CN-121983788-A - Single-plane broadband quasi-isotropic microstrip antenna

CN121983788ACN 121983788 ACN121983788 ACN 121983788ACN-121983788-A

Abstract

The invention discloses a single-plane broadband quasi-isotropic microstrip antenna which adopts a single-plane structure and comprises a dielectric substrate and an antenna radiation unit attached to the dielectric substrate, wherein the antenna radiation unit comprises a folded dipole and a feed structure, the folded dipole is formed by rotating and bending a half-wave dipole microstrip line and comprises a front branch of the folded dipole and a tail branch of the folded dipole which are connected, the tail branch of the folded dipole is vertically upwards relative to the dielectric substrate, and the feed structure comprises an excitation port arranged at the edge of the dielectric substrate and two mutually symmetrical microstrip feed lines. The invention realizes good impedance matching and quasi-isotropic radiation characteristics in a wide frequency band, has the advantages of simple structure, convenient processing, low cost, easy integration and the like, and is suitable for the fields of the Internet of things, wireless sensors and the like.

Inventors

WAN SHAOPENG
MEI MINGYANG
CHEN WENHONG

Assignees

华东交通大学

Dates

Publication Date: 20260505
Application Date: 20260309

Claims (10)

1. A uniplanar broadband quasi-isotropic microstrip antenna comprising: The antenna comprises a dielectric substrate, an antenna radiation unit, a first antenna and a second antenna, wherein the antenna radiation unit is attached to the dielectric substrate and comprises a folded dipole and a feed structure; The folded dipole is formed by rotating and bending a half-wave dipole microstrip line, and comprises a front branch of the folded dipole and a tail branch of the folded dipole which are connected, wherein the tail branch of the folded dipole is vertically upwards relative to the medium substrate; The feeding structure comprises an excitation port arranged at the edge of a medium substrate and two mutually symmetrical microstrip feed lines, wherein the excitation port is connected with the two microstrip feed lines, each microstrip feed line comprises a rectangular branch, a trapezoid gradual change branch with an interdigital structure and a triangle branch, the rectangular branch is connected with the excitation port, the trapezoid gradual change branch is connected between the rectangular branch and the triangle branch, and the triangle branch is connected with the front branch of the folded dipole.
2. The uniplanar broadband quasi-isotropic microstrip antenna according to claim 1, wherein said folded dipole is rotated to form an obtuse angle of 90 ° to 180 °.
3. The uniplanar broadband quasi-isotropic microstrip antenna according to claim 1, wherein said folded dipole has a total length of at least two-fifths of an operating wavelength, a width of at least one percent of the operating wavelength, and a bend position spaced from a center of the folded dipole by at least one-twelfth of the operating wavelength.
4. The uniplanar broadband quasi-isotropic microstrip antenna according to claim 1, wherein said folded dipole front stub length is at least eight-tenth of said folded dipole tail stub length, said folded dipole tail stub and folded dipole front stub forming a pair of opposing currents and a current approximately orthogonal thereto, the radiation patterns of which are complementary to each other, thereby achieving quasi-isotropic radiation.
5. The uniplanar broadband quasi-isotropic microstrip antenna according to claim 1, wherein said rectangular stubs each have a length and width of at least one fourth percent of the operating wavelength for convenient feeding.
6. The uniplanar broadband quasi-isotropic microstrip antenna according to claim 1, wherein said trapezoid tapered stub is right trapezoid shaped, the length of the short side of said trapezoid tapered stub is consistent with the width of the rectangular stub, and the length of the long side of said trapezoid tapered stub is at least one tenth of the operating wavelength for widening the operating bandwidth of the antenna.
7. The uniplanar broadband quasi-isotropic microstrip antenna according to claim 1, wherein a first side of said triangular stub coincides with a front stub of a folded dipole and a second side of said triangular stub coincides with a long side of said trapezoid tapered stub for effecting transfer of feed energy to the antenna.
8. The uniplanar broadband quasi-isotropic microstrip antenna of claim 1, wherein the inter-digitated structure in the trapezoid tapered branch is trapezoid in shape, the slit width of the inter-digitated structure is at least two thousandths of the operating wavelength, the length of the long side is at least forty-th of the operating wavelength, and the height is at least twenty-th of the operating wavelength, and the inter-digitated structure presents capacitive impedance characteristics for adjusting impedance matching of the antenna.
9. A uniplanar broadband quasi-isotropic microstrip antenna according to claim 1, wherein said folded dipole arms are rotated upward by an angle of 17.5 °.
10. The uniplanar broadband quasi-isotropic microstrip antenna of claim 1, wherein said dielectric substrate is polytetrafluoroethylene.

Description

Single-plane broadband quasi-isotropic microstrip antenna Technical Field The invention relates to the field of antennas, in particular to a single-plane broadband quasi-isotropic microstrip antenna. Background With the rapid development of wireless communication systems, the internet of things, wireless sensor networks and the like are widely concerned and researched, and the internet of things has become a current hot research direction. In order to adapt to the diversity of communication protocols such as the internet of things and meet the demands of people for higher-speed and more stable connection of the internet of things equipment, it is highly desirable to develop an antenna which has broadband characteristics and can effectively receive electromagnetic wave signals from all directions, namely a broadband quasi-isotropic antenna. The broadband quasi-isotropic antenna has the characteristics of full space coverage of radiation signals and relatively consistent intensity of the radiation signals in the whole space, can have relatively stable performance in a wider frequency range, can realize high-speed data transmission and wide coverage, meets the requirements of modern Internet of things equipment on high speed and high stability, and has important research value. At present, most quasi-isotropic antennas are in a single-frequency point working mode, and the research of broadband quasi-isotropic antennas is less. Changjiang Deng et al in 'A Wideband Isotropic RADIATED PLANAR ANTENNA Using Sequential Rotated L-Shaped Monopoles' adopt four monopoles to sequentially rotate and arrange, so that 20.8% of-10 dB impedance bandwidth and 6.8% of 6dB radiation isotropy bandwidth are realized, but the antenna needs to excite the four monopoles by adopting four paths of signals with the same amplitude and orthogonal phases of 0 DEG, 90 DEG, 180 DEG and 270 DEG, and has a complex structure. Based on the crossed electric dipoles in orthogonal arrangement in "Planar Single-Layer Wideband Electrically Small Quasi-Isotropic Antenna Characterized by Filtering Response" by Yang Wang et al, quasi-isotropic coverage is achieved by introducing a C-shaped near-field resonant parasitic (NFRP) element, and two radiation zeros are introduced to enhance frequency selectivity, finally achieving a-10 dB impedance bandwidth of 14.2% and a 6dB omnidirectional bandwidth of 7%, but its multi-planar structure is not conducive to integration. Therefore, there is a need for a single-plane broadband quasi-isotropic antenna that is simple in structure and easy to integrate. Disclosure of Invention The invention aims to solve the problems of complex structure, difficult integration and the like of the traditional broadband quasi-isotropic antenna, and provides a single-plane broadband quasi-isotropic microstrip antenna with a simple structure. The invention is realized by the following technical scheme: a single plane broadband quasi-isotropic microstrip antenna comprising: The antenna comprises a dielectric substrate, an antenna radiation unit, a first antenna and a second antenna, wherein the antenna radiation unit is attached to the dielectric substrate and comprises a folded dipole and a feed structure; The folded dipole is formed by rotating and bending a half-wave dipole microstrip line, and comprises a front branch of the folded dipole and a tail branch of the folded dipole which are connected, wherein the tail branch of the folded dipole is vertically upwards relative to the medium substrate; The feeding structure comprises an excitation port arranged at the edge of a medium substrate and two mutually symmetrical microstrip feed lines, wherein the excitation port is connected with the two microstrip feed lines, each microstrip feed line comprises a rectangular branch, a trapezoid gradual change branch with an interdigital structure and a triangle branch, the rectangular branch is connected with the excitation port, the trapezoid gradual change branch is connected between the rectangular branch and the triangle branch, and the triangle branch is connected with the front branch of the folded dipole. Preferably, the thickness of the dielectric substrate layer is 0.5-5mm, and the dielectric substrate with low loss can be selected. The single-plane broadband quasi-isotropic microstrip antenna is characterized in that the folded dipole is formed by rotating and bending a half-wave dipole microstrip line, two arms of the folded dipole are rotated upwards by the same angle, the included angle between the two arms is changed from the original 180 degrees to an obtuse angle (namely between 90 degrees and 180 degrees), on the basis, the two arms are bent upwards at the same time, and the folded dipole can be divided into a front branch of the folded dipole and a tail branch of the folded dipole, wherein the tail branch of the folded dipole is vertically upwards relative to the dielectric substrate. Preferably, the total length of the fol