Broadband microstrip antenna system with low sensitivity to multibeam reception

FIELD: physics, communications.

SUBSTANCE: invention relates to broadband microstrip antenna systems with low sensitivity to multibeam reception. The broadband microstrip antenna system has an earthing plane comprising: a first surface having a first cross dimension; and a cavity filled with air, wherein the cavity has a second surface having a second cross dimension; and a side wall surface having a first height; and a radiating element having a third cross dimension, wherein the radiating element is placed crosswise within the cavity, has a second a second height from the first surface, wherein the second height is greater than zero but not more than 0.05λ, where λ is the wavelength in free space for the broadband microstrip antenna system, and has a third height from the second surface, and is separated from the earthing plane by air; and a conductor connected to the radiating element and configured to feed electromagnetic signals into the radiating element.

EFFECT: obtaining a small-size broadband microstrip antenna system with a wide bandwidth and low sensitivity to multibeam reception.

17 cl, 18 dwg

The prior art INVENTIONS

The present invention generally relates to antennas and, more particularly, to a broadband microstrip (micropatch) antenna systems with low sensitivity to multipath reception.

Microstrip antennas (MPA) is widely distributed in the receiver of a global navigation satellite system (GNSS). In comparison with other designs of antennas they are small, are light weight and can be manufactured in large quantities at low cost. The main elements of the traditional MPA are flat radiating element (strips) and flat screen plane separated by a dielectric medium. Resonance MPA size is a function of the wavelength of the radiation propagating in the dielectric medium between the radiating element and the shielding plane. Resonance approximately equal to half the wavelength. Resonant size can be reduced by increasing the dielectric constant of the dielectric environment or introducing slow wave structure. The reduction of the resonant size also leads to a broader pattern of the antenna, which is preferred for some applications.

The size of the MPA is also determined by other design considerations. In traditional MPA size shielding plane is usually more is whether equal to λ, where λ is the wavelength of interest to radiation in free space. Large shielding plane is used to reduce the signals reflected from the soil under the antenna. Additionally, in MPA band width increases with the height of the radiating element above the shielding plane. In order to achieve a bandwidth of 12% or more, the height is equal to ~(0,10-0,15)λ. Here the bandwidth is specified as a percentage of the center frequency corresponding to λ. In addition to increasing the overall size of the antenna required the specified height, however, also leads to increased radiation pattern in the opposite hemisphere and higher sensitivity to multipath reception. High sensitivity to multipath reception becomes significant when the length of the shielding plane is of the order of 1-1 .5 wavelength.

Figure 1 shows a microstrip antenna corresponding to the previous level of technology development, to reduce sensitivity to multipath reception. Microstrip antenna is a microstrip antenna formed on a dielectric substrate 110. On top of the dielectric substrate 110 are strip antenna elements 104. Under the dielectric substrate 110 is shielding plane 102 containing edge baffle elements 108. The point 106 of the coaxial connection is ider is attached to the strip antenna elements 104. Coreconnection (not shown) connects the strip antenna elements 104 to the shielding plane 102.

Regional baffle elements 108 form a vertical rim around the edge of the dielectric substrate 110 and protrude above the top surface of the dielectric substrate 110. In one embodiment, part of the boundary of the shielding elements 108 contain the connection through holes located near the edge of the dielectric substrate 110. The interval between the holes has a certain value, much smaller than the wavelength. Presumably, the design of the boundary of the shielding elements 108 creates significant filtering of multibeam radiation propagating below the horizon. This design microstrip antennas corresponding to the prior art, suffers, however, a serious disadvantage: reduced sensitivity to multipath reflection is inefficient in the case of a broadband emitter lengths of the shielding plane about 1-1 .5 wavelength. A large bandwidth is achieved by increasing the height of the strip elements 104 of the antenna above the shielding plane 102, which results in an increased sensitivity to multipath reflection.

The challenge is in getting broadband microstrip antenna system of small size with a wide (RBW is bandwidth and low sensitivity to multipath reception.

A BRIEF summary of the INVENTION

In the embodiment of the present invention broadband microstrip antenna system has a shielding plane containing the first surface and the cavity. The cavity contains the second surface and the surface of the side wall. A radiating element is located in the transverse direction inside the cavity and has a height above the first surface and the height above the second surface. Large bandwidth and low sensitivity to multipath radiation can be achieved by changing the height above the first surface and the height above the second surface. In a preferred embodiment, the height above the second surface is not more than 0,05λ, where λ is the wavelength in free space. In another embodiment of the invention a dual-band microstrip antenna system with a large bandwidth and low sensitivity to multipath radiation can be achieved by applying a second radiating element on top of the first radiating element.

These and other advantages of the invention will be obvious to a person skilled in the art upon reference to the subsequent detailed description and the accompanying drawings.

BRIEF DESCRIPTION of DRAWINGS

Figure 1 - design of microstrip antennas that meet the General prior art;

Figure 2 - schematic representation of microstrip antennas;

Figure 3 is a schematic depiction dual-band microstrip antennas;

4 is a reference rectangular coordinate system for the radiation down/up;

Figa and FIGU - schematic representation of the mathematical model of microstrip antennas

6 is a graphic pattern as a function of angle;

Fig.7 - graphics relations radiation up and down as a function of angle;

Fig graphics relations radiation up/down D/U(90) as a function of the length of the shielding plane;

Fig.9 - graphics comparison pattern as a function of angle for a flat shielding plane relative to the shielding plane with the cavity;

Figure 10 is a graphic comparison of the relationship of radiation up and down as a function of angle for a flat shielding plane relative to the shielding plane with the cavity;

Figa - reference rectangular coordinate system for broadband microstrip antenna systems;

Figw-11E is a schematic depiction of a broadband microstrip antenna systems corresponding to variants of the invention;

Fig is a schematic depiction of a dual-band microstrip antenna system corresponding to the variant embodiment of the invention; and

Fig - schematic representation dvdheaven the second microstrip antenna system with slow wave structures in accordance with the embodiment of the invention.

DETAILED DESCRIPTION

Figure 2 presents a view in cross section of a conventional microstrip antenna. Flat radiating element (strips) 202 is separated from the flat shielding plane 204 of the dielectric medium 212. The dielectric medium 212 can be, for example, an air gap or solid dielectric substrate. If the dielectric medium 212 is an air gap, a radiating element 202 and the shielding plane 204 can knit together by pins, such as ceramic bars (not shown). The length of the shielding plane 204 is equal to L. the Height of the radiating element 202 on the shielding plane 204 is equal toH. If the dielectric medium 212 is air, the height H is equivalent to the width of the air gap between the radiating element 202 and the shielding plane 204. If the dielectric medium 212 is a solid dielectric substrate, the height H is equivalent to the thickness of the solid dielectric substrate.

The signals are transmitted to the microstrip antenna and from it via radio frequency (RF) transmission line. In the example shown in figure 2, the signals are fed to the radiating element 202 through a coaxial cable. Outer conductor 206 is electrically connected to the shielding plane 204, and the Central conductor 208 is electrically connected to radiating element 202. Electromagnetic signals are fed to the suc is the overarching element 202 through the Central conductor 208. Electric currents are induced as sluchayem element 202, and the shielding plane 204.

The resonant size of the microstrip antenna is determined by the wavelength of radiation propagating in the dielectric medium 212 between the radiating element 202 and the shielding plane 204. Resonance approximately equal to a half wavelength in the dielectric medium 212. To reduce the wavelength in the dielectric medium 212, the dielectric constant of the dielectric medium 212 can be increased or between the radiating element 202 and the shielding plane 204 can be entered slow wave structure. Using these tools, the antenna pattern can be extended and resonant size may be reduced.

Figure 3 presents a view in cross-section dual-band longline microstrip antenna operating in two frequency bands. Configuration for the lower band similar to that shown in figure 2. A radiating element 302 is separated from the shielding plane 304 dielectric medium 312, which may be, for example, air or a solid dielectric. The signals are transmitted to the microstrip antenna and received from the RF transmission line. In the example shown in figure 3, the signals are fed to the radiating element 302 through a coaxial cable. External is Robotnik 306 is electrically connected to the shielding plane 304, and the center conductor 308 is electrically connected with the radiating element 302.

For the upper frequency band radiating element 322 is separated from the radiating element 302 dielectric medium 332, which may be, for example, air or a solid dielectric. A radiating element 322 is fed by a conductive element 328 connection, electrically connected to the radiating element 302, which serves as a shielding plane for the radiating element 322. As discussed above, a radiating element 302 and the shielding plane 304 may be fastened by pins (such as ceramic bars); similarly, a radiating element 322 and a radiating element 302 can be fastened with pins. As shown in figure 3, the length of the shielding plane 304 is equal to L; the height of the radiating element 302 over the shielding plane 304 is equal to H1, the height of the radiating element 322 above the radiating element 302 is equal to H2; and the total height of the radiating element 322 on the shielding plane 304 is equal to H=H1+H2.

Figure 4 shows the geometric orientation of a single-band microstrip antenna relative to a rectangular coordinate system defined by the axis 401 x axis 403 y and axis z 405. Direction +y points in the plane of the drawing. Outdoors the direction of +z (up) (Zenith) points to the sky and the direction-z (down) points in the direction of the Earth. Here, the term "Earth" with the contains as land, and the aquatic environment. To avoid confusion with "electrical" ground (used to refer to the screen plane), the concept of "geographic" earth used to refer to the land) are not used. Figure 4 microstrip antenna 402 includes a radiating element 404 and the shielding plane 406. In this example, the shielding plane 406 is larger than the radiating element 404. To simplify the drawing, other components, such as coaxial cable feeder, the dielectric medium and the pins, not shown.

Figure 4 electromagnetic waves are represented as rays falling on microstrip antenna 402 at an angle θ of incidence relative to the axis 401 x. The horizon corresponds to θ = 0 degrees; Zenith corresponds to θ = 90 degrees. Rays falling from the open sky, such as the beam 431, have positive values of angle of incidence. The rays reflected from the earth, such as the beam 441, have negative values of angle of incidence. Here the area of the space with positive values of the angle of incidence is referred to as the region of the direct signal and is also referred to as the forward hemisphere. Here, the region of space with negative values of the angle of incidence is referred to as the area of multipath signal and is also referred to as the rear hemisphere.

To numerically describe the ability of the antenna to suppress the reflected signal, usually used in isoamsa the following relationship: The parameter D/U(θ) (the ratio of radiation downwards/upwards) equal to the level of F(θ) of the antenna directional diagram in the rear hemisphere to the level of F(θ) of the antenna directional diagram in the front hemisphere under the mirror angle, where F represents the voltage level.

Returning to figure 2, the bandwidth of a single-band microstrip antenna is a function of the height H of the radiating element 202 on the shielding plane 204. Band width increases with increasing H. the width of the strip about 12% of the height H is approximately (0,10-0,15)λ. Here, the bandwidth is specified as a percentage of the center frequency corresponding to λ, where λ is the wavelength of the radiation of the antenna in free space. To simplify the terminology used here, the wavelength of radiation of the antenna in free space is referred to as wavelength antenna in free space, and is also referred to as the wavelength of the antenna system in free space (if the antenna is considered as a part of the antenna system). However, as the increase of the height H microstrip antenna becomes more sensitive to multipath reception. If the length L of the shielding plane 204 is in the range (1.0 to 1.5)λ, the height H greater than the threshold value H' (H'≈0,05)λ, causes an unwanted increase of the directivity diagram in the rear hemisphere,and deteriorating chart in the front hemisphere. The ratio D/U(θ=90°) deteriorates as close to 1.5 L+λ, and as decreases the threshold value H'. For applications in GPS, it is important to provide the desired ratio of the radiation up/down characteristic for angles close to θ=90°. To reduce the effects of multipath reception is a flat shielding plane is large in size L. the Increase in the height H of the radiating elements over the shielding plane is often necessary to extend the bandwidth of the antenna, and also to form a multi-tiered structure. Such geometric considerations apply to the dual band microstrip antenna shown in figure 3.

Frequency directivity microstrip antenna can be analyzed in accordance with the following mathematical model. In a first approximation, the resonant size of the radiating element is small enough so that the radiation can be considered as created by the slits formed by the edges of the radiating element and the shielding plane. This approximation is true, for example, for a wide directional antennas with a dielectric substrate having a high dielectric constant or dielectric substrate made of artificial dielectric structures with a high rate of deceleration. Wave Zam is allowing patterns can also be used when the dielectric medium is air (see further discussion below).

On figa reference rectangular coordinate system is defined by an axis 501 x axis 503 and y axis 505 z. Direction +y points in the plane of the drawing. The angle θ is measured from the axis 501x. In a two-dimensional approximation of the directional diagram of the antenna can be estimated by the model in the form of a filamentary magnetic current504 located at a height H above the shielding plane 502 with length L, through which the electric current is506. Vectordirected along the axis 503 y,and vectordirected along the axis 501 X.

From the analysis based on physical optics, electric field system can be expressed as follows:

where

- the electric field at an angleθ;

- electric field filamentary magnetic currentin free space;

- the electric field of the electric currentdescribing the effect of the shielding plane; and

- electric field filamentary electrical source at the pointx.

Current is assumed to be current, the induced sourceendless escape plane:

where

is the Hankel function of the second order of the second kind;

W=120π is the wave impedance of free space;

U is the voltage in the gap described filamentary magnetic current;

is the wave number;

x- the coordinate of the observation point; and

is the unit vector along the axis of thex:

The directional diagram of the antenna for this system is then expressed as follows:

For efficient radiation in the upward direction (+z) (see figv) of the electric field generated by sourcesand each current elementmust be the same phase.507509 specify a local normally located (up) vector at the points x=0, z=H and x=x, z=0, respectively. the phase of the induced electric current varies as(Here we used the asymptotic behavior of the Hankel.) Then the phase shift between polem> j_mand the field currentj_e(x)the distance from the origin iscan be approximated as:

From (E4) it is obvious that increasing the height H of the phase shift between the magnetic field current and field elements of the electric current increases. Therefore, the resulting amount is not optimal, and the ratio D/U worsens (increases) when θ=90°.

As x varies fromtofrom (E4) implies that starting with a certain length L will exist certain current value isthat can create an electric field opposite to the electric field created by. When these values of the antenna pattern in the front hemisphere is weakened and will be further deterioration of relations radiation down/up. At low H these values occur starting withand with the increase in the height H is diametrically opposite to the current region occur on a smaller length of the shielding plane.

Figure 6 presents the pattern for L/λ=1,2. The graphics displayed pattern [dB (power)] as a function of angle θ for testing the response to H/λ ranging from 0 to 0.2. The minimum pattern occurs when θ=90^aboutin the front hemisphere. 7 shows the corresponding plots for the relationship of radiation down/up. The ratio D/U is larger angle θ to 90°. On Fig shows graphs of the relationship of D/U(90) (θ=90°) as a function of the length of the shielding plane L for different heights H. the values of L and H are normalized to units of λ. Acceptable value of the ratio D/U(90) depends on the application and is the value specified by the user. In some applications, such as GPS, it is desirable to keep the ratio D/U(90) not less than -15 dB. For these applications, as can be seen from the graphs, H must be greater than 0,05λ.

On figa shows the reference rectangular coordinate system used in the following drawings broadband microstrip antenna systems corresponding to variants of the invention. Reference rectangular coordinate system, shown in perspective, is defined by an axis 1101 x axis 1103 y and axis z 1105. On FIGU-11E, 12, and 13, shown below, And is a view along direction +y and "B" is a view along the direction of-z.

On FIGU shown (view A) broadband microstrip antenna system, the corresponding variant of the invention, which reduces the sensitivity to multipath reception. Broadband microstrip Academy of Sciences of the military system includes the antenna unit 1112, having a cavity 1108. Here the antenna unit is also referred to as casing. Compared with the conventional microstrip antenna shown in figure 2, the shielding plane 1104 is no longer flat: it has a top surface 1104-T, surface 1104-S of the side wall and the bottom surface 1104-b Cavity 1108 facing the area, limited by the surface 1104-S of the side wall and the bottom surface 1104-B. note that the surface 1104-S of the side wall is not necessarily perpendicular. The slope depends on the application and defined by the user. Here the surface of the side wall is also referred to as the wall cavity. Here the lower surface 1104-B is also referred to as the bottom of the cavity. The height (also called depth) cavity 1108 equal to h.

A radiating element 1102A with length l_plocated in the transverse direction (see the discussion below) inside the cavity 1108. The height of the radiating element 1102A above the bottom surface 1104-B is equal to H. the Height of the radiating element 1102A above the upper surface 1104-T is equal to H₁. In the embodiment of the invention, the height H₁does not exceed 0,05λ. For this design the frequency characteristics are usually determined by the height H. the antenna pattern is determined by the height H₁and the length L of the shielding plane.

On figs presents B one broadband ICRI is a strip of the antenna system, the corresponding mean And shown in figv. The upper surface is designated as 1104-T-1; the surface of the side wall is designated as 1104-S-1; and the bottom surface marked 1104-In-1. On figs maximum surface 1104-T-1 shielding plane 1104 has a rectangular shape with a length L. In General, the top surface 1104-T-1 may be a two-dimensional shape, which is determined by the user for specific applications. For example, the shape can be square, rectangular, polygonal, circular or elliptical. In General, the length L represents the value characterizing the transverse size of the top surface 1104-T-1. Location and dimensions in the transverse direction relative to the x-y plane.

On figs the lower surface 1104-B-1 has a rectangular shape with length D. Usually lower surface 1104-B-1 may be a two-dimensional shape, which is determined by the user for specific applications. For example, the shape can be square, rectangular, polygonal, circular or elliptical. In General, the length D represents the value characterizing the transverse size of the top surface 1104-B-1.

On figs radiating element 1102A-1 has a rectangular shape with a length l_p. Usually radiating element A-1 may be a two-dimensional shape, which is determined by the user for specific applications. For example, fo the mA may be square, rectangular, polygonal, circular or elliptical. Typically, the length l_prepresents the value characterizing the transverse size of the radiating element A-1. Transverse between the radiating element 1102A-1 and surface 1104-S-1 of the side wall is defined by the user for a particular application.

On fig.11D presents a view B of the second broadband microstrip antenna system, the corresponding mean And figv. The upper surface is designated as 1104-T-2; the surface of the side wall is designated as 1104-S-2; the lower surface is marked 1104-B2. The top surface 1104-T-2 has a rectangular shape with a length L in the transverse direction. The lower surface 1104-B-2 has a circular shape with a size (diameter) D in the transverse direction. A radiating element 1102A-2 has a circular shape with a size (diameter) l_pin the transverse direction. Transverse between the radiating element 1102A-2 and surface 1104-S-2 side wall defined by the user for a particular application.

In accordance with figv during operation of the electromagnetic signals are fed to the radiating element 1102A through the Central conductor 1106 coaxial cable and cause of induced electric currents on sluchayem element 1102A and the shielding plane 1104. In a dielectric medium induced the floor is redazione currents. A radiating element, a shielding plane and dielectric environment all together emit electromagnetic waves in free space. The antenna device supports low height H₁the radiating element 1102A above the upper surface 1104-T shielding plane 1104, in order to reduce the sensitivity to multipath reception. At the same time, the height H of the radiating element 1102A above the bottom surface 1104-B shielding plane 1104 is large enough to provide the required bandwidth. Measurements have shown that when H₁approximately 0,05λ, radiation in the backward hemisphere is reduced and at the same time implemented a large band width.

Cavity 1108 can be filled with a dielectric medium such as air or a solid dielectric. Similarly, all of the space between the lower surface 1104-B and radiating element 1102A may be filled with a dielectric medium. Wave retarding structure (see below for further discussion) can also be entered on the lower surface 1104-B, a radiating element 1102A or on the lower surface 1104-B, and a radiating element 1102A together.

Measurements also showed that the frequency characteristics of the antenna is also affected by the diameter D of the cavity 1108. As discussed above, in General, D refers to the transverse size of the cavity 1108, is not necessarily to the diameter of the circle. The diameter D is chosen to balance the requirements of a sustainable bandwidth and the optimal relationship of radiation down/up. In the embodiment of the invention, the diameter D is determined by the algorithm:

where l_p- the length of the radiating element 1102A, C is a user - defined value in the range approximately from 0.1 to 0.2. Herewhere ε_effeffective dielectric constant of the dielectric environment. As a rule, l_p≤0,5λ. Note that the effective dielectric constant takes into account the electromagnetic characteristics of any wave-slowing structures that may be present.

On five shows a variant embodiment of the invention, in which a radiating element 1102B is horizontal with the top surface 1104-T shielding plane 1104; that is, H=h and H₁=0. In other embodiments the invention, the radiating element 1102B may be below the top surface 1104-T. In such cases, the height H₁can be considered as a negative value. As shown in figv and file, the receiver 1114 can be easily integrated in the antenna unit 1112, providing, thereby, a small overall size. The receiver 1114 is, for example, a receiver of global satellite navigation systems (GNSS)such as GPS or Galileo, GLONAS.

Broadband microstrip antenna system shown in figv and file suitable for radiation with linear polarization. Other embodiments of the invention can be made with the possibility of radiation with circular polarization. On figv and five radiating element 1102A and a radiating element 1102B respectively excited by a single Central conductor 1106. For radiation with circular polarization radiating elements can be powered by two Central conductors that excite two linearly polarized field orthogonal oriented in space.

Other embodiments of the invention can be made with the possibility of creating a dual-tiered antenna system. In the embodiment shown in Fig, the basic configuration is similar to configuration a single-band antenna system, shown in figv. Corresponding components have the same reference numbers. A radiating element 1102B, fed by a conductive probe 1106 is radiating element for the lower frequency band. A radiating element 1202, fed by a conductive probe 1206 is radiating element for the upper frequency band. The space between the lower surface 1104-B and radiating element 1102B may be filled with a dielectric medium such as air or a solid dielectric is Rick. Similarly, the space between the radiating element 1102B and radiating element 1202 may be filled with a dielectric medium. Conductive probe 1206 is electrically connected to radiating element 1102B, which also serves as a shielding plane for the radiating element 1202.

In order to achieve operation over a wide band of frequencies and the optimal relationship for radiation down/up in both frequency ranges, a radiating element 1102B and the radiating element 1202 is located inside the cavity 1108 in the transverse direction. In this embodiment, radiating element 1102B is horizontal with the top surface 1104-T shielding plane 1104 (like configuration file). In other embodiments, implementation of the radiating element 1102B raised above the upper surface 1104-T shielding plane 1104 (like configuration figv). The height of the radiating element 1202 above the upper surface 1104-T shielding plane 1104 is equal to H₂where H₂≈0,05λ. As discussed above, a radiating element 1102B and the radiating element 1202 may also be below the top surface 1104-T shielding plane 1104. The dimensions of the longline antenna system compact. One of the embodiments has a size of H₂=12 mm, h=22 mm, D=105 mm, and L=280 mm

Another variant implementation of the dual-band antenna system which we shown in Fig. The configuration is similar to that shown in Fig, except that the added slow wave structure. Wave slow-wave structures can be performed on the lower surface 1104-B, sluchayem element 1102B and sluchayem element 1202, individually or in any combination thereof. Wave-slowing structures can include, for example, a matrix of pins or ribs on the surfaces of the lower surface 1104-B, the radiating element 1102B and the radiating element 1202, as described in published patent application U.S. No. 2007/0205945 and European description of the invention to the patent EP 1684381 contained here by reference. Wave slow-wave structure may also contain elongated continuous structure or a series of localized structures along the perimeter of the bottom surface 1104-B, the radiating element 1102B and the radiating element 1202, as described in patent application U.S. No. 12/275761, which is included here by reference.

In the example shown in Fig, slow wave structure 1302 is performed on the lower surface 1104-In; slow wave structure 1304 is executed along the perimeter of the radiating element 1102B and are down towards the bottom surface 1104-B; slow wave structure 1308 performed along the perimeter of the radiating element 1102B and act in the direction of the radiating El the element 1202. In the example shown in Fig, no slow wave structures made on sluchayem element 1202 or along the perimeter of the radiating element 1202, but in other designs they can be.

The length L is typically 1-1,5λ, where λ is the wavelength in free space radiation emitted by the emitter 1202 (upper band). Here, the wavelength in free space radiation emitted by the emitter 1202, also referred to as the wavelength in free space of the upper frequency band. For applications such as GPS, the height H₂the radiating element 1202 above the upper surface 1104-T shielding plane 1104 is not more than 0,05λ. The height H₁the radiating element 1102B above the upper surface 1104-T shielding plane 1104 is selected so as to provide a corresponding lower frequency band. In the example on Fig H₁= 0 and is not shown. The diameter D can be selected according to the above equation (E5). For dual-band antenna l_pin (E5) refers to the length of the radiating element 1202. In one embodiment, the low band is 1160-1300 MHz and the upper frequency band is 1525-1610 MHz. Relevant dimensions: H₂=12 mm, h=22 mm, D=105 mm, L=280 mm, l₁=71 mm, l₂=54 mm, where l₁- the length of the radiating element 1102B, l₂- the length of the radiating ale the NTA 1202. As shown in Fig and Fig, the GNSS receiver may be integrated in the antenna unit 1112 to provide a compact overall dual-band antenna system.

Figure 9 and figure 10 presents a comparison of characteristics for conventional longline antenna with flat screen plane (as shown in figure 2) and characteristics of the longline antenna for shielding plane with the cavity (as shown in Fig). Figure 9 shows graphs of measured the radiation patterns at the frequency of 1575 MHz (induced upper radiating element). Graph 902 shows the results for the flat shielding plane, and graph 904 shows the results for the shielding plane cavity. On the chart 902 (flat screen plane) radiation pattern is reduced in the anterior hemisphere as θ greater than about 60 degrees. The graph 904 (shielding plane with the cavity) the radiation pattern, but essentially remains flat to 90 degrees. Figure 10 shows graphs of measured ratios radiation down/up. Comparison graph 1002 (flat screen plane) and the graph 1004 (shielding plane with a cavity) indicates improved (lower) the relationship of radiation up/down for shielding plane cavity. The improvement is particularly noticeable as θ approaches 90 degrees is.

The foregoing detailed description should in all respects be interpreted as illustrative and as an example, but not as limiting, and the scope of the invention disclosed here should be determined not from the detailed description and in the claims, interpreted in full, under the patent law. It should be understood that the illustrated and described here, the implementation is only an illustration of the principles of the present invention and that specialists in this field of technology can be implemented in various modifications without departing from the scope and essence of the invention. Specialists in the art can implement various other combinations of signs, without departing from the scope and essence of the invention.

1. Broadband microstrip antenna system, comprising:
ground plane that contains:
the first surface having a first lateral dimension; and
the cavity is filled with air, and the cavity contains
the second surface having a second transverse dimension; and
the surface of the side wall having a first height; and
a radiating element having a third lateral dimension, and a radiating element:
located transversely within the cavity;
has a second height from the first surface, the second height is greater than zero and not greater than 0,05λ, where λ is the wavelength of the free space for broadband microstrip antenna system; and
has a third height from the second surface; and
separated from the ground plane by air; and
conductor connected to the radiating element and configured to input electromagnetic signal radiating element.

2. Broadband microstrip antenna system according to claim 1, in which the first lateral dimension is approximately (1-1,5)λ, where λ is the wavelength in free space broadband microstrip antenna system.

3. Broadband microstrip antenna system according to claim 1, in which the second transverse dimension is determined in accordance with the algorithm:

where D second transverse dimension;
l_pthe third transverse size;
With a user-defined value in the range of from about 0.1 to 0.2; and
λ is the wavelength in free space for broadband microstrip antenna system.

4. Broadband microstrip antenna system according to claim 1, in which at less least one radiating element and the second surface are slow wave structure.

5. Broadband microstrip antenna system according to claim 4, in which the slow wave structure located along the perimeter of the at least one radiating element and the second surface.

6. Broadband microstrip antennas is I the system according to claim 5, in which the slow wave structure contain at least one elongated continuous structures and number of localized structures.

7. Dual-band broadband microstrip antenna system operating in the first frequency band and the second frequency band, in which a second frequency band higher than the first frequency band, comprising:
ground plane that contains
the first surface having a first lateral dimension; and
the cavity is filled with air, and the cavity contains
the second surface having a second transverse dimension; and
the surface of the side wall having a first height;
the first radiating element having a third lateral dimension, and the first radiating element:
made with the possibility of work in the first frequency band;
located in the transverse direction inside the cavity;
has a second height above the first surface, and
the second height is greater than zero and not greater than 0,05λ, where λ is the wavelength in free space for broadband microstrip antenna system;
has a third height above the second surface and
separated from the ground plane by air; and
the second radiating element having a fourth lateral dimension, and the second radiating element:
made with the second frequency band;
is transverse to the direction within the cavity;
has a fourth height above the first radiating element;
has one-fifth the height above the first surface and
separated from the first radiating element air;
a first conductor connected to the first radiating element and configured to input electromagnetic signal having a first bandwidth, the first radiating element; and
a second conductor connected to the second radiating element and configured to input electromagnetic signal having a second frequency band, the second radiating element.

8. Dual-band broadband microstrip antenna system according to claim 7, in which the first transverse dimension approximately equal to (1-1,5)λ, where λ is the wavelength in free space in the second frequency band.

9. Dual-band broadband microstrip antenna system according to claim 7, in which the second transverse dimension is determined in accordance with the algorithm:

where D second transverse dimension
l_p- fourth the transverse size;
C is a user - defined value in the range of from about 0.1 to 0.2; and
λ is the wavelength in free space of the second frequency band.

10. Dual-band broadband microstrip antenna system according to claim 7, in which at least one of the first islocalhost and the second surface are slow wave structure.

11. Dual-band broadband microstrip antenna system according to claim 7, in which along the perimeter of at least one of the first radiating element and the second surface are slow wave structure.

12. Dual-band broadband microstrip antenna system according to claim 11, in which the slow wave structure contain at least one elongated continuous structures and number of localized structures.

13. Dual-band broadband microstrip antenna system according to claim 7, in which at least one of the first radiating element and second radiating element are slow wave structure.

14. Dual-band broadband microstrip antenna system according to claim 7, in which along the perimeter of at least one of the first radiating element and second radiating element are slow wave structure.

15. Dual-band broadband microstrip antenna system 14, in which the slow wave structure contain at least one elongated continuous structures and number of localized structures.

16. Dual-band broadband microstrip antenna system according to claim 7, in which the first radiating element and second radiating element is designed with the ability to work in a dir is IU with linear polarization.

17. Dual-band broadband microstrip antenna system according to claim 7, in which the first radiating element and second radiating element is made with the possibility of operation with circular polarization.