US-12627021-B2 - Base station antenna

US12627021B2US 12627021 B2US12627021 B2US 12627021B2US-12627021-B2

Abstract

A base station antenna includes a feed network, a cable and an adapter structure. The feed network includes a cavity, and an internal structure in the cavity. The adapter structure includes a first transmission line. A first end of the first transmission line is electrically connected to the internal structure. A second end of the first transmission is electrically connected to the cable. The first transmission line is configured to transmit a radio frequency signal. The first transmission line is at least partially located outside the cavity.

Inventors

Chunliang XU
Jiejun Zhou
Xinming Liu
WEI KANG

Assignees

HUAWEI TECHNOLOGIES CO., LTD.

Dates

Publication Date: 20260512
Application Date: 20230629

Claims (20)

1 . A base station antenna, comprising a feed network, a cable, and an adapter structure, wherein the feed network comprises a cavity and an internal structure located in the cavity, the adapter structure comprises a first transmission line and a second transmission line, one end of the first transmission line is electrically connected to one end of the second transmission line, the other end of the first transmission is electrically connected to the cable; wherein the first transmission line is completely located outside the cavity, one end of the second transmission line is connected to the first transmission line, and the other end of the second transmission line extends into the cavity and is connected to the internal structure, the first transmission line and the second transmission line are configured to transmit a radio frequency signal; a transmission line structure of the first transmission line is a suspended strip line, a microstrip, or a strip line; a transmission line structure of the second transmission line is a suspended strip line, a microstrip, or a strip line; the adapter structure further comprises a housing, the housing covers the first transmission line.
2 . The base station antenna according to claim 1 , wherein the first transmission line and the second transmission line use a same transmission line structure.
3 . The base station antenna according to claim 1 , wherein the first transmission line and the second transmission line use different transmission line structures.
4 . The base station antenna according to claim 1 , wherein the feed network comprises a phase shifter and a power divider, and the power divider is electrically connected to the phase shifter.
5 . The base station antenna according to claim 1 , wherein and the suspended strip line comprises a metal strip.
6 . The base station antenna according to claim 5 , wherein the suspended strip line further comprises a metal cavity and a dielectric substrate, the dielectric substrate is suspended in the metal cavity, the metal strip is fixedly connected to the dielectric substrate, the metal cavity comprises two metal side walls that are disposed opposite to each other, recesses are disposed on both the metal side walls, openings of the recesses face an inner side of the metal cavity, and the dielectric substrate is embedded in the two recesses.
7 . The base station antenna according to claim 6 , wherein the suspended strip line comprises two of the metal strips, and the two metal strips are oppositely located on two sides of the dielectric substrate.
8 . The base station antenna according to claim 1 , wherein the strip line comprises a dielectric and a conductor strip disposed in the middle of the dielectric, the dielectric is disposed between two conductive planes, and the two conductive planes are both grounded.
9 . The base station antenna according to claim 1 , wherein the first transmission line is the microstrip, the microstrip comprises a dielectric substrate and a metal strip, and the metal strip is fixedly connected to the dielectric substrate.
10 . The base station antenna according to claim 1 , wherein the feed network is electrically connected to an antenna connector through the cable.
11 . The base station antenna according to claim 1 , wherein the second transmission line includes a first segment and a second segment, one end of the first segment is connected to the internal structure, the other end of the first segment is connected to the second segment, the one end of the second segment is connected to the first segment, the other end of the second segment is connected to the first transmission line.
12 . The base station antenna according to claim 11 , wherein the second transmission line is L-shaped.
13 . The base station antenna according to claim 1 , wherein the housing includes a top plate that is opposite to an end cover of the cavity and two side plates that are separately located on two sides of the top plate, the two side plates are disposed opposite in which one end is fixedly connected to the top plate and the other end is fixedly connected to the end cover.
14 . The base station antenna according to claim 13 , wherein the housing is made of a metal material.
15 . The base station antenna according to claim 1 , wherein an end cover of the cavity is provided with a through hole, wherein the internal structure of the feed network is connected to the second transmission line through the through hole.
16 . A base station, comprising a base station antenna and a feeder connected to the base station antenna, wherein the base station antenna comprises: a feed network, a cable, and an adapter structure, wherein the feed network comprises a cavity and an internal structure located in the cavity, the adapter structure comprises a first transmission line and a second transmission line, one end of the first transmission line is electrically connected to one end of the second transmission line, the other end of the first transmission is electrically connected to the cable; wherein the first transmission line is completely located outside the cavity, one end of the second transmission line is connected to the first transmission line, and the other end of the second transmission line extends into the cavity and is connected to the internal structure, the first transmission line and the second transmission line are configured to transmit a radio frequency signal; the transmission line structure of the first transmission line is a suspended strip line, a microstrip, or a strip line; the transmission line structure of the second transmission line is a suspended strip line, a microstrip, or a strip line; the adapter structure further comprises a housing, the housing covers the first transmission line.
17 . The base station according to claim 16 , wherein the first transmission line and the second transmission line use a same transmission line structure.
18 . The base station according to claim 16 , wherein the first transmission line and the second transmission line use different transmission line structures.
19 . The base station according to claim 16 , wherein the feed network comprises a phase shifter and a power divider, and the power divider is electrically connected to the phase shifter.
20 . The base station according to claim 16 , wherein the suspended strip line comprises a metal strip.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a continuation of International Application No. PCT/CN2020/141829, filed on Dec. 30, 2020, the disclosure of which is hereby incorporated by reference in its entirety. TECHNICAL FIELD This application relates to the field of antenna technologies, and in particular, to a base station antenna. BACKGROUND A base station antenna includes components such as a cable, a feed network, and a radiation unit. Each module is connected through media. As a mobile communication system develops towards a multi-frequency multi-system, the base station antenna also needs multi-frequency multi-polarization. However, a multi-frequency base station antenna has many frequency bands, resulting in a very complex connection of the feed network. Consequently, discontinuous transmission of a radio frequency signal is increased, and electrical performance of the base station antenna is affected. SUMMARY One or more embodiments of this application provide a base station antenna. A feed network in the base station antenna is connected to a cable by an adapter structure, and characteristic impedance of a transmission line of the adapter structure is adjusted to match impedance of the cable, to expand matching range of the feed network and improve continuity of radio frequency signal transmission, thereby improving electrical performance of the antenna base station. In some embodiments, a base station antenna includes a feed network, a cable, and an adapter structure. The feed network includes a cavity and an internal structure located in the cavity. The adapter structure includes a first transmission line. One end of the first transmission line is electrically connected to the internal structure, and the other end of the first transmission line is electrically connected to the cable. The first transmission line is configured to transmit a radio frequency signal. The first transmission line is at least partially located outside the cavity. In some embodiments, characteristic impedance of the first transmission line is easy to adjust, and an internal loss of the radio frequency signal in the first transmission line is less than the loss of the radio frequency signal in the cable. The feed network and the cable are transferred through the first transmission line, and characteristic impedance of the first transmission line is adjusted to match impedance of the cable, to expand matching range of the feed network. In some approaches, the cable is directly connected to the feed network. However, in this application, a part of the cable is replaced with first transmission line. Because a loss caused by the first transmission line to the radio frequency signal is lower than a loss caused by the cable of a same length, impedance of a transmission line of the radio frequency signal is reduced, a loss is reduced, and an antenna gain is improved. In some embodiments, one end of the first transmission line extends into the cavity to connect to the internal structure, to expand matching range of the feed network and reduce assembly and design difficulties. In some embodiments, the first transmission line is completely located outside the cavity. The adapter structure further includes a second transmission line. One end of the second transmission line is connected to the first transmission line, and the other end of the second transmission line extends into the cavity to connect to the internal structure. In some embodiments, the second transmission line is used for transition, to enable the first transmission line to be more flexibly connected to the internal structure of the feed network. In addition, the characteristic impedances of the first transmission line and the second transmission line may be separately designed, to match impedance of the cable, thereby improving design flexibility and expanding matching range of the feed network. In some embodiments, the first transmission line and the second transmission line use a same transmission line structure, to enable the second transmission line and the first transmission line to be connected in a simple manner, and reduce assembly difficulty. The transmission line structure is a suspended strip line, a microstrip, or a strip line. In some embodiments, the first transmission line and the second transmission line use different transmission line structures, to enable different transmission modes to be implemented, thereby achieving an objective of switching a radio frequency transmission mode. The transmission line structure is a suspended strip line, a microstrip, or a strip line. In some embodiments, the feed network includes a phase shifter and a power divider, and the power divider is electrically connected to the phase shifter. The power divider receives a radio frequency signal from the cable through a phase-shift network of the phase shifter, then divides the radio frequency signal into a plurality of channels of output signals based on