CN-122026054-A - Common-caliber base station antenna with ultra-wide impedance and wave-transparent bandwidth

Abstract

The invention discloses a common-caliber base station antenna with ultra-wide impedance and wave-transparent bandwidth, which comprises a low-frequency antenna, four high-frequency antennas and a rectangular reflection ground, wherein the four high-frequency antennas are respectively arranged at four corner end positions of the low-frequency antenna, and the rectangular reflection ground is arranged at the lowest part of the whole antenna array. The low-frequency antenna is of a double-layer structure, the lower-layer structure comprises four annular radiating arms which are arranged in a central symmetry mode, the annular radiating arms are of an impedance ladder transformation structure, and impedance matching of-14 dB in a 617MHz-960MHz frequency band is achieved through impedance gradual change. The inner side of the annular radiation arm is connected with a plurality of filtering branches, a2 x2 patch array is arranged at the center of the inner side, the upper layer structure comprises a 3*3 patch array which is opposite to the center of the inner side of the annular radiation arm, and the filtering branches and the double-layer patch array form a wave-transmitting structure in a cooperative manner to realize 1710MHz-2690MHz broadband wave transmission.

Inventors

• Yang Menmen
• SHI CHENYANG
• CHEN JIANXIN

Assignees

• 南通大学

Dates

Publication Date

20260512

Application Date

20260327

Claims (8)

1. 1. The common-caliber base station antenna with ultra-wide impedance and wave-transparent bandwidth is characterized by comprising a low-frequency antenna, four high-frequency antennas and a rectangular reflection ground, wherein the four high-frequency antennas are respectively arranged at four corner end positions of the low-frequency antenna, and the rectangular reflection ground is arranged at the lowest part of the whole antenna array and covers the plane range of the whole antenna array; The low-frequency antenna is of a double-layer structure, the lower-layer structure comprises four annular radiating arms which are arranged in a central symmetry mode, the annular radiating arms are of impedance ladder transformation structures, vibrator arms at feeding positions are widest, vibrator arms far away from the feeding positions are gradually narrowed, impedance matching of-14 dB in a 617MHz-960MHz frequency band is achieved through impedance gradual change, the inner side of each annular radiating arm is connected with a plurality of filtering branches, a 2x 2 patch array is arranged at the center of the inner side of each annular radiating arm, the upper-layer structure comprises 3*3 patch arrays which are opposite to the center of the inner side of each annular radiating arm, and the filtering branches and the double-layer patch arrays form a wave-transmitting structure in a cooperative mode to achieve broadband wave transmission of 1710MHz-2690 MHz.
2. 2. The common-caliber base station antenna according to claim 1, wherein a balun is arranged below the junction of the four annular radiating arms in the geometric center of the low-frequency antenna, and the balanced output end of the balun is directly and electrically connected with the feed ends of the four annular radiating arms to realize the conversion from unbalanced feed to balanced feed.
3. 3. The common-caliber base station antenna according to claim 1, wherein the double-layer structure of the low-frequency antenna is printed on the surfaces of the two dielectric substrates respectively.
4. 4. A co-aperture base station antenna as claimed in claim 3, wherein a gap of 4mm to 8mm is left between the two dielectric substrates.
5. 5. The common-caliber base station antenna according to claim 1, wherein each filtering branch is equivalent to an LC parallel resonance, a long side of the branch opposite to the annular radiating arm is equivalent to an inductance, and a distance between the long side and the annular radiating arm is equivalent to a capacitance.
6. 6. A co-aperture base station antenna according to claim 5, wherein four pairs of filtering branches are connected to the inner side of each annular radiating arm, each pair of filtering branches being formed by two L-shaped metal strips connected symmetrically.
7. 7. The common-caliber base station antenna according to claim 1, wherein the 2 x 2 patch array of the lower layer and the 3*3 patch array of the upper layer form a stacked patch loading structure through interlayer capacitive coupling, and form a multistage LC parallel resonant network together with the filtering branches.
8. 8. A co-aperture base station antenna as claimed in claim 2, wherein the four annular radiating arms are symmetrically arranged with respect to the antenna centre as a point of symmetry, in a cross-orthogonal centre, at an angle of 90 ° to each other.

Description

Common-caliber base station antenna with ultra-wide impedance and wave-transparent bandwidth Technical Field The invention relates to the field of microwave and millimeter wave communication, in particular to a wave-transmitting base station antenna with ultra-wide impedance and wave-transmitting bandwidth. Background Early mobile communication (2G/3G/4G age), has few frequency bands and single function. Antennas of different frequency bands in a base station are generally arranged in a discrete mode. With the vigorous development of the fifth generation mobile communication system (5G), the base station antenna is evolving toward multi-mode and multi-band directions. Due to the rapid increase of frequency spectrum resources, exhaustion of base station site resources, popularization of large-scale multiple input multiple output technology and improvement of base station operation cost, the traditional discrete arrangement mode has reached the end, and the common caliber design can effectively solve the problems by integrating antennas of different frequency bands which are originally arranged separately into the same physical caliber. According to different array schemes of high-frequency and low-frequency antennas, the common caliber technology can be divided into four types of parallel, stacked, nested and staggered. The high-frequency antennas and the low-frequency antennas of the side-by-side common-caliber base station antennas are distributed in parallel according to a certain interval, the distance between the high-frequency antennas and the low-frequency antennas is long, the interference between the high-frequency antennas and the low-frequency antennas is relatively small, the whole width of the antennas is large, the space utilization rate is low, and the requirement of miniaturization of the antennas is difficult to meet. The stacked scheme places the high-frequency antennas in a stacked manner, and comprises a low-top-bottom scheme and a low-bottom-top scheme. The low upper and lower parts can cause serious low-frequency scattering interference problems, and the low upper and lower parts can cause problems of overhigh section and the like. The nested scheme is to embed the high-frequency antenna into the low-frequency antenna, and the space utilization rate is greatly improved, but the nested scheme is limited by the frequency ratio of the high-frequency antenna and the low-frequency antenna, so that the design flexibility is poor. The staggered scheme further shortens the space between the high-frequency antenna and the low-frequency antenna on the basis of the side-by-side scheme to improve the space utilization rate and achieve miniaturization, but the low-frequency antenna can shield the high-frequency antenna, so that the interference between the high-frequency antenna and the low-frequency antenna is increased. The staggered scheme is flexible in design and high in array freedom, so that the method becomes the most widely used array scheme in the current common-caliber base station antenna. How to solve the problem of shielding interference of a low-frequency antenna to a high-frequency antenna in an interlaced scheme becomes a research direction of the most promising application prospect of the common-caliber base station antenna. In the existing staggered common-caliber base station antenna, the low-frequency antenna can shield the high-frequency antenna, which generally leads to the deterioration of the radiation pattern of the high-frequency antenna, and the low-frequency antenna is generally designed as a wave-transparent antenna to solve the problem. The common wave-transmitting technology mainly comprises two types, namely, loading a filtering structure on a low-frequency antenna radiation arm, such as an L-shaped filtering branch, a choke coil and the like, and loading a frequency selection surface in the low-frequency antenna radiation arm to realize wave transmission. The first technology loads a filtering structure on a radiation arm of a low-frequency antenna, and the loaded filtering structure can damage the impedance characteristic of the low-frequency antenna and influence the matching of the low-frequency antenna although the wide bandwidth of the transmission band can be realized. The second technology is to load a frequency selection surface in the radiation arm of the low-frequency antenna to transmit waves, the impedance characteristic of the low-frequency antenna is not affected by the frequency selection surface, but the wave transmission capability is limited, and broadband wave transmission is difficult to realize. At most, the prior optimal technology can only realize the impedance bandwidth of 690MHz-960MHz of the low-frequency antenna and the wave-transparent bandwidth of 1710MHz-2690 MHz. However, the market has set higher requirements on the impedance bandwidth of the low-frequency antenna, and the impedance bandwidth is greatly improved from 690MHz to 960MHz