a Beidou short message communication transceiving frequency reconfigurable antenna comprises an antenna, wherein the antenna is sequentially composed of an upper dielectric substrate, a lower dielectric substrate and a radio frequency feed network dielectric substrate from top to bottom, the lower dielectric substrate is positioned between the upper dielectric substrate and the radio frequency feed network dielectric substrate, a direct current bias circuit on the lower surface of the upper dielectric substrate and a metal short circuit on the upper surface of the dielectric substrate of a feed network can be prevented,

the upper surface of the upper-layer dielectric substrate is provided with a square main radiation patch, a square annular parasitic radiation patch, a radio frequency PIN diode, a direct current offset end and a direct current grounding end, the main radiation patch is positioned in the center of the square annular parasitic radiation patch and positioned on a central normal line of the upper-layer dielectric substrate, the radio frequency PIN diode is loaded between the main radiation patch and the parasitic radiation patch, the direct current grounding end is connected with the midpoint of the outer edge of the parasitic radiation patch through a direct current grounding end lead, the direct current offset end is connected with the main radiation patch through a direct current offset end lead, the direct current offset end lead is connected to the center of the main radiation patch through two metalized through holes in an out-of-plane split mode, an antenna direct current offset circuit utilizes a printed circuit board metalized through hole technology to carry out wiring in an out in out-of-plane split mode, so that the direct current offset end lead can be connected to the center of the antenna main radiation patch from the bottom, based on the central zero-field-intensity channel of the microstrip antenna, the damage of a direct-current offset end lead wire to a circularly polarized radiation structure of the antenna is effectively avoided.

Preferably, a printed circuit board metalized via technology is utilized, a first metal via hole and a second metal via hole are formed in the upper-layer dielectric substrate, one end of the direct current offset end lead is connected with the direct current offset end, and the other end of the direct current offset end lead penetrates through the first metal via hole, penetrates through the second metal via hole and is connected with the center of the back of the main radiation patch along the lower surface of the upper-layer dielectric substrate. Therefore, the central zero-field-intensity channel of the microstrip antenna is utilized, and the influence of the lead wire of the direct-current offset end on the circular polarization radiation performance of the antenna is eliminated.

Preferably, the direct current offset end lead connected with the main radiating patch on the lower surface of the upper dielectric substrate is a direct current offset end lead tail section, and the direct current offset end lead tail section is perpendicular to the direct current ground end lead section in a non-coplanar manner. Thereby minimizing the effect of the dc bias circuit on the radiation characteristics of the antenna.

Preferably, choke inductors are loaded on the direct current bias terminal lead and the direct current ground terminal lead to suppress radio frequency current.

Preferably, the number of the radio frequency PIN diodes is 8, the radio frequency PIN diodes are uniformly loaded on the square annular slot sheet between the antenna main radiation patch and the parasitic radiation patch, the radio frequency PIN diodes are used for controlling the resonant frequency of the antenna radiation sheet, and more balanced gain of a receiving and transmitting frequency band can be obtained in the receiving and transmitting frequency band.

Preferably, the radio frequency feed network dielectric substrate is formed by laminating two layers of printed boards through prepregs, different feed networks are respectively adopted for antenna receiving and transmitting frequency bands of the radio frequency feed network dielectric substrate, each feed network comprises an L transmitting frequency band Wilkinson power divider, an S receiving frequency band Wilkinson power divider and a blocking capacitor so as to provide amplitude-phase balance corresponding to a corresponding circular polarization mode, and the L transmitting frequency band Wilkinson power divider and the S receiving frequency band Wilkinson power divider adopt a strip line mode.

Preferably, the whole antenna is of a cubic structure, three layers of printed boards, namely an upper layer dielectric substrate, a lower layer dielectric substrate and a radio frequency feed network dielectric substrate, are mounted on a metal floor through countersunk screws, the antenna adopts double feed probes, the two feed probes penetrate through the radio frequency feed network dielectric substrate and are welded on the back of the radio frequency feed network dielectric substrate, an SMP connector is embedded in the metal floor, and probes of the SMP connector penetrate through the radio frequency feed network dielectric substrate and are welded on the front of the radio frequency feed network dielectric substrate. And the upper layer medium substrate and the lower layer medium substrate are also provided with a cubic notch which is convenient for welding the probe of the SMP connector.

Preferably, the projections of the two feeding probes, the direct-current ground terminal lead and the tail of the direct-current bias terminal lead of the antenna on the metal floor are arranged in a cross shape, the center of the cross is positioned on a central normal of the dielectric substrate, the direct-current bias circuit of the antenna adopts an optimized layout to avoid a probe feeding area, and the direct-current ground terminal lead and the tail of the direct-current bias terminal lead are in a vertical relation, so that the influence of the direct-current bias circuit on the radiation characteristic of the antenna is minimized.

Preferably, the periphery of the radio frequency feed network dielectric substrate, the penetrating positions of the two feed probes and the back welding position of the blocking capacitor are provided with metalized through holes, the metalized through holes are connected with the upper surface metal layer and the lower surface metal layer so as to inhibit the generation of other mode transmission signals,

preferably, the metal layer on the upper surface of the radio frequency feed network dielectric substrate is an isolation ring which is etched around the bonding pads of the two feed probes, the two metalized through holes for blocking capacitance back welding and the SMP connector probes to prevent short circuit; and the metal layer on the lower surface of the radio frequency feed network dielectric substrate is provided with an isolation ring and a rectangular ring which are etched around the two feed probe pads, the blocking capacitor pad and the metalized through hole for installing the SMP probe and are used for preventing short circuit.

Compared with the prior art, the utility model has the advantages of:

(1) compare in the antenna that adopts the individual layer to independently arrange, the utility model discloses the antenna adopts frequency reconfigurable technique to realize the structure of receiving and dispatching antenna medium base plate and multiplex, and consequently required installation bore is little, has greatly reduced the volume and the weight of terminal equipment platform, simultaneously, to the equipment platform that has application demands such as low RCS and lightning protection, small-bore antenna has apparent inherent advantage.

(2) Compare in conventional double-deck stromatolite antenna, the utility model discloses the antenna is single layer construction, and radiation piece dielectric substrate section height has reduced half, can realize can be conformal with the installation cavity structure of antenna, has greatly reduced the structural discontinuity of antenna with metal installation cavity to reduce antenna section height, makeed its RCS performance to be showing and improve.

(3) The utility model discloses antenna radiation circular polarization electromagnetic wave, its radiation characteristic easily receives direct current bias circuit's influence, the utility model discloses antenna radio frequency PIN diode switch's direct current bias circuit adopts the different face to divide and puts the technique to utilize microstrip antenna center zero field strength characteristic, direct current offset end lead wire feeds through the radiation paster center from up down through two metallization via holes. Based on the design, the direct current bias circuit cannot damage the circularly polarized radiation structure of the antenna, so that the normal work of the antenna is ensured.

(4) The utility model discloses the break-make that the antenna passes through radio frequency PIN diode has realized that receiving and dispatching frequency is restructural, and antenna receiving and dispatching timesharing work has realized natural isolation between the receiving and dispatching antenna, has avoided transmitting system to the influence of receiving performance, has reduced the wave filter design degree of difficulty of antenna back level receiving and dispatching passageway, has guaranteed the good electromagnetic compatibility of receiving and dispatching antenna.

(5) The utility model discloses antenna theory of operation is clear, simple structure, and direct current bias circuit and antenna radiation piece are integrated to same medium base plate on, and simultaneously, the pad of choking inductance, blocking capacitor, two probes of antenna, SMP probe all is surface about the printing board of welding operation easily carries out, and all structures and the figure size on antenna printing board and metal floor all are far less than the limit and can realize the machining dimension, can realize low-cost and high accuracy production. When the antenna is designed, modeling is carried out according to the real object to the greatest extent, the simulation accuracy is high, the working frequency band of the antenna is wide, the electrical performance is stable, the work load of real object debugging is small, and engineering realization is easy.

(6) The utility model discloses can be applied to and be arranged in the airborne data communication system big dipper short message terminal equipment platform and other antenna fields that have similar performance requirement, can satisfy the application demand of small-bore, low profile conformal and low RCS.

Drawings

FIG. 1a is a diagram of a simulation model of an antenna operating in a transmitting L band (1615.68MHz +/-4.08 MHz), and FIG. 1b is a diagram of a simulation model of an antenna operating in a receiving S band (2491.75MHz +/-4.08 MHz);

fig. 2 (a) is a structural dimension diagram of the top layer of the upper dielectric substrate of the present invention; fig. 2 (b) is a structural dimension diagram of the bottom layer of the upper dielectric substrate of the present invention;

fig. 3 (a) is a structural dimension diagram of the top layer of the lower dielectric substrate according to the present invention; fig. 3 (b) is a structural dimension diagram of the bottom layer of the lower dielectric substrate of the present invention;

fig. 4 (a) is a structural size diagram of the top layer of the feed network dielectric substrate of the antenna of the present invention in the transmission L frequency band; fig. 4 (b) is a structural size diagram of the feeding network dielectric substrate middle layer of the antenna of the present invention in the transmitting L frequency band; fig. 4 (c) is a structural size diagram of the bottom layer of the feed network dielectric substrate of the antenna of the present invention in the transmission L frequency band;

fig. 5 (a) is a structural size diagram of the top layer of the feed network dielectric substrate in the S-band of the antenna of the present invention; fig. 5 (b) is a structural size diagram of the feeding network dielectric substrate middle layer of the antenna of the present invention in the receiving S frequency band; fig. 5 (c) is a structural size diagram of the feed network dielectric substrate bottom layer of the antenna of the present invention in the receiving S frequency band;

fig. 6a is an equivalent circuit model of the rf PIN diode (SMP 1345-; FIG. 6b is an equivalent circuit model of the radio frequency PIN diode (SMP 1345 and 079LF) adopted by the antenna of the present invention in the cut-off state;

fig. 7a shows the electric field distribution of the antenna when the PIN diode of the present invention is turned on; fig. 7b shows the electric field distribution of the PIN diode antenna when it is turned off;

fig. 8a is a voltage standing wave ratio simulation curve diagram of the simulated voltage standing wave ratio of the antenna working in the transmitting frequency band of the present invention varying with the frequency; fig. 8b is a voltage standing wave ratio simulation curve diagram of the simulated voltage standing wave ratio of the antenna working in the receiving frequency band varying with the frequency;

fig. 9a is a graph of the main and cross-polarized radiation patterns in the XZ plane when the antenna is operating at a center frequency of 1615.68MHz in the transmit band; fig. 9b is a graph of the main and cross-polarized radiation patterns in the YZ plane for the antenna operating at a center frequency of 1615.68MHz in the transmit band; fig. 9c is a graph of the main and cross-polarized radiation patterns in the XZ plane when the antenna is operating at a center frequency of 2491.75MHz in the receive band; fig. 9d shows the main polarization and cross polarization radiation patterns in YZ plane, respectively, when the antenna is operated at a center frequency of 2491.75MHz in the receive band; in the figure, the antenna of the utility model is a simulated radiation directional diagram of the receiving and transmitting center frequency, the solid line represents a left-handed circular polarization directional diagram, and the dotted line represents a right-handed circular polarization directional diagram;

fig. 10a is a simulation graph of gain and axial ratio when the antenna of the present invention operates in the transmission frequency band; fig. 10b is a graph showing simulation curves of gain and axial ratio when the antenna of the present invention operates in the receiving frequency band.

In the figure: 1 upper dielectric substrate, 2 lower dielectric substrate, 3 radio frequency feed network dielectric substrate, 4 countersunk screws, 5 metal floor, 6 main radiation patch, 7 parasitic radiation patch, 8 square ring gap, 9 radio frequency PIN diode, 10 choking inductance, 11 direct current grounding end, 12 direct current offset end, 13 direct current grounding end lead, 14 direct current offset end lead, 15 direct current offset end lead tail section, 16L transmitting frequency band Wilkinson power divider, 17 blocking capacitor, 18 feed probe, 19 first metalized through hole, 20 second metalized through hole, 21 cubic gap, 22S receiving frequency band Wilkinson power divider, 23 metalized through hole and 24SMP connector.

Detailed Description

The present invention will be further explained below.

Example 1: a Beidou short message communication transceiving frequency reconfigurable antenna is shown in figure 1 and comprises an antenna, wherein the antenna is composed of an upper layer medium substrate 1, a lower layer medium substrate 2 and a radio frequency feed network medium substrate 3 from top to bottom in sequence, three layers of printed boards are installed on a metal floor 5 through countersunk screws 4, the antenna is integrally of a cubic structure, the upper surface of the upper layer medium substrate 1 is provided with a square main radiation patch 6, a square annular parasitic radiation patch 7, a radio frequency PIN diode 9, a direct current offset end 12 and a direct current grounding end 11, the main radiation patch 6 is positioned at the center of the square annular parasitic radiation patch 7, the radio frequency PIN diode 9 is loaded between the main radiation patch 6 and the parasitic radiation patch 7, the direct current grounding end 11 is connected with the midpoint of the outer edge of the parasitic radiation patch 7 through a direct current grounding end lead 13, the direct current offset end 12 is connected with the main radiation patch 6 through a direct current offset end lead 14, the direct current offset end lead 14 is connected to the center of the main radiation patch 6 through two metalized through holes in a non-coplanar split mode

The square main radiation patch 6 and the square annular parasitic radiation patch 7 loaded around are connected through 8 radio frequency PIN diodes 9, and the resonance frequency of the antenna radiation patch is changed by controlling the connection and disconnection states of the radio frequency PIN diodes 9, so that the reconfigurable characteristics of the antenna in a receiving S frequency band (2491.75MHz +/-4.08 MHz) and a transmitting L frequency band (1615.68MHz +/-4.08 MHz) are realized. The DC bias circuit is composed of a DC bias end 12, a DC ground end 11 and metal leads thereof, and the DC bias and ground input ports are positioned on the top layer of the first dielectric plate of the antenna. In order to avoid the influence of the direct current bias circuit on the radiation characteristic of the antenna, the direct current ground terminal lead 13 is directly connected with the parasitic radiation patch 7, and the direct current bias terminal lead 14 is connected to the center of the main radiation patch 6 through two metalized through holes in an out-of-plane split mode. A choke inductor 10 is respectively loaded on the leads of the dc bias terminal 12 and the dc ground terminal 11 to prevent the rf signal from flowing to the dc path. The antenna adopts a double-point feed structure, and in order to facilitate the test and verification of the double-frequency double-circular polarization radiation characteristic of the antenna, two independent Wilkinson power dividers are introduced to serve as a radio frequency feed network so as to respectively realize the right-hand circular polarization characteristic of the antenna at a receiving S frequency band and the left-hand circular polarization characteristic of an emitting L frequency band. In addition, a direct current blocking capacitor 17 is loaded between the antenna radio frequency input total port and the Wilkinson power divider to prevent direct current signals from flowing into a radio frequency channel, and simultaneously, the transmission of radio frequency current is not blocked.

The antenna upper dielectric substrate 1 has dimensions of 60mm × 60mm × 2mm, see fig. 2. The dielectric substrate is made of TP-2 material with dielectric constant of 10.2 and loss tangent of 0.0023. An antenna radiation patch is printed on the upper surface of the antenna radiation patch, the size of the antenna radiation patch is 27.25mm multiplied by 27.25mm, and the antenna radiation patch is divided into a main radiation patch 6 and a parasitic radiation patch 7 by etching a square annular slot piece 8 (the width is 1mm) inside the antenna radiation patch. 8 radio frequency PIN diodes 9 are uniformly loaded on a square annular gap sheet 8 between the antenna main radiation patch 6 and the parasitic radiation patch 7, when the radio frequency PIN diodes 9 are conducted, the antenna works in an L transmission frequency band (1615.68MHz +/-4.08 MHz), when the radio frequency PIN diodes 9 are disconnected, the antenna works in an S receiving frequency band (2491.75MHz +/-4.08 MHz), the type of the radio frequency PIN diodes 9 is SMP 1345 + 079LF, the working frequency of the radio frequency PIN diodes is 10MHz-6 GHz, the radio frequency PIN diodes cover a short message receiving and transmitting frequency band, and the size of the radio frequency PIN diodes is 1.6mm multiplied by 0.8mm multiplied by 0.6 mm. In order to make the design closer to the actual situation, the detailed equivalent parameters of the rf PIN diode 9 in the on and off states need to be substituted in the antenna simulation, as shown in fig. 6.

The dc bias terminal 12 and the ground terminal 11 are located on the top layer of the first dielectric plate of the antenna, and have a size of 3mm × 3 mm. The dc ground lead 13 is directly connected to the outer edge of the parasitic radiating patch 7 at its midpoint. The direct current offset end lead 14 is connected to the center of the main radiation patch 6 through two metalized through holes with the diameter of 0.4mm by adopting a different-surface split mode. The dc-biased terminal lead 14 and the ground terminal lead 13 are structurally thin conductive strips of metal having a width of 0.2 mm. In order to prevent radio frequency signals from flowing to a direct current path, a choke inductor 10 is respectively loaded on a direct current bias terminal lead 14 and a grounding terminal lead 13, the distance between the two inductors and the edge of a printed board is 7mm and 13mm respectively, the inductance value is 0.685uH, and the size is 2mm multiplied by 1.25 mm.

The size of the lower dielectric substrate 2 and the substrate material used are the same as those of the upper dielectric substrate 1, see fig. 3. The upper surface of the copper layer is free of metal patterns, and the copper layer on the upper surface needs to be completely corroded during manufacturing; the copper layer on the lower surface of the dielectric substrate is basically reserved, but an isolation ring needs to be etched around the two probes to prevent short circuit, meanwhile, the isolation ring needs to be etched right above two metalized through holes 23 with the diameter of 0.6mm in the radio frequency feed network dielectric substrate 3 to prevent short circuit, and the blocking capacitor 17 can be welded on the back surface of the feed network printed board through the two metalized through holes 23. The metal layer on the lower surface of the antenna lower dielectric substrate 2 actually plays a role of the metal floor 5, and forms a typical dual-linear polarization microstrip resonant antenna together with the antenna radiation patch, the antenna two-layer dielectric substrate and the two feed probes 18.

The antenna receiving and transmitting frequency bands of the radio frequency feed network dielectric substrate 3 respectively adopt different feed networks, referring to fig. 4 and 5, and the feed networks comprise an L transmitting frequency band Wilkinson power divider 16, an S receiving frequency band Wilkinson power divider 22 and a blocking capacitor 17; the Wilkinson power divider of the antenna radio frequency feed network adopts a strip line form, the total size of a dielectric substrate of the Wilkinson power divider is 60mm multiplied by 2.1mm, two layers of printed boards with the thickness of 1mm (the material is TC350 material with the dielectric constant of 3.5 and the loss tangent value of 0.003) are pressed through prepregs, and the type of an adhesive sheet used for compression joint is Rogers 4450F, the dielectric constant of 3.48, the loss tangent value of 0.004 and the thickness of 0.1 mm. The dielectric substrate comprises three metal layers, copper layers of the metal layers on the upper surface and the lower surface are basically reserved, and the middle layer is a Wilkinson power divider. It should be noted that the two feed probes 18 of the antenna need to pass through the radio frequency feed network dielectric substrate 3 and be welded on the back surface of the dielectric substrate, while the probe of the antenna SMP connector 24 passes through the radio frequency feed network dielectric substrate 3 and is welded on the front surface of the dielectric substrate, and meanwhile, the two layers of dielectric substrates of the antenna are designed with a cubic notch 21 which is positioned right above the probe welding point of the SMP connector 24 so as to weld the probe of the SMP connector 24. The metal layer on the upper surface of the dielectric substrate needs to etch an isolation ring around the bonding pads of the two feed probes 18, the two metalized through holes 23 for back welding of the blocking capacitor 17 and the probes of the SMP connector 24 to prevent short circuit; the dielectric substrate lower surface metal layer needs to etch isolation circular and rectangular rings around the two feed probe 18 pads, dc blocking capacitor 17 pads, and SMP probe mounting metalized through holes 23 to prevent shorting. The value of the blocking capacitor 17 is 1uF, and the size is 2mm multiplied by 1.25mm multiplied by 1.3 mm. In addition, 71 metallized through holes 23 with the diameter of 0.6mm and the interval of 3mm are connected with the upper and lower surface metal layers so as to inhibit the generation of transmission signals of other modes.

The metal floor 5 of the antenna is made of aluminum alloy, the size of the metal floor is 60mm multiplied by 5mm, the SMP radio frequency connector is embedded into the metal floor 5, and the antenna feed network is fed in a back feed mode. A cylindrical hole and a cubic hole are designed in the metal floor 5 just below the two feed probes 18 and the dc blocking capacitor 17 of the antenna, respectively, to prevent short circuits.

The main structural parameters of the antenna are shown in fig. 2, the structural parameters of the antenna are more, the antenna achieves the best performance through a large number of parameter designs and optimizations, and the detailed dimensions are as follows (unit: mm):

parameter(s)	W1	W2	W3	W4	W5	W6	W7	W8
									Numerical value	60	27.25	1	13	3	7	52	0.2
Parameter(s)	W9	W10	W11	W12	W13	W14	W15	W16
									Numerical value	3.6	0.57	13	21.2	5	3.9	9	9.1
Parameter(s)	W17	W18	W19	W20	W21	W22	L1	L2
									Numerical value	4	1.2	13.4	3	3	3.25	60	3
Parameter(s)	L3	L4	R1	R2	R3	R4	R5	R6
									Numerical value
	3	2.1	1.25	0.2	0.2	0.25	1	0.8
									Parameter(s)	R7	R8	R9	R10	R11	R12	R13	R14
Numerical value	0.8	0.3	0.35	0.9	1.4	0.7	0.3	0.8

The Beidou short message communication transceiving frequency reconfigurable antenna has the following working principle: the antenna radiation part adopts a dual-polarized microstrip patch antenna, the radiation patch is designed into a main radiation patch 7 and a parasitic radiation patch 7, 8 radio frequency PIN diodes 9 are uniformly loaded at the gap between the main radiation patch and the parasitic radiation patch, and the physical structure of the antenna can be changed through the connection and disconnection states of the diodes based on the above, so that the current distribution on the antenna radiation surface is changed, and the resonant frequency of the antenna is changed. The radio frequency PIN diode 9 feeds power by adopting a direct current feed circuit, and when a positive voltage is applied, the radio frequency PIN diode 9 is conducted; when a negative voltage is applied or not powered, the rf PIN diode 9 is diode off. The direct current bias circuit applies voltage to the right center of the antenna radiation piece by adopting a non-coplanar split structure, and minimizes the influence of a direct current feed circuit on the antenna radiation structure by utilizing a zero-field-intensity channel at the center of the microstrip patch and further optimizing the arrangement, thereby ensuring that the circular polarization radiation characteristic of the antenna is not deteriorated. The antenna feed part adopts a Wilkinson power divider (in a strip line form) to provide amplitude-phase characteristics required by two feed points of the antenna, thereby realizing circular polarization radiation characteristics. In addition, by loading the choke inductor 10 on the direct current bias end lead 4 and the ground end lead 13 and loading the direct current blocking capacitor 17 between the antenna radio frequency input port and the Wilkinson power divider, the influence of direct current signals and radio frequency signals on each other is effectively isolated, and good electromagnetic compatibility is ensured.

The effect of the utility model can be further explained by combining the simulation result:

1. emulated content

1.1 the commercial electromagnetic simulation software ANSYSY HFSS _15.0 is used to perform simulation calculation on the distribution of the antenna electric field when 8 rf PIN diodes 9 of the antenna of the present invention are operated in the on and off states, and the results are shown in fig. 7(a) and 7 (b).

1.2 the voltage standing wave ratio of the antenna of the present invention operating in the transmitting and receiving frequency bands is simulated by commercial electromagnetic simulation software ANSYSY HFSS _15.0, and the results are shown in fig. 8(a) and 8 (b).

1.3 the radiation pattern of the antenna of the present invention operating at the transmit-receive center frequency was simulated by commercial electromagnetic simulation software ANSYSY HFSS _15.0, and the results are shown in fig. 9(a), 9(b), 9(c) and 9 (d).

1.4 the commercial electromagnetic simulation software ANSYSY HFSS _15.0 is used to perform simulation calculation on the variation of gain and axial ratio with frequency when the antenna of the present invention operates in the transmitting and receiving frequency bands, and the results are shown in fig. 10(a) and 10 (b).

2. Simulation result

Referring to fig. 7, as can be seen from fig. 7(a), the electric field is mainly distributed on the parasitic radiation patch 7, the current path is long, and the antenna operates in the transmission low frequency band; fig. 7(b) shows that the electric field is mainly distributed on the main radiating patch 6, the current path is short, and the antenna operates in the high receiving band.

Referring to FIG. 8, with VSWR ≦ 2 as a standard, it can be seen from FIG. 8(a) that the relative bandwidth of the voltage standing wave ratio is about 5.3% (1.569GHz-1.655GHz) when the antenna is operated in the transmitting state, and it can be seen from FIG. 8(b) that the relative bandwidth of the voltage standing wave ratio is about 5.4% (2.436GHz-2.57GHz) when the antenna is operated in the receiving state. Meanwhile, the voltage standing wave ratio of the antenna in a transmitting L frequency band (1615.68MHz +/-4.08 MHz, relative bandwidth is about 0.33%) is not more than 1.3, and the voltage standing wave ratio of the antenna in a receiving S frequency band (2491.75MHz +/-4.08 MHz, relative bandwidth is about 0.51%) is not more than 1.3.

Referring to fig. 9, it can be seen from fig. 9(a) and 9(b) that the antenna radiates left-handed circular polarized wave when operating at 1615.68MHz, the antenna normal main polarization gain is 4.05dBic, the corresponding right-handed circular polarization gain is-26.41 dBic, and it can be seen from fig. 9(c) and 9(d) that the antenna radiates right-handed circular polarized wave when operating at 2491.75MHz, the antenna normal main polarization gain is 3.62dBic, and the corresponding left-handed circular polarization gain is-30.26 dBic, so the antenna of the present invention has good circular polarization purity.

Referring to FIG. 10, with AR ≦ 3dB as a standard, it can be seen from FIG. 10(a) that the axial ratio relative bandwidth is about 1.1% (1.605GHz-1.623GHz) when the antenna is operating in the transmit state, the antenna gain is 3.9 dBic-4.05 dBic in this bandwidth, and it can be seen from FIG. 10(b) that the axial ratio relative bandwidth is about 1.6% (2.469GHz-2.508GHz) when the antenna is operating in the transmit state, the antenna gain is 3.22 dBic-3.67 dBic in this bandwidth. Simultaneously, the antenna is not more than 1.9dB at the internal shaft ratio of transmission L frequency channel (1615.68MHz +/-4.08 MHz), and the gain is 4.03 dBi-4.04 dBi-c, and the antenna is not more than 0.9dB at the internal shaft ratio of receiving S frequency channel (2491.75MHz +/-4.08 MHz), and the gain is 3.55 dBi-3.65 dBi-c, consequently, the utility model discloses the antenna has fine shaft ratio characteristic and stable gain characteristic in the operating band.

The big dipper short message communication transceiving frequency reconfigurable antenna provided by the utility model is introduced in detail, and the specific examples are applied to explain the principle and the implementation mode of the utility model, and the description of the above embodiments is only used for helping understanding the method and the core idea of the utility model; while the invention has been described in terms of specific embodiments and applications, it will be apparent to those skilled in the art that numerous variations and modifications can be made without departing from the spirit and scope of the invention as defined in the appended claims.

Claims (10)

1. The utility model provides a big dipper short message communication receiving and dispatching frequency reconfigurable antenna, includes the antenna, its characterized in that: the antenna is composed of an upper-layer dielectric substrate (1), a lower-layer dielectric substrate (2) and a radio frequency feed network dielectric substrate (3) from top to bottom in sequence, wherein a square main radiation patch (6), a square annular parasitic radiation patch (7), a radio frequency PIN diode (9), a direct current bias end (12) and a direct current grounding end (11) are arranged on the upper surface of the upper-layer dielectric substrate (1), the main radiation patch (6) is located at the center of the square annular parasitic radiation patch (7), the radio frequency PIN diode (9) is loaded between the main radiation patch (6) and the parasitic radiation patch (7), the direct current grounding end (11) is connected with the midpoint of the outer edge of the parasitic radiation patch (7) through a direct current grounding end lead (13), and the direct current bias end (12) is connected with the main radiation patch (6) through a direct current bias end lead (14), the direct current offset end lead (14) is connected to the center of the main radiation patch (6) through two metalized through holes in a non-coplanar split mode.

2. The Beidou short message communication transceiving frequency reconfigurable antenna according to claim 1, characterized in that: the radiating patch is characterized in that a first metal through hole (19) and a second metal through hole (20) are formed in the upper-layer dielectric substrate (1), one end of a direct current offset end lead (14) is connected with a direct current offset end (12), and the other end of the direct current offset end lead (14) penetrates through the first metal through hole (19) and is connected with the center of the back of the main radiating patch (6) along the lower surface of the upper-layer dielectric substrate (1) and penetrates through the second metal through hole (20).

3. The Beidou short message communication transceiving frequency reconfigurable antenna according to claim 2, characterized in that: and a direct current offset end lead (14) which is arranged on the lower surface of the upper-layer dielectric substrate (1) and connected with the main radiation patch (6) is a direct current offset end lead tail section (15), and the direct current offset end lead tail section (15) is vertical to the direct current grounding end lead (13) in a non-coplanar manner.

4. The Beidou short message communication transceiving frequency reconfigurable antenna according to claim 2, characterized in that: and a choking inductor (10) is loaded on the direct current offset terminal lead (14) and the direct current grounding terminal lead (13).

5. The Beidou short message communication transceiving frequency reconfigurable antenna according to claim 1, characterized in that: the number of the radio frequency PIN diodes (9) is 8, and the radio frequency PIN diodes are uniformly loaded on a square annular gap sheet (8) between the antenna main radiation patch (6) and the parasitic radiation patch (7).

6. The Beidou short message communication transceiving frequency reconfigurable antenna according to claim 1, characterized in that: the radio frequency feed network dielectric substrate (3) is formed by laminating two layers of printed boards through prepregs, different feed networks are respectively adopted for antenna receiving and transmitting frequency bands of the radio frequency feed network dielectric substrate (3), the feed networks comprise L transmitting frequency band Wilkinson power dividers (16), S receiving frequency band Wilkinson power dividers (22) and blocking capacitors (17), and the L transmitting frequency band Wilkinson power dividers (16) and the S receiving frequency band Wilkinson power dividers (22) are in strip line forms.

7. The Beidou short message communication transceiving frequency reconfigurable antenna according to claim 3, characterized in that: the antenna is integrally of a cubic structure, three layers of printed boards including an upper dielectric substrate (1), a lower dielectric substrate (2) and a radio frequency feed network dielectric substrate (3) are mounted on a metal floor (5) through sunk screws, the antenna adopts double feed probes (18), the two feed probes (18) penetrate through the radio frequency feed network dielectric substrate (3) and are welded to the back of the radio frequency feed network dielectric substrate (3), SMP connectors (24) are embedded in the metal floor (5), and probes of the SMP connectors (24) penetrate through the radio frequency feed network dielectric substrate (3) and are welded to the front of the radio frequency feed network dielectric substrate (3).

8. The Beidou short message communication transceiving frequency reconfigurable antenna according to claim 7, wherein: the projections of two feed probes (18), a direct current grounding end lead (13) and a direct current offset end lead tail (15) of the antenna on the metal floor (5) are arranged in a cross shape, and the center of the cross is positioned on a central normal line of the dielectric substrate.

9. The Beidou short message communication transceiving frequency reconfigurable antenna according to claim 7, wherein: metallized through holes (23) are formed in the periphery of the radio frequency feed network dielectric substrate (3), the penetrating positions of the two feed probes (18) and the back welding position of the blocking capacitor (17), and the metallized through holes (23) are connected with the upper surface metal layer and the lower surface metal layer.

10. The Beidou short message communication transceiving frequency reconfigurable antenna according to claim 9, wherein: an isolation ring for preventing short circuit is etched on the upper surface metal layer of the radio frequency feed network dielectric substrate (3) around the bonding pads of the two feed probes (18), the two metallized through holes (23) for back welding of the blocking capacitor (17) and the probes of the SMP connector (24); and the lower surface metal layer of the radio frequency feed network dielectric substrate (3) is provided with an isolation ring and a rectangular ring which are etched around the two feed probe (18) pads, the blocking capacitor (17) pads and the metalized through hole (23) for mounting the SMP probe and are used for preventing short circuit.

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