A high-sensitivity ultra-wideband receiving antenna

Abstract

This invention belongs to the field of wireless communication technology, specifically disclosing a high-sensitivity ultra-wideband receiving antenna, comprising: a substrate; absorbers formed on the front and back sides of the substrate by copper etching; at least a portion of the width of each absorber gradually narrows; a receiver array formed on the front side of the substrate by copper etching; the receiver array includes multiple receiver conductors, all of which are arranged sequentially along a direction perpendicular to the extension direction, and the lengths of each receiver conductor along the extension direction are distributed in a geometric sequence; a feed point is disposed on the substrate and connected to the wider end of each absorber; the feed point is used to transmit the radio frequency signal received by the receiver array and extracted through the absorber; it has the following advantages: a single board integrates a broadband antenna, eliminating the need for multiple antenna switching; seamless frequency splicing of the geometric array, resulting in flat gain; trapezoidal absorption matching with low VSWR; low loss at the center feed point; compact structure, low cost, flexible application, easy maintenance, and high portability.

Description

Technical Field

[0001] This invention relates to the field of wireless communication technology, and more specifically, to a high-sensitivity ultra-wideband receiving antenna. Background Technology

[0002] Currently, if a radio receiver is desired to cover an ultra-wide frequency range of 20MHz to 8000MHz, it is generally impossible to achieve complete coverage with a single receiver using existing technologies. To meet the signal reception requirements of different frequency bands, a common technical approach is to adopt a frequency-band design and a multi-antenna combination strategy. This involves building receivers with different structures for low-frequency, mid-frequency, and high-frequency bands, and then integrating them for use through a radio frequency switching network.

[0003] The main existing technical solutions include: in the low frequency band (20MHz to 300MHz), by loading inductive elements (such as inductors) or using high permeability materials, and designing structures such as helical antennas and stubbed inverted-F antennas to compress the physical size and improve low frequency reception efficiency; in the mid frequency band (300MHz to 3GHz), log-periodic antennas or tapered broadband dipole structures are often used to extend the bandwidth by utilizing their relatively flat radiation pattern and stable impedance characteristics; in the high frequency band (3GHz to 8GHz), tapered slot line structures (such as Vivaldi antennas) or multi-resonant microstrip patch arrays are often used to adapt to the reception characteristics of microwave frequency band signals.

[0004] While the aforementioned technologies perform well within their respective frequency bands, they present the following challenges in practical deployment: The construction of independent receiving modules for multiple frequency bands results in a complex and bulky overall device structure, making integration into a single substrate or housing difficult, particularly unsuitable for portable or rapidly deployable monitoring scenarios; multiple receiving paths involve multiple RF links, front-end tuners, and signal processing modules, increasing manufacturing costs and post-maintenance complexity; relying on segmented switching mechanisms (such as RF switchmatrix) to switch receiving paths between different frequency bands may introduce additional losses or system delays; segmented structures are prone to discontinuities in receiving performance or gain dips at frequency junctions, making it difficult to meet the requirements for high-fidelity reception of continuous spectrum; and currently, no integrated receiving antenna solution has been found that can operate continuously across the entire 20MHz–8000MHz frequency range with high-gain output.

[0005] To address these issues, a high-sensitivity ultra-wideband receiving antenna is proposed. Summary of the Invention

[0006] The present invention aims to provide a high-sensitivity ultra-wideband receiving antenna to solve or improve the problem that it is difficult to achieve continuous, high-gain, and high-fidelity signal reception over an ultra-wide frequency range using a single device, resulting in complex system structure, poor frequency band interoperability, and high integration cost.

[0007] In view of this, a first aspect of the present invention is to provide a high-sensitivity ultra-wideband receiving antenna.

[0008] A first aspect of the present invention provides a high-sensitivity ultra-wideband receiving antenna, comprising: a substrate; absorbers formed on the front and back sides of the substrate by copper etching; wherein the width of at least a portion of each absorber gradually narrows along an extending direction to perform standing wave suppression and impedance matching for multiple frequency band signals within a preset frequency band range; a receiver array formed on the front side of the substrate by copper etching; the receiver array comprising multiple receiver conductors, all of which are arranged sequentially along a direction perpendicular to the extending direction, and the lengths of each receiver conductor along the extending direction are distributed in a geometric sequence to segmentally cover the signal reception range of different frequency bands within the preset frequency band range; and feed points disposed on the substrate and connected to the larger ends of the absorbers; the feed points are used to transmit radio frequency signals received by the receiver array and extracted through the absorbers.

[0009] In any of the above technical solutions, the absorber is located on the central axis of the front and back sides of the substrate; the receiver array consists of two receivers, which are symmetrically arranged on the front side of the substrate with the absorber as the axis of symmetry.

[0010] In any of the above technical solutions, within the same receiver array, adjacent receiver conductors are formed with equal preset gaps; the value of the preset gap ranges from 0.4mm to 0.5mm.

[0011] In any of the above technical solutions, with the absorber as the axis of symmetry, the length ratio between the receiving conductors at symmetrical positions is a first preset value; the range of the first preset value is 1.1 to 1.3.

[0012] In any of the above technical solutions, within the same receiver array, the length ratio between adjacent receiver conductors is a second preset value; the value of the second preset value ranges from 1.4 to 1.6.

[0013] In any of the above technical solutions, all the receiving conductors are connected to the wide end of the absorber via horizontal trace conductors, which are used to feed the signals captured by the receiver array into the feed point.

[0014] In any of the above technical solutions, the size parameters of the absorber are set according to the preset frequency band range; there is a width ratio between the small end and the large end of the absorber, and the value of the width ratio is in the range of 0.1 to 0.2; there is a length-to-width ratio between the large end of the absorber and the length and the large end of the width along the extension direction, and the value of the length-to-width ratio is in the range of 150 to 200.

[0015] In any of the above technical solutions, the receiver conductor with the largest length value in one of the receiver arrays is connected to a patch structure through an edge trace conductor; the edge trace conductor extends along the front edge of the substrate, and the patch structure is located on one side of the absorber.

[0016] In any of the above technical solutions, there is a frequency ratio between the highest and lowest operating frequencies within the preset frequency band, and the value of the frequency ratio ranges from 305 to 450.

[0017] In any of the above technical solutions, the number of receiving conductors in the two sets of receiving arrays is set according to the preset frequency band range and in combination with the geometric series coefficients of the length of the receiving conductors.

[0018] The beneficial effects of this invention compared to the prior art are as follows:

[0019] A receiving antenna with a single structure can continuously receive multi-band signals over an ultra-wideband range, avoiding the complex switching networks of traditional multi-antenna combinations with frequency bands. This significantly reduces structural complexity and system size, improving the portability and rapid deployment capability of the overall device. By utilizing the geometrical distribution of conductor lengths in the receiver array, the resonant points of signals from each frequency band are continuously spliced ​​together, eliminating gain dips at frequency band boundaries and achieving stable, continuous, and high-fidelity receiving gain characteristics across the entire frequency range. Through the trapezoidal width-gradient structure and symmetrical layout of the absorber, standing wave suppression and continuous impedance matching of signals from different frequency bands are effectively achieved, avoiding multipath reflections and high-frequency signal distortion, and improving the phase consistency and standing wave stability of the signal output. The feed point is directly connected to the wide end of the absorber, and the compact structure further reduces signal transmission path loss and improves the energy conversion efficiency of RF signals from the receiver to the output. In addition, the compact design of the overall structure and the PCB etching process reduce the number of RF link components, lowering the cost of equipment manufacturing and maintenance, making the device more economical and engineering-adaptable.

[0020] Additional aspects and advantages of embodiments of the invention will become apparent in the following description or may be learned by practice of embodiments of the invention. Attached Figure Description

[0021] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0022] Figure 1 This is a front view of the present invention;

[0023] Figure 2 This is a schematic diagram of the rear side of the present invention;

[0024] Figure 3 for Figure 1 A larger image is shown in section A;

[0025] Figure 4 This is a partial view of the present invention;

[0026] Figure 5 This is a line graph showing the standing wave ratio effect of the present invention;

[0027] Figure 6 This is a line graph showing the gain effect of the present invention.

[0028] in, Figures 1-6 The correspondence between the reference numerals and component names in the attached drawings is as follows:

[0029] 1. Substrate, 2. Absorber, 201. Trapezoidal structure, 202. Columnar structure, 3. Receiver array, 301. Receiver conductor, 4. Feed point, 5. Horizontal trace conductor, 6. Edge trace conductor, 7. Patch structure. Detailed Implementation

[0030] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0031] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and therefore the scope of protection of the invention is not limited to the specific embodiments disclosed below.

[0032] Please see Figures 1-6 The following describes a high-sensitivity ultra-wideband receiving antenna according to some embodiments of the present invention.

[0033] An embodiment of the first aspect of the present invention provides a high-sensitivity ultra-wideband receiving antenna. In some embodiments of the present invention, such as... Figures 1-6 As shown, the high-sensitivity ultra-wideband receiving antenna includes:

[0034] Substrate 1; Substrate 1 is a printed circuit board (PCB). The substrate of the PCB is FR-4, with double-sided copper cladding. The PCB dimensions are 26.4mm × 547.4mm. The thickness is 0.8mm. The double-sided copper cladding consists of two sides: a top layer and a bottom layer. Both the top and bottom copper foils have a thickness of 0.035mm.

[0035] Absorber 2, which is formed on the front and back sides of substrate 1 by copper etching; along an extension direction, at least part of the width of each absorber 2 gradually narrows to suppress standing waves and impedance matching for multiple frequency band signals within a preset frequency band range.

[0036] The receiver array 3 is formed on the front side of the substrate 1 by copper etching. The receiver array 3 includes multiple receiver conductors 301, all of which are arranged sequentially along the direction perpendicular to the extension direction. The lengths of each receiver conductor 301 along the extension direction are distributed in a geometric sequence to segmentally cover the signal reception range of different frequency bands within the set frequency band.

[0037] Feed point 4 is located on substrate 1 and connected to the wider end of absorber 2. Feed point 4 transmits the radio frequency signals received by receiver array 3 and extracted from absorber 2. The outer conductor of the coaxial cable, such as braided mesh or copper tubing, is soldered to the pad, while the inner conductor (core wire) of the coaxial cable is soldered to feed point 4. The size of the pad is sufficient to solder the outer sheath of the coaxial cable. The gap between feed point 4 and the pad is 1mm. The trace width of feed point 4 is 2.6mm, symmetrical about the board center. Directly connected to feed point 4 and traced upwards is the lower half of the absorber's top conductor; its width is the same as feed point 4, 2.6mm. The length of the lower half of the absorber's top conductor is 10.5mm, including the 0.5mm vertical length of feed point 4.

[0038] This invention provides a high-sensitivity ultra-wideband receiving antenna. The basic component is a substrate 1, which is a printed circuit board (PCB) used to support the overall receiving structure and serve as the physical carrier for radio frequency signal transmission. The PCB uses FR-4 as the dielectric material, maintaining low dielectric loss under high-frequency signal conditions, which is beneficial to improving the signal integrity and environmental stability of the entire receiving device. The PCB has a double-sided copper-clad structure, meaning that copper foil layers are laid on both its front and back sides, forming two conductive surfaces: a top layer and a bottom layer. The thickness of each copper foil layer is 0.035mm, possessing good conductivity and processing stability, providing a reliable metal path for signal transmission, coupling, and reception. The PCB substrate 1 is generally a long and narrow rectangle, measuring 26.4mm × 547.4mm, with a thickness of 0.8mm. This elongated structural design meets the requirements of multi-unit receiving array arrangement while also considering the compact size and mechanical installability of the device. The double-sided copper foil not only allows for the placement of functional unit structures on the top and bottom layers respectively, but also enables electrical signals to be electrically connected between different layers via vias, thereby optimizing the spatial distribution of the signal flow path.

[0039] The absorber 2 is formed by etching copper foil on the front and back sides of the substrate 1, creating a symmetrical overall layout. The absorbers 2 are arranged along the longitudinal extension direction of the substrate 1, and each absorber 2 exhibits a gradually narrowing width design in this direction, meaning its width gradually narrows from the end closer to the signal convergence point to the end farther from the feed point 4, forming a non-uniform conductor strip with trapezoidal geometry. When a broadband signal is injected into the absorber 2 by the receiver array 3, electromagnetic waves of different frequencies will form standing wave responses at different cross-sectional positions of the absorber 2. The absorber 2, through its continuously varying cross-sectional impedance characteristics, effectively achieves a smooth transition from the receiver output impedance to the feed point 4 output impedance. This process significantly reduces the standing wave ratio (VSWR), decreases signal reflection, and improves the transmission efficiency of the RF signal along the direction of the absorber 2.

[0040] Furthermore, since the absorber 2 structure is simultaneously deployed on both the front and back sides of the PCB, and forms an upper and lower conductive connection through vias near feed point 4, a closed loop or symmetrical transmission path can be formed while maintaining the overall structural compactness. This allows for balanced compensation of odd-even mode interference under wideband conditions, improving the stability of multi-frequency signal coupling. The front and back structures of absorber 2 work together to participate in signal conduction, ensuring that signals of different frequency bands can achieve effective impedance matching and energy convergence on their respective physical paths.

[0041] The receiver array 3 is formed by etching on the copper foil on the front side of the substrate 1, and multiple receiving conductors 301 are sequentially arranged along the transverse direction of the substrate 1, that is, perpendicular to the longitudinal direction extending from the absorber 2. The receiving conductors 301 have a linear conductor structure, are evenly spaced on the front side of the substrate 1, are independent of each other but collectively form a linear array, and the entire array is arranged on the left and right sides of the absorber 2 as its axis of symmetry, thus forming a receiving unit cluster with both structural and electrical symmetry. The lengths of the receiving conductors 301 in the extending direction are set according to a set geometric sequence, that is, the length ratio between any two adjacent receiving conductors 301 remains within a set coefficient range. This geometric sequence construction gives the receiver array 3 segmented selectivity in frequency response: shorter receiving conductors 301 are more sensitive to high-frequency signals, while longer receiving conductors 301 are suitable for receiving low-frequency signals, thereby forming multiple frequency band coverage areas. In this way, the entire receiver array 3 achieves continuous coverage from low frequency to high frequency in its physical structure, ensuring good reception performance in an ultra-wide bandwidth range of 20MHz to 8000MHz.

[0042] Each receiving conductor 301 is electrically connected to the absorber 2 via a corresponding horizontal trace, enabling the captured radio frequency signal to be effectively guided into the path of the absorber 2 for convergence processing. Because the lengths of the receiving conductors 301 vary progressively and maintain a stable spacing in the structure, frequency band distribution control of the electromagnetic response can be achieved within the entire array, avoiding interference coupling between signals of different frequencies and improving the selectivity and stability of the system in multi-frequency environments.

[0043] Feed point 4 is mounted on substrate 1 and located on the longitudinal central axis of the entire printed circuit board. Its geometric position is precisely aligned with the wider end of absorber 2, and it is electrically connected via a copper foil conductor. Feed point 4 plays a crucial role in transmitting RF signals from the antenna structure to external receiving systems (such as front-end amplifiers and signal analyzers), serving as the electrical interface node between the internal signal path and the external RF link. Specifically, feed point 4 is used to solder the inner conductor (core wire) of the RF coaxial cable, enabling the centralized output of multi-frequency signals converged from absorber 2. The conductor width of feed point 4 is designed to be 2.6 mm, and with the center of antenna substrate 1 as the symmetry reference, signals are guided from the wider ends of absorber 2 on both sides. The high-frequency signal merging and transmission are achieved through the centrally symmetrical feed point 4 path, maintaining the symmetry of the entire structure. This helps reduce signal offset caused by dipole electric field imbalance and improves impedance matching performance.

[0044] Above feed point 4 is the lower half of the top copper foil structure of absorber 2. This structure continues the trace width of feed point 4, also 2.6mm, and conducts vertically upwards. The total length of this lower half conductor is 10.5mm, including the overlapping area with the solder joint of feed point 4. Feed point 4 itself occupies 0.5mm in the vertical direction, forming a continuous and smooth RF path. This ensures that the signal from multiple receivers converges to absorber 2 via horizontal traces, and is finally introduced to feed point 4 efficiently and with low loss through this lower half conductor. A 1mm insulation gap is provided between feed point 4 and the pad. This structure is used for physical and electrical isolation, ensuring that feed point 4 is only connected to the inner conductor portion of the coaxial cable, while the pad is located in the surrounding area for soldering the outer conductor of the coaxial cable, such as braided mesh or copper tubing. The pad size is designed to fit the outer sheath size of a standard coaxial connector, ensuring controllable soldering process and stable mechanical connection. At the same time, by soldering the outer conductor to the pad connected to the ground copper layer, a low-impedance connection between the antenna system and the reference ground is achieved, which is beneficial to the electromagnetic compatibility (EMC) and transmission stability of the entire RF system.

[0045] In summary, by integrating the equally long receiver array 3, the symmetrical trapezoidal non-uniform transmission line absorber 2, and the center feed point 4 / pad isolation structure onto a single double-sided copper-clad FR-4 PCB, continuous, high-gain signal reception with a bandwidth ratio of approximately 400:1 from 20MHz to 8GHz is achieved. This fundamentally eliminates the cumbersome solution of traditional multi-antenna switching networks in frequency division. The entire unit is lightweight and easy to deploy quickly. The internal trapezoidal absorber 2 achieves impedance gradient and VSWR suppression over a wide bandwidth, eliminating the need for external baluns or matching units. Thus, while ensuring high sensitivity and a flat gain curve, RF loss is significantly reduced. The symmetrical layout and the 41mm insulation gap between the pad and feed point jointly suppress common-mode interference, improving electromagnetic compatibility and anti-interference capabilities. With minimal structural components and a single-piece PCB fabrication, manufacturing and maintenance costs are significantly reduced. Ultimately, this provides a truly one-piece, full-band, high-performance, and cost-effective receiving antenna solution for cross-frequency domain scenarios such as spectrum monitoring, mobile communication testing, drone countermeasures, and jewelry purity testing.

[0046] In any of the above embodiments, the absorber 2 is located on the central axis of the front and back sides of the substrate 1; two receiver arrays 3 are provided and are symmetrically arranged on the front side of the substrate 1 with the absorber 2 as the axis of symmetry.

[0047] In this embodiment, the absorber 2 is placed on the same central axis on the front and back sides of the substrate 1, so that the top and bottom layers form a non-uniform transmission line channel that is electrically and geometrically completely symmetrical. High-frequency and low-frequency signals achieve continuous impedance matching with gradual changes in the longitudinal direction. The two sets of receiver arrays 3 are arranged on the left and right sides with the central absorber 2 as the axis of symmetry. They can capture electromagnetic wave energy incident from the left and right sides in a balanced manner in space, avoiding directional imbalance caused by single-sided wiring. The multi-frequency signals are equidistantly fed into the central absorber 2 through horizontal wiring. The symmetrical structure on the front and back suppresses common-mode noise and dipole unbalanced radiation. The symmetrical array on the left and right sides cancels lateral coupling and mode tilt, thereby achieving a comprehensive operating effect of flat gain curve, symmetrical radiation pattern, low VSWR and consistent signal output phase throughout the entire 20MHz-8GHz bandwidth.

[0048] Specifically, the absorber 2 includes a gradually narrowing trapezoidal structure 201 and a columnar structure 202 with the same width. The columnar structure 202 is connected to the feed point 4. The trapezoidal structure 201 is connected to the columnar structure 202. The narrow end of the absorber 2 is located at the end of the trapezoidal structure 201 that is far away from the columnar structure 202, and the wide end of the absorber 2 is located at the end of the columnar structure 202 that is far away from the trapezoidal structure 201.

[0049] Specifically, it is connected to an N-type RF connector via a coaxial line soldered to the feed point and the top pad. The RF connector is then connected to a receiver, and the radio waves received by the device are transmitted to the receiver.

[0050] Specifically, the length of the receiving conductor is shown in the table below:

[0051]

[0052] As mentioned above, the edge spacing between the 11th and 12th receivers is 5mm.

[0053] In any of the above embodiments, within the same receiver array 3, an equal preset gap is formed between adjacent receiver conductors 301.

[0054] The preset gap ranges from 0.4mm to 0.5mm; preferably 0.5mm.

[0055] In this embodiment, in each receiver array 3, the edge gap between adjacent receiver conductors 301 is uniformly set to 0.4mm-0.5mm. This balances electromagnetic coupling and isolation across the entire 20MHz-8GHz wideband range: the gap is narrow enough to ensure necessary near-field coupling between adjacent conductors, allowing each receiver conductor 301, after being designed with equal lengths, to form a continuous, gap-free receiving bandwidth in adjacent sub-bands; yet it is also wide enough to avoid excessive coupling capacitance at high frequencies, thus suppressing crosstalk, standing wave distortion, and gain dip. The equal gap also maintains the periodic consistency of the array impedance distribution, ensuring a balanced lateral electric field generated by the symmetrical arrays and maintaining a smooth and symmetrical radiation pattern; simultaneously, it simplifies PCB etching tolerance requirements, improves batch manufacturing consistency, and enhances the repeatability of the antenna in different environments.

[0056] In any of the above embodiments, with the absorber 2 as the axis of symmetry, the length ratio between the receiving conductors 301 in symmetrical positions is a first preset value.

[0057] The first preset value ranges from 1.1 to 1.3; preferably it is 1.2.

[0058] In this embodiment, the left and right sets of receiving conductors 301 are arranged in a mirror image along the central axis of the absorber 2, and the lengths of the conductors at symmetrical positions are designed with a fixed ratio of 1.1-1.3. This allows for a slight misalignment of the resonant frequencies on the left and right sides without disrupting electrical symmetry: when a standing wave dip occurs on the left conductor at a certain frequency, the corresponding conductor on the right, due to its slightly longer (or shorter) length, is in a relatively high-gain region, and vice versa. This mutual compensation of the resonant curves on both sides can "fill in" the narrowband gain troughs that may occur on a single-sided array, resulting in a flatter amplitude response for the antenna in the 20MHz-8GHz range. Furthermore, the ratio of 1.1-1.3 is sufficiently small to avoid introducing significant radiation direction skew or common-mode imbalance, yet large enough to generate the necessary frequency misalignment for bandwidth splicing, thereby comprehensively improving broadband gain continuity, pattern symmetry, and resistance to multipath fluctuations.

[0059] In any of the above embodiments, within the same receiver array 3, the length ratio between adjacent receiver conductors 301 is a second preset value.

[0060] The second preset value ranges from 1.4 to 1.6; preferably it is 1.5.

[0061] In this embodiment, broadband continuous splicing is achieved at the electromagnetic resonance mechanism level. Each conductor generates a main resonant point at its corresponding half-wavelength or quarter-wavelength, and the length ratio is inversely proportional to the resonant frequency ratio. When the ratio is 1.5, the resonant frequency ratio of adjacent conductors is approximately 0.67:1, which is equivalent to forming an overlap region of about 33% between two adjacent sub-bands; within the ratio range of 1.4-1.6, the overlap bandwidth remains within an adjustable range of 28%-38%. In this way, the ultra-wideband from 20MHz to 8GHz is divided into several overlapping sub-bands, and adjacent sub-bands can provide a smooth gain transition at both low and high frequencies, without the bandwidth gaps or deep dips common in traditional segmented antennas.

[0062] Secondly, the equidistant ratio of 1.4-1.6 achieves the optimal balance between coupling strength and isolation. If the length difference is too small, the coupling capacitance at the high-frequency end increases significantly, and the array is prone to crosstalk peaks and standing wave fluctuations; if the difference is too large, it will lead to insufficient subband connection and a drop in the gain curve. By controlling the ratio within this narrow range, adjacent conductors maintain the necessary near-field energy coupling to ensure the continuity of low-frequency resonance, while maintaining an isolation of >10dB in the high-frequency region to suppress crosstalk and mode tilt. At the same time, the equidistant gradient allows the current distribution to change gradually along the array, the main lobe of the radiation pattern to shift smoothly with frequency, and the input impedance curve to maintain a good match below -10dB throughout the entire broadband.

[0063] In any of the above embodiments, all receiving conductors 301 are connected to the wide end of the absorber 2 via horizontal trace conductors 5, which are used to feed the signals captured by the receiver array 3 into the feed point 4 via the absorber 2.

[0064] In this embodiment, from an electrical topology perspective, the horizontal traces provide transmission paths of nearly identical equivalent lengths for each receiving conductor 301. This ensures that signal currents excited by different frequency bands have near-synchronous time delays and phases when they reach the absorber 2, avoiding phase cancellation or synthesis distortion caused by path differences. Secondly, the horizontal traces use the same copper foil material as the receiving conductors 301, a uniform linewidth of 0.5mm, and a fixed length of approximately 11.7mm. This maintains low distributed inductance and parasitic capacitance across the entire bandwidth of 20MHz-8GHz, thereby minimizing transmission loss and maintaining good characteristic impedance continuity.

[0065] The horizontal trace conductor 5 effectively forms a broadband collector bus at the bottom of the array: the electromagnetic energy captured by the receivers on the left and right sides within their respective frequency bands is uniformly fed into the wide end of absorber 2 via the horizontal trace. Due to the tapered impedance characteristics of the trapezoidal structure of absorber 2, the multi-frequency signals output from the horizontal trace to absorber 2 can immediately achieve standing wave suppression and reflection absorption, avoiding the generation of new standing wave peaks and valleys at the conductor convergence point. Simultaneously, the horizontal bus structure confines the distance between the receivers and absorber 2 to a single PCB plane, reducing the number of vias for cross-layer interconnection, lowering vertical parasitic parameters, and further improving signal integrity at high frequencies (especially in the GHz to 8 GHz range). The combined effect is that receiver array 3 achieves in-phase convergence of receiving gain for signals in different frequency bands, low-loss transmission, and integrated impedance matching, providing support for the antenna to obtain a flat gain curve and low VSWR in the ultra-wideband range.

[0066] In any of the above embodiments, the size parameters of the absorber 2 are set according to a preset frequency band range.

[0067] The absorber 2 has a width ratio between its narrow end and its wide end, and the width ratio ranges from 0.1 to 0.2.

[0068] The larger width end of the absorber 2 has a length-to-width ratio along the extension direction, and the length-to-width ratio ranges from 150 to 200.

[0069] In this embodiment, the absorber 2 is designed as a longitudinal trapezoidal non-uniform transmission line, and its dimensions at both ends are geometrically controlled to simultaneously perform three key functions: impedance gradient, standing wave suppression, and bandwidth widening across the entire 20MHz–8GHz wideband. Specifically, the wide end of the absorber 2 is connected to the horizontal trace and feed point 4, responsible for converging multi-frequency signals from the receiver array 3; the narrow end gradually shrinks to 10%–20% of the wide end (width ratio 0.1–0.2), and the lateral gradient from the horn to the tip smoothly transitions the equivalent characteristic impedance from tens of ohms to hundreds of ohms. The reflected waves at the high-frequency end are continuously absorbed in the trapezoid without forming standing wave peaks and valleys at the convergence point, thereby keeping the VSWR below 2:1 across the wideband and significantly reducing high-frequency spike noise.

[0070] Meanwhile, setting the total length of absorber 2 to 150–200 times its width at the wide end provides ample electrical travel, with an aspect ratio range of 150–200. For low-frequency signals, a conductor several hundred millimeters long is equivalent to a progressively loaded λ / 4 transmission line, generating significant inductive reactance in the 20MHz range to compensate for insufficient radiation current at the low-frequency end. For mid-to-high-frequency signals, the same conductor exhibits multi-point resonance in the longitudinal direction, with energy of different frequencies being absorbed or guided at different length segments, effectively dispersing single-point resonance peaks. This long and tapering geometric configuration thus achieves the triple objectives of low-frequency resonance enhancement, high-frequency reflection absorption, and mid-section impedance smoothing.

[0071] Combining the symmetrical arrangement of the front and back, absorber 2 provides progressive matching in the longitudinal direction, forms a common-mode current cancellation channel in the thickness direction, and ensures current collection efficiency by using a wide end with the same width as the left and right horizontal traces in the lateral direction. With three-dimensional collaboration, the high-sensitivity ultra-wideband receiving antenna can achieve 400:1 bandwidth coverage on a compact PCB, with a flat output curve, low VSWR, continuous gain, and stable radiation pattern, meeting the stringent requirements of "single-unit full-band" receiving performance in scenarios such as motion monitoring and spectrum analysis.

[0072] In any of the above embodiments, the receiver conductor with the largest length value in a receiver array 3 is connected to a patch structure 7 through an edge trace conductor 6; the edge trace conductor 6 extends along the front edge of the substrate 1, and the patch structure 7 is located on one side of the absorber 2.

[0073] In this embodiment, in each receiver array 3, the longest receiving conductor 301, which is the most lateral and best at low-frequency resonance, is led out through an edge trace conductor 6 and connected to the patch structure 7 located on one side of the absorber 2. The edge trace conductor 6 extends along the outermost edge of the front of the substrate 1, which effectively lengthens the electrical length of the receiving path without occupying the central space inside the array. The long conductor itself is already sensitive to low-frequency signals, and with the additional physical travel provided by the edge trace, its resonant frequency is further lowered, thereby significantly improving the receiving efficiency in the 20MHz to approximately 100MHz range.

[0074] The patch structure 7, connected to the end of the trace, has a much larger area than a conventional microstrip conductor, essentially acting as a planar capacitor at the end of a long conductor. Strong distributed capacitive coupling is formed between the incident low-frequency electromagnetic wave and the patch, causing current to concentrate around the patch. This effectively absorbs low-frequency signal energy and injects it into the array bus along the edge trace. Because the patch is located on one side of the absorber 2 and connected to the array body across the edge trace, maintaining sufficient spatial distance from other receiving conductors 301, this "local electrical extension + lateral loading" does not disrupt the high-frequency current distribution in the array's central region and avoids parasitic coupling or pattern distortion in the mid-to-high frequency bands.

[0075] In any of the above embodiments, there is a frequency ratio between the highest and lowest operating frequencies within the preset frequency band range, and the value of the frequency ratio ranges from 305 to 450.

[0076] In this embodiment, using a frequency ratio of 305–450 MHz as the design benchmark, the proportionally sized sequence of receiver array 3 and the trapezoidal impedance gradient curve of absorber 2 jointly determine the "lowest resonant f_L" and the "highest effective resonant f_H". As long as the length of the array endpoints and the narrow-to-wide ratio of absorber 2 satisfy the wavelength mapping corresponding to this ratio, the three-segment combination of array-absorber 2-feed point 4 can maintain a VSWR of less than 2:1 across the entire band, achieving seamless reception from longwave to microwave. Bandwidths exceeding 300 times are prone to segment gain drops. By constraining the overall bandwidth to 305–450 MHz, rather than higher or lower, within feasible geometric parameters such as patch loading, proportional spacing, and trapezoidal width ratio, the low-end gain can be maximized while avoiding a sharp increase in loss at the high end due to excessive structural inductance, resulting in a relatively flat gain curve.

[0077] In any of the above embodiments, the number of receiving conductors 301 in the two sets of receiver arrays 3 is set according to a preset frequency band range and in combination with the geometric series coefficients of the length of the receiving conductors 301.

[0078] In this embodiment, the lowest and highest frequency points that must be covered are first determined. Then, the two outermost receiving conductors 301 are designed as the longest and shortest conductors, respectively, capable of generating main resonance near these two extreme frequency points. Based on this, conductors are arranged sequentially from one end to the other in a uniform length ratio, increasing (or decreasing) until the other end is reached. No skipping or omissions are made during this process. Each additional conductor represents the insertion of a new resonant segment into the frequency spectrum, until the space between the lowest and highest frequencies is filled with these segments, resulting in the final number of conductors in the array. Through this "extreme point first, smooth ratio connection" generation strategy, the array exhibits a continuous and uniform resonant ladder in its electromagnetic response: short conductors receive high frequencies, long conductors receive low frequencies, and the frequency bandwidths of adjacent conductors partially overlap without excessive overlap. This avoids "black holes" with no gain in certain frequency ranges, and also prevents strong coupling distortion at high frequencies due to excessive conductor density. More importantly, the left and right arrays are mirrored with the exact same number and length sequence, forming a dual symmetry of geometry and current with the central absorber 2 as the axis of symmetry. This ensures that the antenna's radiation field is balanced across the entire lateral direction, and the main lobe of the radiation pattern will not be skewed due to structural imbalance. This adaptive generation method for the number of arrays also brings significant engineering convenience: if designers extend the frequency band to lower or higher frequencies, they only need to reset the extreme conductor lengths and continue arranging them at the same ratio. The number of array arrays automatically increases or decreases as needed. CAD modeling, PCB etching, and subsequent debugging all maintain the same template logic, greatly simplifying new version iterations and cost control.

[0079] Specifically, the number of receiving conductors 301 is determined by the following formula:

[0080]

[0081] In the formula, N is the number of receiving conductors 301 in the receiver array 3; k is the length scaling factor of the receiving conductors 301, which ranges from 1.3 to 1.7; f L The lowest operating frequency; f H This is the highest operating frequency. When the corresponding frequency band covers 20MHz to 8000MHz, the value of N is in the range of 8 to 16, preferably 11.

[0082] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0083] The above embodiments are merely descriptions of preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A high-sensitivity ultra-wideband receiving antenna, characterized in that, include: Base; The absorber is formed on the front and back sides of the substrate by copper etching; Along one extending direction, at least a portion of the width of each absorber gradually narrows to perform standing wave suppression and impedance matching for multiple frequency band signals within a preset frequency band range; A receiver array is formed on the front side of the substrate by copper etching. Two receiver arrays are arranged symmetrically on the front side of the substrate with the absorber as the axis of symmetry. Each receiver array includes multiple receiving conductors, all of which are arranged sequentially along a direction perpendicular to the extension direction. The lengths of each receiving conductor along the extension direction are distributed in a geometric sequence to segmentally cover the signal reception range of different frequency bands within the preset frequency band. The receiving conductor with the longest length in each receiver array is located on the side furthest from the absorber. All receiving conductors are connected to the wider end of the absorber via horizontal traces. Feed points are provided on the substrate and are respectively connected to the wider end of the absorber.

2. The high-sensitivity ultra-wideband receiving antenna according to claim 1, characterized in that, The absorber is located on the central axis of the front and back sides of the substrate.

3. The high-sensitivity ultra-wideband receiving antenna according to claim 2, characterized in that, Within the same receiver array, adjacent receiver conductors are provided with equal, predetermined gaps. The preset gap ranges from 0.4mm to 0.5mm.

4. The high-sensitivity ultra-wideband receiving antenna according to claim 2, characterized in that, With the absorber as the axis of symmetry, the length ratio between the receiving conductors in symmetrical positions is a first preset value; The first preset value ranges from 1.1 to 1.

3.

5. The high-sensitivity ultra-wideband receiving antenna according to claim 2, characterized in that, Within the same receiver array, the length ratio between adjacent receiver conductors is a second preset value; The second preset value ranges from 1.4 to 1.

6.

6. The high-sensitivity ultra-wideband receiving antenna according to claim 2, characterized in that, The horizontal trace conductor is used to feed the signals captured by the receiver array into the feed point.

7. The high-sensitivity ultra-wideband receiving antenna according to claim 1, characterized in that, The size parameters of the absorber are set according to the preset frequency band range; The absorber has a width ratio between its narrow end and wide end, and the width ratio ranges from 0.1 to 0.

2. The absorber has a length-to-width ratio at the larger end of its length and width along the extending direction, and the length-to-width ratio ranges from 150 to 200.

8. The high-sensitivity ultra-wideband receiving antenna according to claim 7, characterized in that, The receiver conductor with the longest length in the receiver array is connected to a patch structure via an edge trace conductor; the edge trace conductor extends along the front edge of the substrate, and the patch structure is located on one side of the absorber.

9. The high-sensitivity ultra-wideband receiving antenna according to any one of claims 1-8, characterized in that, There is a frequency ratio between the highest and lowest operating frequencies within the preset frequency band range, and the value of the frequency ratio ranges from 305 to 450.

10. The high-sensitivity ultra-wideband receiving antenna according to claim 9, characterized in that, The number of receiving conductors in each of the aforementioned receiver arrays ranges from 8 to 16.

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