JP2007306585A - Antenna and feed network for the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the size of the whole antennas and the loss amount of feed networks. <P>SOLUTION: A part of feed networks 1804, 1808 is disposed on the radiator portions of antennas 1304, 1308 and the remainder of the feed networks is disposed on feed portions to efficiently constitute areas. The trace of the feed network disposed on the radiator portion is disposed oppositely to the base portion of the radiator and the portion acts as a ground plane. The feed networks are mounted together with antennas of a type including single band and multiband helical antennas. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an antenna and a feed network for the antenna. More particularly, the present invention relates to a helical antenna with a feeding network provided in a region where a portion of the feeding network coincides with the radiator of the antenna.

  Current personal communication devices are widely used in many mobile and mobile applications. In traditional mobile applications, the desire to minimize the size of communication devices, such as mobile phones, has resulted in a moderate level of miniaturization. However, as portable hand-held applications have gained popularity, the demand for smaller devices has increased dramatically. Recent developments in processor technology, battery technology and communication technology have dramatically reduced the size and weight of portable devices over the past few years.

  One area where size reduction is desired is the antenna of the device. The size and weight of the antenna play an important role in downsizing the communication device. The overall size of the antenna affects the size of the device body. A small diameter and short antenna allows the overall size of the device to be reduced along with the body size.

  The size of the device is not the only factor that must be considered when designing an antenna for portable applications. Another factor to consider when designing an antenna is the effect of attenuation and / or jamming from the vicinity of the user's head on the antenna during normal operation. Yet another factor is the characteristics of the communication link, such as the desired radiation pattern, operating frequency, etc.

  An antenna that has found widespread use in satellite communication systems is a helical antenna. One reason for the popularity of helical antennas in satellite communication systems is the ability to create and receive circularly polarized waves used in such systems. In addition, a helical antenna can produce a radiation pattern that is approximately hemispherical, which is particularly suitable for applications in mobile satellite communication systems and satellite navigation systems.

  Conventional helical antennas are made by twisting the antenna radiator into a helical structure. A typical helical antenna is a four-wire helical antenna that utilizes four radiators spaced evenly around the core and is excited in quadrature (i.e., the radiator is one in one period). Excited by signals that differ in phase by / 4 or 90 °). The length of the radiator is typically an integer multiple of a quarter wavelength of the operating frequency of the communication device. The radiation pattern is typically adjusted by changing the pitch of the radiator, the length of the radiator (an integer multiple of a quarter wavelength), and the diameter of the core.

  Conventional helical antennas can be made using wire or strip technology. In strip technology, the antenna radiator is etched or deposited on a thin flexible substrate. The radiators are parallel to each other but are positioned at an obtuse angle with respect to the sides (or edges) of the substrate. Thereafter, the substrate is formed or rolled into a cylindrical, conical, or other suitable shape so that the strip radiators form a spiral.

  However, this conventional helical antenna has a radiator length that is an integer multiple of a quarter wavelength of the desired resonant frequency, so that the overall length of the antenna is longer than desired for some portable or mobile applications. It has the feature that it ends up.

  In addition, dual band antennas are desirable in applications where transmission and reception occur at different frequencies. However, dual band antennas are often only available at lower than desired settings. For example, one way in which dual-band antennas can be manufactured is to overlap the ends of two single-band 4-wire helical antennas so that they form a column. However, the drawback of this solution is that such an antenna would be longer than would be desirable for a portable or hand held type application.

  Another technique that provides dual-band performance has been to utilize two separate single-band antennas. However, for a hand-held type device, the two antennas must be placed close to each other. Two single-band antennas placed close together on a portable or hand-held type device will cause coupling between the two antennas, leading to undesirable interference with degraded performance.

  In one aspect, the invention comprises a substrate; a radiator portion comprising a plurality of radiators disposed on the substrate, the substrate being shaped such that the radiator is configured in a spiral shape; A feed portion adjacent to and comprising a substrate; a first set of one or more traces disposed on the substrate of the feed portion; and a second set disposed on the substrate of the radiator portion A helical antenna comprising a feeding network comprising one or more traces.

  In another aspect, the invention comprises a first set of one or more traces disposed in a feed portion of an antenna and a second set of one or more traces disposed in a radiator portion of the antenna. Provide a network.

  In a further aspect, the invention provides a first feeding network disposed on a first side of a substrate of a first feeding portion of a first antenna, and a second feeding side of the substrate, the feeding network being disposed on a second side of the substrate. A first ground plane opposite to the first antenna portion comprising a first set of one or more radiators disposed on the substrate and extending from the feeder network; disposed on the substrate of a second feeder portion A second power supply network, a second ground plane disposed on the substrate opposite the power supply network, and a second set of one or more radiators disposed on the substrate and extending from the power supply network And a path for current flowing from the radiator of the second antenna along the axis of the second antenna, thereby being radiated in a direction perpendicular to the axis Ru A dual-band helical antenna comprising means for increasing energy, wherein the first feed network is a first set of one or more traces disposed in the first feed portion of the antenna; And a second set of one or more traces disposed in the radiator portion of the antenna portion, wherein the second feed network is disposed in the second feed portion. And a fourth set of one or more traces disposed in the radiator portion of the second antenna portion.

  In a further aspect, the invention provides that two sets of interdigitated tracks are provided on a common substrate formed on a curved surface, the tracks follow each substantially helical path, and a set of feed networks. Provide an antenna that matches part of the track.

  The present invention is embodied in a new and improved feed network for an antenna that includes a radiator portion and a feed portion. The feed network is configured such that a portion of the feed network is disposed in the radiator portion of the antenna and the remaining portion of the feed network is disposed in the feed portion. Since a part of the feeding network is arranged in the radiator part, the rest of the feeding network requires little area for the feeding part. As a result, the feeding portion of the antenna can be made smaller than that of an antenna having a conventional feeding network. Since this configuration requires only a small area in the power feeding portion, it can be said that the power feeding network is area efficient.

  In a preferred embodiment, a feed network trace placed in the radiator section is placed opposite the base section of the radiator. Thus, the basic part of the radiator acts as a ground plane for this part of the feed network.

  The feed network can be implemented with many different types of antennas in varying configurations, including single-band and multi-band helical antennas.

  One advantage of the invention is that the overall size of the antenna and the amount of feed loss is reduced compared to an antenna having a conventional feed network.

  In one embodiment, the feed network is implemented with a dual-band helical antenna having two sets of one or more helically wound radiators. The radiator is wrapped or wrapped so that the antenna is cylindrical, conical, or other suitable shape to obtain an optimized or otherwise desired radiation pattern. According to this implementation, a set of radiators is provided for operation at the first frequency and a second set is preferably provided for operation at a second frequency different from the first frequency. Each set of radiators has an associated feed network to provide signals and drive the radiators. Thus, a dual band antenna can be described as having two single band antennas, each having a radiator portion and a feed portion.

  A tab can be provided to provide a signal to the first single band antenna. The tab extends from the feeding portion of the first single band antenna. When the antenna is formed in a cylindrical shape or other suitable shape, the tab is aligned with the antenna axis. More particularly, in a preferred embodiment, the tabs extend radially inward to provide a centrally located feed structure. Thus, the tab and the feed line do not interfere with the signal pattern of the second single band antenna.

  The features, objects, and advantages of the present invention will become apparent from the following detailed description of the embodiments of the invention, taken in conjunction with the drawings. In the drawings, like reference characters identify corresponding corresponding elements throughout the drawings. In addition, the leftmost digit of a reference number identifies the drawing in which the reference number first appears.

I. Overview and Discussion of the Invention The present invention is directed to an efficient area feed network for antennas. A part of the feeding network is provided in the radiator part of the antenna. This reduces the area required for the feeding portion of the antenna.

II. Exemplary Environment In a broad sense, the invention can be implemented in any system that can utilize helical antenna technology. An example of such an environment is a communication system in which a user having a landline, mobile and / or mobile phone communicates with others through a satellite communication link. In this exemplary environment, it is necessary for the telephone to have an antenna tuned to the frequency of the satellite communications link.

  The present invention will be described with respect to this exemplary environment. These descriptions are provided for convenience only and are not intended to limit the invention to this exemplary environment. Indeed, after reading the following description, it will become apparent to a person skilled in the art how to implement the invention in alternative environments.

III. Conventional Helical Antenna Before describing embodiments of the invention in detail, it is useful to describe the radiator portion of a conventional helical antenna. In particular, this section of the specification describes the radiator portion of a conventional 4-wire helical antenna. 1A and 1B are views showing a radiator portion 100 of a conventional 4-wire helical antenna having a wire shape and a strip shape, respectively. The radiator portion 100 shown in FIGS. 1A and 1B is of a four-wire helical antenna, meaning that it has four radiators 104 operating in quadrature. As shown in FIGS. 1A and 1B, radiator 104 is wound to provide circular polarization.

  2A and 2B are diagrams showing a planar display of a radiator portion of a conventional 4-wire helical antenna. In other words, FIGS. 2A and 2B show a radiator that would appear if the antenna column was “unfolded” on a flat surface. FIG. 2A is a diagram showing an open circuit or open terminated 4-wire helical antenna at the far end. For such a configuration, the resonant length l of radiator 208 is an odd integer multiple of a quarter wavelength of the desired resonant frequency.

  FIG. 2B is a diagram showing a 4-wire helical antenna that is short-circuited or electrically connected at the far end. In this case, the resonance length l of the radiator 208 is an even integer multiple of a quarter wavelength of the desired resonance frequency. Note that in both cases, the resonance length l described above is an approximation, since some adjustment is usually required to compensate for the non-ideal short open termination.

  FIG. 3 shows a plan view of the radiator portion of a 4-wire helical antenna 300 including a radiator 208 having a length l = λ / 2, where λ is the wavelength of the desired resonant frequency of the antenna. FIG. Curve 304 represents the relative magnitude of the current for the signal on radiator 208 that resonates at a frequency of f = ν / λ, where ν is the signal speed in the medium.

  A mounting example of a four-wire helical antenna mounted using printed circuit board technology (strip antenna) will be described in detail with reference to FIGS. The strip 4-wire helical antenna has strip radiators 104A-104D etched on a dielectric substrate 406. The substrate is a thin, flexible material that is rolled into a cylindrical, conical or other suitable shape such that the radiators 104A-104D are spirally wound about the central axis of the column.

  4-5 illustrate the components used to create the 4-wire helical antenna 100. FIG. 4a and 4b depict views of the distal surface 400 and proximal surface 500 of the substrate 406, respectively. The antenna 100 includes a radiator portion 404 and a feed portion 408.

  In the embodiment described and illustrated herein, the antenna is described as being formed by forming the substrate into a cylindrical shape and being on the outer surface of the column with the proximal surface formed. In another embodiment, the substrate is formed in a cylindrical shape and the distal surface is on the outer surface of the post.

  In one embodiment, dielectric substrate 100 is a thin flexible layer of polytetrafluoroethalene (PTEE), PTEE / glass composite, or other dielectric material. In one embodiment, the substrate 406 is about 0.005 inches or 0.13 mm thick, although other thicknesses can be chosen. Signal traces and ground traces are provided using copper. In another embodiment, other conductive materials may be chosen instead of copper, taking into account costs, environmental issues and other factors.

  In the embodiment shown in FIG. 4b, the feed network 508 is etched on the feed portion 408 to provide quadrature signals (ie, 0 °, 90 °, 180 ° and 270 ° signals provided to the radiators 104A-104D). )I will provide a. The feeding portion 408 of the distal surface 400 provides a ground plane 412 for the feeding circuit 508. The signal trace for the feed circuit 508 is etched into the proximal surface 500 of the feed portion 408.

  For illustrative purposes, the radiator portion 404 has a first end 432 adjacent to the feed portion 408 and a second end 434 (the opposite ends of the radiator portion 404). Depending on the antenna embodiment implemented, radiators 104A-104D can be etched into distal surface 400 of radiator portion 404. FIG. The length of radiators 104A-104D extending from first end 432 toward second end 434 is approximately an integer multiple of a quarter wavelength of the desired resonant frequency.

  In such embodiments where radiators 104A-104D are integer multiples of λ / 2, radiators 104A-104D are electrically connected (ie, shorted or shorted) to each other at second end 434. This connection can be made by a wire across the second end 434 that forms a ring 604 around the circumference of the antenna when the substrate is formed into a pillar. FIG. 5 is a perspective view of an etched substrate of a strip helical antenna having a short ring 604 at the second end 434.

  One conventional four-wire helical antenna is described in US Pat. No. 5,198,831 (referred to as the '831 patent) by Burrell et al., Which is incorporated herein by reference. The antenna described in the '831 patent is a printed circuit board antenna having a radiator etched or otherwise deposited on a dielectric substrate. The substrate is formed into a pillar, creating a helical configuration of radiators.

  Another conventional 4-wire helical antenna is disclosed in Terret et al. US Pat. No. 5,255,005 (referred to as the '005 patent), which is incorporated herein by reference. The antenna described in the '005 patent is a four-wire helical antenna formed by two bifilar (two-wire) spirals positioned orthogonally and excited in quadrature. The disclosed antenna has a second four-wire helix, which is coaxially and electromagnetically coupled with the first helix to improve the antenna passband.

  Yet another conventional 4-wire helical antenna is disclosed in US Pat. No. 5,349,365 (referred to as the '365 patent) by Ow et al., Which is incorporated herein by reference. The antenna described in the '365 patent is a four-wire helical antenna designed in the wire shape described with reference to FIG. 1A.

IV. In order to shorten the length of the radiator portion 100 of the coupled multi-segment helical antenna antenna, one form of helical antenna utilizes a coupled multi-segment radiator, which is necessary for helical antennas of equal resonant length. Enables resonance at a predetermined frequency with a shorter length than the wax.

  6A and 6B are diagrams illustrating a planar view of an example of an embodiment of a coupled segment helical antenna. FIG. 6A illustrates a coupled multi-segment radiator 706 that terminates in an open circuit according to one single wire embodiment. Such open circuit terminated antennas can be used in single wire, two wire, four wire, or other x-ray implementations.

  The embodiment shown in FIG. 6A includes one radiator 706. Radiator 706 comprises a set of radiator segments. This set comprises two end segments 708, 710 and p intermediate segments 712, where p = 0, 1, 2, 3,. . . (The case of p = 3 is shown). The intermediate segment is arbitrary (ie, p may be equal to zero). The end segments 708, 710 are physically separated from each other but are electromagnetically coupled. Intermediate segment 712 is positioned between end segments 708, 710 and provides electromagnetic coupling between end segments 708, 710.

In the open-terminated embodiment, the length l _s1 of segment 708 is an odd integer multiple of a quarter wavelength of the desired resonant frequency. The length l _s2 of the segment 710 is an integer multiple of ½ wavelength of the desired resonance frequency. The length _{l sp} of each of the p intermediate segments 712 is an integer multiple of the half wavelength of the desired resonant frequency. In the illustrated embodiment, there are three intermediate segments 712 (ie, p = 3).

  FIG. 6B illustrates a helical antenna radiator 706 when terminated with a short 722. This short circuit implementation is not suitable for single wire antennas, but can be used for 2-wire, 4-wire or other x-ray antennas. As in the open circuit embodiment, radiator 706 comprises a set of radiator segments. This set comprises two end segments 708, 710 and p intermediate segments 712, where p = 0, 1, 2, 3,. . . (The case of p = 3 is shown). The intermediate segment is arbitrary (ie, p may be equal to zero). The end segments 708, 710 are physically separated from each other but are electromagnetically coupled. Intermediate segment 712 is positioned between end segments 708, 710 and provides electromagnetic coupling between end segments 708, 710.

The shorted embodiment, the length l _s1 of segment 708 is an odd integer multiple of a quarter wavelength of the desired resonant frequency. The length l _s2 of the segment 710 is an odd integer multiple of a quarter wavelength of the desired resonance frequency. The length _{l sp} of each of the p intermediate segments 712 is an integer multiple of the half wavelength of the desired resonant frequency. In the illustrated embodiment, there are three intermediate segments 712 (ie, p = 3).

  FIGS. 7A and 7B are diagrams illustrating a radiator portion 800 of a coupled multi-segment 4-wire helical antenna according to one embodiment of the invention. FIGS. 7A and 7B show one implementation of the antenna shown in FIG. 6B, where p = zero (ie, there is no intermediate segment 712) and the lengths of segments 708 and 710 are 1/4 wavelength. .

  The radiator portion 800 shown in FIG. 7A is a planar representation of a four-wire helical antenna and has four coupled radiators 804. Each coupled radiator 804 in the coupled antenna actually has two radiator segments 708, 710 positioned in close proximity to each other, and the energy of the radiator segment 708 is coupled to the other radiator segment 710. The

  More particularly, according to one embodiment, the radiator portion 800 can be described as having two portions 820, 824. Portion 820 has a plurality of radiator segments 708 that extend from first end 832 of radiator portion 800 toward second end 834 of radiator portion 800. Portion 824 has a plurality of radiator segments 710 extending from second end 834 of radiator portion 800 toward first end 832. Towards the central region of the radiator portion 800, a portion of each segment 708 is proximate to an adjacent segment 710, and energy from one segment is coupled to the adjacent segment in the proximate portion. This is referred to as an overlapping portion in this specification.

In the preferred embodiment, each segment 708, 710 is approximately l ₁ = l ₂ = λ _{/ 4} long. The total length of one radiator comprising two segments 708, ₇₁₀ is defined as l _tot . The amount by which one segment 708 overlaps another segment 710 is defined as δ = l ₁ + l ₂ −l _tot .

For the resonance frequency f = ν / λ, the total length of the radiator l _tot is shorter than the length of ½ wavelength of λ _{/ 2} . In other words, as a result of the coupling, a radiator comprising a pair of coupling segments 708, 710 resonates at a frequency f = ν / λ, even though the total length of the radiator is shorter than λ _{/ 2} . Accordingly, the radiator portion 800 of the ½ wavelength coupled multi-segment 4-wire helical antenna is shorter than the radiator portion of the conventional ½ wavelength 4-wire helical antenna 800 for a predetermined frequency f.

To clearly illustrate the size reduction obtained by using the combined configuration, compare the radiator portion 800 illustrated in FIG. 7 to that illustrated in FIG. For a given frequency f = ν / λ, the length l of the radiator portion 300 of the conventional antenna is λ _{/ 2} , while the length l _tot of the radiator portion 800 of the coupled radiator segment antenna is λ. Shorter than _{/ 2} .

As described above, in one embodiment, the segments 708, 710 are of length l ₁ = l ₂ = λ _{/ 4} . The length of each segment can be varied so that l ₁ does not necessarily equal l ₂ and they are not equal to λ _{/ 4} . The actual resonant frequency of each radiator is a function of the length of radiator segments 708, 710, the separation distance between radiator segments 708 and 710, and the amount that segments 708 and 710 overlap each other.

Note that changing the length of one segment 708 relative to the other segment 710 can be used to adjust the bandwidth of the antenna. For example, lambda _{/ 4} As is slightly larger and longer l _1, by shortening the l ₂ to be slightly shorter than lambda _{/ 4,} can increase the bandwidth of the antenna.

  FIG. 7B illustrates an actual helical configuration of a coupled multi-segment 4-wire helical antenna according to one embodiment of the invention. This illustrates how each radiator comprises two segments 708, 710 in one embodiment. The segment 708 extends helically from the first end 832 of the radiator portion toward the second end 834 of the radiator portion. The segment 710 extends helically from the second end 834 of the radiator portion toward the first end 832 of the radiator portion. Further, FIG. 7B shows that portions of segments 708 and 710 overlap so that they are electromagnetically coupled to each other.

FIG. 8A shows the separation s and the overlap δ between radiator segments 708 and 710. Separation s is chosen so that a sufficient amount of energy is coupled between radiator segments 708 and 710 so that they can function as one radiator with an effective electrical length of approximately λ _{/ 2} and an integer multiple thereof. .

Spacing of the radiator segments 708, 710 closer than this optimal spacing creates a large coupling between the segments 708, 710. As a result, for a given frequency f, the length of segments 708, 710 must be increased to allow resonance at the same frequency f. This can be illustrated by the extreme case of physically connected (ie, s = 0) segments 708, 710. In this extreme case, the total length of the segments 708, 710 must be equal to λ _{/ 2} for the antenna to resonate. In this extreme case, the antenna is no longer actually “coupled” according to the use of the terminology herein, and the resulting configuration is actually that of a conventional helical antenna as shown in FIG. is there.

  Similarly, increasing the amount of overlapping portion δ of segments 708, 710 increases binding. Thus, as the overlap portion δ increases, the lengths of the segments 708 and 710 also increase.

For a qualitative understanding of the optimal overlap and spacing for segments 708, 710, refer to FIG. 8B. FIG. 8B represents the magnitude of the current on each segment 708, 710. Current strength indicators 911, 928 indicate that each segment ideally resonates at λ _{/ 4} and has a maximum signal strength at the outer end and a minimum signal strength at the inner end.

In order to optimize the antenna profile for the combined radiator segment antennas, we use modeling software to determine the exact segment lengths l ₁ , l ₂ among other parameters. The overlapping portion δ and the spacing s were determined. Such a software package is an antenna optimizer (AO) software package. AO is based on the method of moments electromagnetic antenna-modeling. AO Antenna Optimizer, version 6.35, copyright 1994, was written by and available from Brian Beezley, San Diego, California.

  Note that there are advantages gained by using a combined configuration, as described above with reference to FIGS. 7A and 7B. In conventional antennas and coupled radiator segment antennas, the current is concentrated at the end of the radiator. According to array element theory, this can be used in favor of a coupled radiator segment antenna in a particular application.

For illustration purposes, FIG. 9A is a diagram illustrating two point sources A and B, where source A has a magnitude equal to that of source B, but radiates a signal that is 90 degrees out of phase. ( ^{Assuming an} e ^jwt convention). If the sources A and B are separated by a distance of λ _{/ 4} , the signal adds phase in the direction moving from A to B and adds away from the phase in the direction from B to A. As a result, very little radiation is emitted in the direction from B to A. The typical representative field pattern shown in FIG. 9B illustrates this point.

  Thus, when sources A and B are oriented so that the direction from A to B is upward, away from the ground, and the direction from B to A is toward the ground, the antenna is optimal for most applications. It becomes. This is because the user rarely desires an antenna that indicates the signal strength toward the ground. This configuration is particularly useful for satellite communications where it is desired that the majority of the signal strength be directed away from the ground.

The point source antenna designed in FIG. 9A is difficult to achieve using a conventional half-wave helical antenna. Consider the radiator portion of the antenna shown in FIG. The concentration of current intensity at both ends of radiator 208 approximates a point source. When the radiator is twisted into a helical profile, one end of the 90 ° radiator is positioned in alignment with the other end of the 0 ° radiator. Thus, it approximates two point sources in a straight line. However, these approximate point sources are separated by approximately λ _{/ 2} for the desired λ _{/ 4} configuration illustrated in FIG. 9A.

However, it should be noted that the coupled radiator segment antenna embodying the invention provides an implementation in which the approximated point sources are spaced apart at a distance close to λ _{/ 4} . Thus, the combined radiator segment antenna allows the user to take advantage of the directional characteristics of the antenna illustrated in FIG. 9A.

  The radiator segments 708, 710 illustrated in FIG. 7 indicate that each segment 708 is very close to its associated segment 710, but each pair of segments 708, 710 is relatively spaced from an adjacent pair of segments. Show. In one alternative embodiment, each segment 710 is equidistant from segment 708 on either side. This embodiment is shown in FIG.

Next, in FIG. 10, each segment is substantially equidistant from each pair of adjacent segments. For example, segment 708B is equidistant from segments 710A and 710B. That is, s ₁ = s ₂ . Similarly, segment 710A is equidistant from segments 708A and 708B.

  This embodiment is counterintuitive in that it appears as if an undesirable bond exists. In other words, a segment corresponding to one phase will couple not only to an appropriate segment of the same phase, but also to an adjacent segment of the shifted phase. For example, segment 708B, a 90 ° segment would couple to segments 710A (0 ° segment) and 710B (90 ° segment). Such coupling is not a problem because the radiation from the upper segment 710 can be considered as two separate modes. One mode results from coupling to the left adjacent segment and the other mode results from coupling to the right adjacent segment. However, both of these modes are adjusted in phase so that they provide radiation in the same direction. This double bond is therefore not detrimental to the operation of the coupled multi-segment antenna.

  FIG. 11 is a diagram illustrating an example implementation of a combined radiator segment antenna. In FIG. 11, the antenna includes a radiator portion 1202 and a feeding portion 1206. The radiator portion includes segments 708, 710. The dimensions provided in FIG. 11 show the contribution of segments 708, 710 to the total length of radiator portion 1202 and the amount of overlap portion δ.

The length of the segment in the direction parallel to the axis of the column is shown as l ₁ sin α for segment 708 and l ₂ sin α for segment 710, where α is that of segments 708, 710. It is an inner corner.

  As illustrated in FIGS. 7A and 8A, the overlapping portion of the segment is indicated by the reference character δ. The amount of overlap in the direction parallel to the axis of the antenna is given by δ sin α, as shown in FIG.

Segments 708, 710 are separated by spacing s, which can vary as described above. The distance between the ends of segments 708 and 710 and the end of radiator portion 1202 is defined as a gap and is illustrated by reference characters γ ₁ and γ ₂ respectively. The gaps γ ₁ and γ ₂ may be equal to each other, but need not be equal. Again, as described above, the length of segment 708 can vary relative to the length of segment 710.

The offset amount from one end of the segment 710 to the next segment is indicated by the reference character ω ₀ . The separation between adjacent segments 710 is indicated by the reference character ω _s and is determined by the diameter of the helix.

  Feed portion 1206 includes a suitable feed network to provide a quadrature signal to radiator segment 708. Feed networks are known to those skilled in the art and are therefore not described in detail here.

In the embodiment shown in FIG. 11, the segments 708 are fed at each feed point located at a distance from the feed network chosen to optimize impedance matching along each segment 708. In the embodiment shown in FIG. 11, this distance is illustrated by the reference character δ _feed .

  Note that continuous line 1224 illustrates the boundary for the ground portion of the distal surface of the substrate. A grounded portion opposite the distal surface segment 708 extends to the feed point. A thin portion of segment 708 is on the proximal surface. At the feed point, the thickness of the segment 708 on the proximal surface increases.

  Next, dimensions are provided for an example of a coupled radiator segment 4-wire helical antenna suitable for operation in the L band at approximately 1.6 GHz. Note that this is for example purposes only, and other dimensions are possible for operation in the L band. In addition, other dimensions are possible for operation in other frequency bands as well.

The overall length of radiator portion 1202 in the L-band embodiment is 2.30 inches (58.4 mm). In this embodiment, the pitch angle α is 73 °. At this angle α, the length l ₁ sin α of the segment 708 for this embodiment is 1.73 inches (43.9 mm). In the illustrated embodiment, the length of segment 710 is equal to the length of segment 708.

In one example, segment 710 is positioned substantially equidistant from an adjacent pair of segments 708. In one implementation of this embodiment where segment 710 is equidistant from adjacent segment 708, spacing s ₁ = s ₂ = 0.086 inches. Other spacings are possible, for example, spacing s of segments 710 that are 0.070 inches (1.8 mm) from adjacent segments 708.

  The width τ of the radiator segments 708, 710 is 0.11 inches (2.8 mm) in this embodiment. Other widths are possible.

The L-band example is characterized by a symmetric gap γ ₁ = γ ₂ = 0.57 inch (14.5 mm). If the gap γ is symmetric with respect to both ends of the radiator portion 1202 (ie, γ ₁ = γ ₂ ), the radiators 708, 710 are 1.16 inches (29.5 mm) (1.73-0.57). Inch) overlap portion δsinα.

The segment offset ω _o is 0.53 inches and the segment separation ω _s is 0.393 inches (10.0 mm). The diameter of the antenna is 4ω _s / π.

In one embodiment, this is chosen such that the distance δ _feed from the feed point to the feed network is δ _feed = 1.57 inches (39.9 mm). Other feed points can also be selected to optimize impedance matching.

  The example embodiment described above is designed for use in connection with a 0.032 inch thick polycarbonate radome that surrounds the helical antenna and contacts the radiator. It will be apparent to those skilled in the art how a radome or other structure affects the wavelength of the desired frequency.

In the example of the embodiment just described, the total length of the radiator portion of the L-band antenna is reduced from the total length of the conventional half-wavelength L-band antenna. For a conventional half-wavelength L-band antenna, the length of the radiator portion is about 3.2 inches (ie, λ _{/ 2} (sin α)), and α is a segment 708, 710 relative to the horizontal position. ), Or (81.3 mm). For the example embodiment described above, the overall length of the radiator portion is 2.3 inches (58.42 mm). This represents a substantial savings in the size of conventional antennas.

V. Having described several embodiments of stacked dual band helical antenna single band helical antennas, a dual band embodying the present invention will now be described. The present invention is directed to a dual-band helical antenna that can resonate at two different operating frequencies. The two helical antennas are stacked end to end, one antenna resonates at the first frequency, and the other antenna resonates at the second frequency. Each antenna has a radiator portion that includes one or more spirally wound radiators. Each antenna has a feed portion with a feed network and a ground plane. The two antennas are stacked so that the ground plane of one antenna is used as a shorting ring across the distal end of the radiator of the other antenna.

  FIG. 12 is a diagram illustrating a planar view of the distal surface 400 and proximal surface 500 of a dual-band helical antenna according to one embodiment of the invention. The dual-band helical antenna includes two single-band helical antennas, with the helical antenna 1304 operating at the first resonance frequency and the helical antenna 1308 operating at the second resonance frequency.

  In the embodiment shown in FIG. 12, feed network 508, radiators 104 </ b> A- 104 </ b> D, and first antenna 1304 are disposed on the proximal surface 500 of first antenna 1304. Also disposed on the proximal surface 500 is a ground plane 412 for the feed network 508 of the second antenna 1308. Disposed on the distal surface 400 is a ground plane 412 for the feed portion of the first antenna 1304 along with the feed network 508 and the radiators 104A-104D of the second antenna 1308.

  As described above with reference to FIGS. 2A and 2B, when the resonant length l of radiators 104A-104D is an even integer multiple of a quarter wavelength of the desired resonant frequency, the distal ends of radiators 104A-104D are Shorted. As shown in FIG. 12, this short circuit is achieved using the ground plane 412 of the first antenna 1304. As a result of this configuration, no additional shorting ring need be added to the end of radiators 104A-104D.

  In the embodiment shown in FIG. 12, since the ends of radiators 104A-104D are open circuits, the first antenna 1304 is shown as resonating at an odd integer multiple of a quarter wavelength of the desired resonant frequency. Note that In another embodiment, the length of these radiators 104A-104D is changed to be an even integer multiple of a quarter wavelength of the desired resonant frequency while a shorting ring (not shown) is connected to the first antenna. 1304 could be added to the far end of these radiators 104A-104D.

The dual-band antenna radiators 104A-104D described with reference to FIG. 12 are illustrated as being fed at a first end near the feed network 508. It is known that the feed point of the radiators 104A-104D of the helical antenna is located at any point along the length of the radiators 104A-104D, and such positioning is determined primarily based on impedance matching considerations. Is done. FIG. 13 is a diagram illustrating an embodiment of a dual band helical antenna in which the feed points of radiators 104A-104D are positioned at a predetermined distance from feed network 508. In FIG. In particular, in the embodiment shown in FIG. 13, the feed point A of the first antenna 1304 is located at a distance l _FEED1 from the feed network 508, and the feed point B of the second antenna 1308 is located at a distance l _FEED2 from the feed network 508. .

  In this embodiment, radiators 104A-104D have ground traces 1436 on the first surface of substrate 406, ground traces 1438 opposite said ground trace 1436 on the second surface of substrate 406, and on the second surface of substrate 406. Radiator traces 1440.

  As in the embodiment shown in FIG. 12, in this embodiment, the second antenna 1308 has a radiator that resonates at an even integer multiple of a quarter wavelength of the desired resonant frequency. Ground plane 412 acts as a shorting ring for radiators 104A-104D and second antenna 1308.

  To reduce the overall length of the stacked antennas, the edge coupling technique described above can be utilized. In such an embodiment, the radiators 104A-104D of the first antenna 1304 and / or the second antenna 1308, as illustrated in FIGS. 12 and 13, may be combined with edges, for example, as shown in FIG. Is replaced.

  One challenge to provide a dual band antenna as illustrated in FIGS. 12 and 13 is to power the first antenna 1304. For this purpose, the first antenna 1034 is fed by a tab extending from the lower region of the feeding portion of the first antenna 1304.

  FIG. 14 is a diagram illustrating such a tab used to power the first antenna 1304. In FIG. 14, the tab 1504 extends from the side of the feeding portion of the first antenna 1304 on the substrate 406. In the embodiment illustrated in FIG. 14, the tab 1504 is generally “L” shaped and extends horizontally from the feed portion of the first antenna 1304 at a predetermined distance and then in the direction of the feed portion of the second antenna 1308. It is bent at an angle in the axial direction through the center. Although 1504 is illustrated as being shaped at a right angle, other angles may be used as it may be a curve of various radii.

  Ideally, when the substrate 406 is rolled into a pillar or other suitable shape to form a helical antenna, the axial component 1524 of the tab 1504 is substantially along the axis of the dual-band helical antenna. Having the axial component 1524 of the tab 1504 coincident with the axis of the helical antenna minimizes the effect of this member on the antenna radiation pattern. As shown in FIG. 14, in a preferred embodiment, the tab 1504 extends from the feed portion of the first antenna 1304 in a vertical position as far as possible from the first antenna 1304. This is to minimize the influence of the tab 1504 on the radiation pattern of the first antenna 1304. Since the second antenna 1308 is a coupling segment half wavelength antenna and the ends of the radiators 104A to 104D of the second antenna 1308 are short-circuited by the ground plane 412 of the first antenna 1304, the tab 1504 is connected to the second antenna 1308. Has the least effect on the radiation pattern.

Preferably, the length l _gp of the feeding portion 1206 of the first antenna 1304 can be determined in consideration of two factors at an appropriate operating frequency. First, it is desirable to minimize the amount of current flowing from the radiator of the first antenna 1304 to the second antenna 1308 and vice versa. In other words, it is desirable to achieve isolation between the two antennas. This can be accomplished by ensuring that the current is long enough to prevent current from extending from one set of radiators to the other at the frequency in question.

  Another challenge is the goal of preventing current from radiators 104A-D of first antenna 1304 from reaching tab 1504. The current from the first antenna 1304 is attenuated as it moves across the feed portion of the first antenna 1304 toward the tab 1504. Tab 1504 creates an asymmetric break in these currents. Therefore, it is desirable to minimize the amount of current reaching tab 1504 to a practical extent.

After reading this description, it will be clear to those skilled in the art how to implement a feed portion 1206 of appropriate length l _gp based on the material used, the frequency in question, the expected antenna power level, and other known factors. It will be clear. This decision may entail a trade-off between size and performance.

  Note that in this embodiment, the effects of tab 1504 are not at all present. Since the tab 1504 is in the vicinity of the radiator of the second antenna 1308, some of the current from the second antenna 1308 is coupled to the tab 1504 and thus along the axis of the antenna. This current affects the radiation of the second antenna 1308 and causes increased radiation to the sides of the antenna. For applications where the antenna is mounted vertically, this increases radiation in the horizontal direction and decreases radiation in the vertical direction. As a result, this application is suitable for satellite communication systems where low earth orbits are used to relay communications between communication devices.

  This effect is illustrated in FIG. 9C, where the circular polarization radiation pattern 1010 displays a typical radiation pattern for a conventional helical antenna, and the radiation pattern 1020 represents the radiation pattern for the second antenna 1308. it's shown. As shown in FIG. 9C, the pattern 1020 is “flat” and “wider” than the conventional pattern 1010.

  To allow signal coupling to the first antenna 1304, the tab 1504 is suitable for making a connection between a connector such as a crimp, or a soldered connector or feeder cable and a signal trace on the tab 1504. Includes other connectors. Various types of cables or wires can be used to connect the transceiver RF circuit to the antenna at tab 1504. Preferably, a low-loss flexible or semi-rigid cable is used. Of course, as is known in the antenna industry, it is desirable to match the impedance of the feed input to the impedance of the interface cable in order to maximize power transfer to the antenna. However, if the input transition is poor, the radiation patterns will still be symmetric, but their gain will be reduced by a corresponding amount of reflection loss. In addition to low insertion loss, it is important that the connector provide a strong mechanical joint between the cable and the tab 1504.

  FIG. 14 shows an outline of a substrate shape example. After reading this description, it will be clear to those skilled in the art how to implement antennas having tabs 1504 utilizing substrates having other shapes.

  FIG. 15 is a diagram illustrating one embodiment of a stacked antenna including example dimensions. In this embodiment, the first antenna 1304 is an L-band antenna and the second antenna 1308 is an S-band antenna. In this embodiment, the S-band antenna 1308 is an edge-coupled antenna, and each radiator 104 comprises two segments. Note that this embodiment is provided as an example only. Other frequency bands can be selected for operation. Further, it should be noted that either the first antenna 1304 or the second antenna 1308, or both, can utilize edge coupling techniques.

  Next, an example of dimensions for the L-band and S-band antennas shown in FIG. 15 will be described. The radiating aperture of the L-band antenna has a total axial height of 1.253 inches, whereas the S-band aperture has a total height of 1.400 inches. In this embodiment, the height of the feeding portion 412 of the first antenna 1304 is 0.400 inches. This results in a 3.093 inch total radiating aperture. The inclination angles of the radiators 104A to 104D are 65 °.

  The above dimensions are provided as examples only. As described with reference to a conventional helical antenna, the total length of radiators 104A-104D determines the exact resonant frequency of the antenna. The resonant frequency is important because the highest average gain and the most symmetric pattern occur at the resonant frequency. When the antenna is lengthened, the resonance frequency moves downward. Conversely, when the antenna is shortened, the resonance frequency moves upward. The percentage of frequency shift is approximately proportional to the percentage of lengthening or shortening radiators 104A-104D. At the operating frequency of the L band, a length of about 1 mm in the direction of the antenna axis corresponds to 1 MHz.

  In the illustrated embodiment, both the first antenna 1304 and the second antenna 1308 have four excited filer arms or radiators 104A-104D. Each of these radiators 104A-104D is fed in quadrature. Quadrature excitation of the four radiators 104A-104D for each antenna 1304, 1308 is implemented using a feed network. Although a conventional feed network that can provide quadrature excitation can be implemented, a preferred feed network is described below.

  Another important dimension is the feed point axis length. The feed point axial length limits the distance of the feed point from the feed network for the embodiment when the feed point is positioned along radiators 104A-104D as shown in FIG. The dimension of the feed point axial length indicates the position where the microstrip spreads to continue the radiator, and is actually the feed point position for the entire radiator 104. In the example illustrated in FIG. 15, the feed point axial length for the first antenna 1304 is 1.133 inches. The feed point axial length for the second antenna 1308 is 0.638 inches. These dimensions result in an impedance of 50Ω at 1618 and 2492 MHz, respectively. When the feed point position moves to a lower position, the impedance becomes lower. Conversely, if the power supply point position moves to a higher position, the impedance increases. Note that when adjusting the overall radiator length to tune the frequency, the feed point position should also be shifted by an amount proportional to the direction along the antenna axis to maintain correct impedance matching. It is important to.

  Preferably, an antenna having dimensions as illustrated in FIG. 15 is wound around a column having a diameter of 0.500 inches.

VI. Feeding Network The helical antenna described herein can be implemented using single wire, four wire, eight wire or other x-ray configurations. The feed network is used to provide signals for the filaments at the required phase angle. The feeding network separates the signals and shifts the phase provided for each line. The configuration of the feeding network depends on the number of lines. For example, in the case of a 4-wire helical antenna, the feed network provides four equal power signals in a quadrature relationship (ie, 0, 90, 180 and 270 °).

  A unique feed network layout may be utilized to maintain space in the antenna feed section. The feed network traces extend to one or more radiators 104A-104D of the antenna. For convenience, the feed network will be described with respect to a feed network designed to provide four equal power signals in quadrature relationship. It will be clear to those skilled in the art, after reading this description, how to implement a feed network for other x-ray configurations.

  FIG. 16 shows the electrical equivalent of a conventional quadrature feed network. In contrast to a conventional quadrature feed network, the network provides four equal power signals, each 90 degrees out of phase. The signal is provided to the feeding network via the first signal path 1704. At a first signal point A (referred to as a secondary feed point), a 0 ° phase signal is provided to the first radiator 104. At signal point B, a 90 ° phase signal is provided to the second radiator 104. At signal points C and D, 180 ° and 270 ° phase signals are provided to the third and fourth radiators 104.

  Signals A and B are mixed at point P2 resulting in an impedance of 25Ω. Similarly, signals C and D are mixed at point P3 which produces an impedance of 25Ω. These signals are mixed at P1, which produces an impedance of 12.5Ω. Therefore, to convert this impedance to 50Ω, a 25Ω 90 ° transformer is placed at the input. In the network shown in FIG. 16, a portion of the transformer is placed before P1 separates to shorten the feed and reduce losses. However, since it is before the split, the impedance must be doubled after the split.

  Conventional feed networks are placed on the portion of the substrate where traces of the feed network are limited for radiators 104A-104D. In particular, in a preferred embodiment, these traces are located on a substrate in a region opposite the ground trace of one or more radiators 104A-104D.

  FIG. 17 is a diagram illustrating an example of an embodiment of a power feeding network in a 4-wire helical antenna environment. In particular, in the example illustrated in FIG. 17, two power supply networks are illustrated, the first power supply network 1804 is for implementation with the first antenna 1304, and the second power supply network 1808 is with the second antenna 1308. This is for implementation. Feed networks 1804, 1808 have points A, B, C, D for providing 0, 90, 180 and 270 ° signals to radiators 104A-104D. The dotted line in FIG. 17 schematically shows the outline of the ground plane of the radiators 104A to 104D on the surface of the substrate facing the surface on which the feeding networks 1804 and 1808 are arranged. Thus, FIG. 17 shows these portions of the feed networks 1804, 1808 located in or extending to radiators 104A-104D.

  According to prior knowledge, the feeding network is designated for the feeding network and is provided in an area separated from the radiator. In contrast, the feed network described here is laid such that a portion of the feed network is located in the radiator portion of the antenna. Therefore, the size of the feeding portion of the antenna can be reduced as compared with the feeding portion for the conventional feeding network.

  FIG. 18 is a diagram illustrating feed networks 1804, 1808 with signal traces, including feed paths for antennas 1304, 1308. FIG. 19 schematically shows the ground plane of the antennas 1304 and 1308. FIG. 20 shows both the ground plane and the signal traces superimposed.

  The advantage of these feed networks is that the area required for the feed portion of the antenna to implement the feed network is reduced over conventional feed technologies. This is because the portion of the feed network that would otherwise be placed in the feed portion of the antenna is placed in the radiator portion of the antenna. As a result, the overall length of the antenna can be reduced.

  An additional advantage of such a feed network is that transmission line losses are reduced because the secondary feed point is moved closer to the antenna feed point. In addition, the transformer can be integrated into a routing network routing line for impedance matching.

  In this way, an area efficient network is configured such that a portion of the feed network is located in the radiator portion of the antenna and the remaining portion of the feed network is located in the feed portion. Since a part of the feeding network is arranged in the radiator part, the rest of the feeding network requires little area for the feeding part. As a result, the feeding portion of the antenna can be made smaller than that of an antenna having a conventional feeding network. Preferably, the feed network trace disposed in the radiator portion is disposed opposite the ground portion of the radiator. Thus, the grounded portion of the radiator acts as a ground plane for this portion of the feed network. An area efficient feed network can be implemented with many different types of antennas in varying configurations, including single-band and multi-band helical antennas. As a result of this configuration, the overall size of the antenna and the amount of loss in feeding are reduced as compared to an antenna having a conventional feeding network.

VII. Antenna Assembly As described above, one technique for manufacturing a helical antenna is to place a radiator, a feed network and a ground trace on the substrate, and wrap the substrate into a suitable shape. While the antenna configuration described above can be implemented using conventional techniques for wrapping the board in a suitable shape, an improved structure and technique for wrapping the board will now be described.

  FIG. 21A illustrates one embodiment of a structure used to maintain a substrate in a suitable shape (eg, a cylindrical shape). More specifically, FIG. 21A shows an example structure that can be added to an antenna having an area efficient feed network. After reading this description, it will be apparent to those skilled in the art how to implement the invention with other configurations of helical antennas.

  21B through 21F depict cross-sectional views of example structures used to hold the antenna in a cylindrical shape or other suitable shape. 21A-21F, an example structure includes a metal strip 2218 on or as an extension of the ground plane 412, solder material 2216 facing the metal strip 2218, and one or more vias 2210.

The metal strip 2218 may comprise a portion of the ground plane 412 or a metal strip attached to the ground plane 412. Preferably, in one embodiment, metal strip 2218 is provided by simply extending the width of ground plane 412 by a predetermined amount. In one embodiment shown in FIG. 21A, this width is indicated by w _strip .

  A series of vias 2210 are provided on the ground plane 412 in the region of the metal strip 2218. Preferably, a bias 2210 is added to the radiator portion of both the first antenna 1304 and the second antenna 1308 for a secure connection. The pattern chosen for Vias 2210 is based on the known mechanical and electrical properties of the materials used. While the invention can be implemented with only one or two vias 2210 on each ground plane 412 to obtain the desired level of mechanical strength and electrical connections, several vias 2210 may be used. . Although not necessarily required, the portion of each ground plane 412 used can extend horizontally or circumferentially beyond the antenna radiator.

  As seen in FIG. 21B, the vias 2210 extend completely through the support substrate 406 (100) from the material of the ground plane 412 and from one surface to the next. This via is manufactured as a metallized or metallized via using techniques known in the industry. A relatively small portion or portions of opposing edges 2214 of ground plane 412 are coated with solder material 2216.

  The embodiment shown in FIGS. 21B and 21D includes a small metal strip 2218 formed on the substrate 406 adjacent to the first edge 2212 and facing the ground plane 412. In this embodiment, the vias extend through the substrate to the metal strip 2218. Metal strip 2218 is not necessary for all applications, but it will be readily apparent to those skilled in the art that metal strip 2218 facilitates solder flow and facilitates improved mechanical bonding. The special material from which the metal strip 2218 is made is selected according to known principles based on the ground plane material used, the solder selected, and the like.

  When the antenna support substrate is rolled into a generally cylindrical shape to form the desired helical antenna structure, the edges 2212 and 2214 are positioned in close proximity to each other, as shown in FIG. 21D. The vias 2210 and metal strip 2218 (if provided) are positioned such that the solder material 2216 overlies the opposite ground plane edge 2214. Heat is applied using known soldering techniques and equipment while holding the strip 2218 in contact with the solder material 2216.

  As the solder material 2216 melts, it flows to the bias 2210 and onto the metal strip 2218. The heat is then reduced or removed to form a bond or bond between the two outer edges or ends of the ground plane 412 where the solder is permanent but can be removed or held. In this way, the antenna support substrate 406 and the antenna component disposed thereon are mechanically held in the desired cylindrical shape without the need for other materials such as dielectric tape, adhesive, and the like. This reduces the time, cost and effort previously required to assemble this type of helical antenna. This not only increases the automation of its operation, but also provides more, antenna dimensions that can be easily reproduced. In addition, one edge of the ground plane 412 is electrically connected to the other edge to provide a conductive ring continuous from the ground plane as desired. This electrical connection is achieved without complicated soldering or connecting wires.

  This technique can be extended to provide support or engagement along other parts of the antenna. For example, a series of one or more metal pads or strips 2220 can be placed at spaced locations along the length of the radiators of one or both sets of antennas. As seen in FIG. 21E, a metal pad or strip 2220 is positioned on the opposite side of the support substrate 406 (100) adjacent to the one or more radiators 104A-D. When the antenna substrate is rolled or bent to make the desired antenna, as shown in FIG. 21F, the metal pads or strips 2220 are over the portions of the radiators 104A-D at the opposite edges of the support substrate. These pads or strips are positioned so that they are positioned in In particular, in one embodiment, metal pad or strip 220 is positioned over ground trace 1436 of radiators 104A-D. Metallized vias may be formed on the pads 2220 if desired for the application, or to improve heat transfer to melt the solder.

  If a small amount of solder 2226 is pre-applied to the engagement portion of the surface of ground trace 1436, these radiators can be used to join the strip. This provides an additional joint or bond point that effectively holds the antenna structure together in the desired shape. If an electrical connection is desired, metallized vias can be formed on pads or strips that extend to the opposite side. These pads can be used with or without the strips described above for the ground plane. Such a structure is very useful when very long radiators resulting in long antenna structures, or multiple stacks of antenna radiators are contemplated.

  22A-22C show a series of views of an example embodiment of a mold 2310 that is used to wind the substrate 406 into a desired shape. The example illustrated in FIG. 22 is a cylindrical mold 2310 used when winding an antenna to provide continued support and rigidity for the antenna structure. In one embodiment, the mold 2310 is provided with a series of prongs or teeth 2312 extending radially outward from the outer surface of the mold 2310. A series of “tooling” or “assembly guide” holes or passages 2230 are provided in the substrate 406 for engaging the teeth 2312 to connect the mold 2310 and the teeth 2312.

  In FIG. 21A, the embossing hole 2230 is illustrated as being positioned in the ground plane 412. The metal material of the ground plane 412 functions to reinforce the hole and prevent deformation and movement when a relatively soft support substrate material is used. This aids alignment accuracy for the antenna structure. However, there is no requirement to place holes 2230 in the metal layer.

  Referring again to FIGS. 22A-22C, starting from the perspective view of FIG. 22A, the substrate 406 is shown positioned to engage the support mold 2310 by engagement of the teeth 2312 with the holes 2230. FIG. . As seen in the side views of FIGS. 22B and 22C, holes 2230 engage teeth 2312 as support mold 2310 rotates about its axis or as substrate 406 is wound around support mold 2310; It helps to position the substrate 406 in place against or above the support mold 2310. Finally, the entire substrate 406 engages with the support mold 2310. In FIG. 22C, as described above, the substrate 406 is illustrated as being wrapped around the support mold 2310 until the substrates themselves overlap so that the strips 2218, 2220 engage the solders 2216, 2226.

  Of course, if the strips 2218, 2220 and solder 2216, 2226 are not used to join the substrate portions, then the substrate 406 need not overlap on the support mold 2310. Further, there is no requirement that support mold 2310 extend the entire length of antenna, radiators 104A-D or substrate 406. In some applications, all or part of the antenna may be self-supporting without the need for the mold 2310. This feature is advantageous, for example, to minimize the effect of mold 2310 on the radiation pattern at a particular frequency.

  For clarity and ease of illustration, only the substrate 406 is shown in FIGS. 22A-22C, and the ground plane material layer, radiator, feed, feed network, etc. are not shown. It will be clear to those skilled in the art how to size hole 2230 to match the dimensions of teeth 2312.

  As shown in FIG. 22, the mold 2310 is constructed using a solid or hollow structure formed in a cylindrical or other desired shape with teeth or prongs 2312 protruding therefrom. Can do. In this embodiment, the mold 2310 can be thought of as, for example, a toothed drum variant found in many music boxes. Upon reading this disclosure, other structures can be implemented to provide a mold 2310 that includes an axle / spoke arrangement, an axle / sprocket arrangement, or other suitable configuration, as will be apparent to those skilled in the art.

  Note that it is contemplated that the spacing of the prongs 2312 or spokes may not be symmetrical about the support component. That is, some spacing is applied to provide a consistently large amount of tension during rolling and a small amount of tension in certain areas to better control the positioning of the substrate where the substrate edges overlap. It may grow in parts. Preferably, the tooth spacing is chosen such that the teeth 2312 apply a certain amount of tension to hold the substrate 406 in place and make the overall assembly a more rigid structure.

  The use of holes 2230 and teeth 2312 provides improved manufacturing capabilities in the precise placement or positioning of the substrate on the mold through placement and assembly automation and which can be mounted within the antenna radome. . This allows for a more precise structural definition and positioning of the antenna assembly, allowing more precise control and compensation for radome effects on the radiation pattern.

  The above description of the placement of metal strip 2218, solder material 2216, and bias 2210 has been provided as an example. After reading this description it will be apparent to one skilled in the art that these components may be placed in different locations depending on the desired configuration. For example, these components can be positioned so that the antenna can be wound to have circular polarization of the right or left hand and to have radiators 104A-D either inside or outside the shape. it can.

VIII. CONCLUSION While various embodiments of the present invention have been described, it should be understood that they have been presented by way of example only and not limitation. Thus, the breadth and scope of the present invention should not be limited by any of the above-described exemplary embodiments, but should be limited only in accordance with the following claims and their equivalents.

  The previous description of the preferred embodiments is provided to enable any person skilled in the art to use the invention. While the invention has been illustrated and described, particularly with reference to preferred embodiments thereof, those skilled in the art will recognize that various changes in form and detail can be made without departing from the spirit and scope of the invention. Will.

It is a figure which shows the conventional wire 4-wire helical antenna. It is a figure which shows the conventional strip 4-wire helical antenna. It is a figure which shows the plane display of the 4-wire helical antenna by which the open circuit or the open termination | terminus was carried out. It is a figure which shows the planar display of the short-circuited 4-wire helical antenna. It is a figure which shows the electric current distribution on the radiator of the short-circuited 4-wire helical antenna. FIG. 3 shows the distal and proximal surfaces of an etched substrate of a strip helical antenna. It is a figure which shows the perspective view of the board | substrate with which the strip helical antenna was etched. FIG. 3 illustrates an open coupled multi-segment radiator having five coupled segments according to an embodiment of the invention. FIG. 2 illustrates a pair of short-coupled multi-segment radiators according to one embodiment of the invention. FIG. 3 is a diagram illustrating a planar view of a short-coupled multi-segment 4-wire helical antenna according to an embodiment of the invention. 1 illustrates a coupled multi-segment 4-wire helical antenna formed in a cylindrical shape according to one embodiment of the invention. FIG. FIG. 6 shows an overlap δ and spacing s of radiator segments according to an embodiment of the invention. It is a figure which shows the example of the electric current distribution on the radiator segment of a joint multi segment helical antenna. It is a figure which shows the 2 point source radiation signal from which a phase differs only 90 degrees. It is a figure which shows the field pattern for the point sources shown by FIG. 9A. It is a figure which shows the circular polarization field pattern for the conventional helical antenna, and the circular polarization field pattern for the helical antenna which has the feed tab aligned with the axis | shaft of an antenna. FIG. 5 shows an embodiment in which each segment is located equidistant from a segment on either side. FIG. 3 is a diagram illustrating an example of a combined multi-segment antenna implementation according to an embodiment of the invention. FIG. 4 is a diagram illustrating a planar view of the surface of a stacked dual band helical antenna according to an embodiment of the invention. FIG. 4 shows a planar view of the surface of a stacked dual band helical antenna according to an embodiment of the invention, where the feed point for the radiator is located a little away from the feed network. FIG. 4 shows a planar view of a tab used to feed one antenna of a stacked dual band helical antenna according to an embodiment of the invention. FIG. 5 shows an example of dimensions for a stacked dual band helical antenna according to an embodiment of the invention. It is a figure which shows an example of the conventional quadrature feeding network. 1 illustrates a feed network having a portion that extends to a radiator of an antenna according to an embodiment of the invention. FIG. 1 shows a feed network with signal traces including feed paths for an antenna according to an embodiment of the invention. FIG. It is a figure which shows the external shape of the ground plane of the antenna by one Embodiment of invention. FIG. 4 is a diagram illustrating a ground plane and signal traces of a dual band antenna superimposed according to an embodiment of the invention. FIG. 6 illustrates a structure for maintaining a cylindrical or other suitable shaped antenna according to one embodiment. FIG. 21B illustrates the formation of a cylindrical or other suitably shaped antenna according to the embodiment shown in FIG. 21A. FIG. 21B illustrates the formation of a cylindrical or other suitably shaped antenna according to the embodiment shown in FIG. 21A. FIG. 21B illustrates the formation of a cylindrical or other suitably shaped antenna according to the embodiment shown in FIG. 21A. FIG. 21B illustrates the formation of a cylindrical or other suitably shaped antenna according to the embodiment shown in FIG. 21A. FIG. 4 illustrates a shape suitable for use in supporting a cylindrical or other suitable shaped antenna according to one embodiment. FIG. 22B illustrates the formation of a cylindrical or other suitably shaped antenna according to the embodiment shown in FIG. 22A. FIG. 22B illustrates the formation of a cylindrical or other suitably shaped antenna according to the embodiment shown in FIG. 22A.

Claims (20)

substrate;
A radiator portion comprising a plurality of radiators disposed on the substrate, the substrate being shaped such that the radiator is configured in a spiral;
A feed portion adjacent to the radiator portion and comprising a substrate;
A feed network comprising a first set of one or more traces disposed on the substrate of the feed portion and a second set of one or more traces disposed on the substrate of the radiator portion;
A helical antenna comprising:   The helical antenna of claim 1, wherein the set of one or more traces disposed in the radiator portion are disposed in a region of the radiator portion that is defined for the plurality of radiators.   2. The radiators each comprising a ground trace, wherein the one or more traces of the set of feed networks disposed in the radiator portion are disposed on a surface of the substrate opposite the ground trace. Or the helical antenna of 2.   The helical antenna of claim 3, wherein the trace includes copper.   The helical antenna according to any one of the preceding claims, wherein the helical antenna is a 4-wire, 2-wire or other x-ray antenna.   A helical antenna according to any preceding claim, wherein the radiator comprises strip segments deposited on the substrate.   The helical antenna according to any one of the preceding claims, wherein the substrate is formed in a cylindrical, conical or other suitable shape.   The helical antenna according to any one of the preceding claims, wherein the radiator portion comprises four radiators disposed on the substrate, and the feed network provides quadrature signals to the four radiators. . A first set of one or more traces disposed in the feed portion of the antenna;
A second set of one or more traces disposed in the radiator portion of the antenna and a feed network comprising.   The feed network of claim 9, wherein the second set of one or more traces disposed in the radiator portion are disposed in a region of the radiator portion defined for the plurality of radiators. .   10. The radiators each comprising a ground trace, wherein one or more traces of the set of the feed network disposed in the radiator portion are disposed on a surface of the substrate opposite the ground trace. The power supply network according to 10.   The feed network of claim 11, wherein the trace comprises copper.   The feed network according to any one of claims 9 to 12, wherein the antenna is a 4-wire, 2-wire or other x-ray helical antenna.   14. The feed network according to any one of claims 9 to 13, wherein the antenna comprises a substrate and the trace is deposited on the substrate.   15. The feeding network of claim 14, wherein the substrate is formed in a cylindrical shape, a conical shape, or other suitable shape.   16. A feed network according to any one of claims 9 to 15, wherein the antenna comprises four radiators, and the feed network provides quadrature signals to the four radiators. A first power feeding network disposed on a first side surface of a substrate of a first power feeding portion of the first antenna; a first ground plane disposed on a second side surface of the substrate facing the power feeding network; And a first antenna portion comprising a first set of one or more radiators disposed on the substrate and extending from the feeder network; and a second feeder network disposed on the substrate of a second feeder portion; A second antenna portion comprising a second ground plane disposed on the substrate facing the feed network and a second set of one or more radiators disposed on the substrate and extending from the feed network. Providing a path for current flowing from the radiator of the second antenna along the axis of the second antenna, thereby increasing the energy radiated in a direction perpendicular to the axis Includes a stage, a;
Wherein the first feed network includes a first set of one or more traces disposed in the first feed portion of the antenna and a second set of radiators disposed in the radiator portion of the first antenna portion. One or more traces, wherein the second feed network includes a third set of one or more traces disposed in the second feed portion and a radiator portion of the second antenna portion. A fourth set of one or more traces disposed;
Dual band helical antenna.   The antenna of claim 17, wherein the second set of one or more traces disposed in the radiator portion are disposed in a region of the radiator portion that is defined for the plurality of radiators.   The radiators each comprising a ground trace, wherein the one or more traces of the set of the feeding network disposed in the radiator portion are disposed on a surface of the substrate opposite the ground trace. The antenna according to 17 or 18.   Two sets of tracks are provided on a common substrate formed on a curved surface, the tracks follow each substantially helical path, and the feed network coincides with a portion of the set of tracks. Characteristic antenna.

Images