Terminal antenna and high isolation antenna system
A terminal antenna includes a first excitation part and a first radiation part, and the first excitation part is disposed at a middle location of the first radiation part. A common-mode feed is disposed on the first excitation part, and the common-mode feed is disposed between the first radiation part and the first excitation part. The common-mode feed is one or two feeds disposed between the first excitation part and the first radiation part.
1 . An electronic device, wherein the electronic device comprises a terminal antenna, the terminal antenna comprises a first antenna, and the first antenna comprises:
a first excitation part;
a first radiation part, wherein the first excitation part is disposed at a middle location of the first radiation part, the first excitation part is configured to excite the first radiation part to work in an N-time wavelength mode for radiation, N is a positive integer larger than 1, a plurality of current reverse points are distributed on the first radiation part, and one of the plurality of current reverse points is at the middle location of the first radiation part; and
a common-mode feed disposed between the first radiation part and the first excitation part, wherein the common-mode feed comprises one or two feeds disposed between the first excitation part and the first radiation part.
2 . The electronic device according to claim 1 , wherein the first excitation part is configured to generate an electric field between the first excitation part and the first radiation part under excitation of the common-mode feed, and the electric field excites the first radiation part for radiation.
3 . The electronic device according to claim 1 , wherein the first antenna comprising the first excitation part and the first radiation part is an axisymmetric structure, and an axis of symmetry of the axisymmetric structure is a perpendicular bisector of a radiator of the first radiation part.
4 . The electronic device according to claim 1 , wherein;
the middle location of the first radiation part is a point with a large eigenmode electric field at an N-time wavelength of the first radiation part.
5 . The electronic device according to claim 1 , wherein the common-mode feed is a low-impedance feed, and port impedance of the low-impedance feed is less than 100 ohms.
6 . The electronic device according to claim 1 , wherein:
the common-mode feed comprises two feeds;
the first excitation part comprises two inverted L-shaped radiators that are not connected to each other; and
one arm of each of the two inverted L-shaped radiators is connected to the first radiation part by using a corresponding feed of the two feeds, and ends of the two inverted L-shaped radiators away from the corresponding feed are away from each other.
7 . The electronic device according to claim 1 , wherein:
a coupling radiator is disposed on the first excitation part, the coupling radiator is disposed between the common-mode feed and the first radiation part, the coupling radiator is connected to the first excitation part by using the common-mode feed, and the coupling radiator is coupled to the first radiation part through coupling by using a slot between the coupling radiator and the first radiation part.
8 . The electronic device according to claim 7 , wherein:
the common-mode feed comprises two feeds;
the first excitation part comprises two inverted L-shaped radiators that are not connected to each other; and
one arm of each of the two inverted L-shaped radiators is connected to the coupling radiator by using a corresponding feed of the two feeds, and ends of the two inverted L-shaped radiators away from the corresponding feed are away from each other.
9 . The electronic device according to claim 1 , wherein the first radiation part comprises any one of the following:
a dipole antenna, a symmetric square loop antenna, a symmetric circular loop antenna, or a symmetric polygon antenna.
10 . The electronic device according to claim 1 , wherein:
the terminal antenna further comprises a second antenna, a differential-mode feed is disposed on the second antenna, and the second antenna comprises a second radiation part;
the differential-mode feed of the second antenna is disposed at a middle location of the second radiation part, and is parallel to the common-mode feed of the first antenna; and
the first radiation part is the second radiation part, or the first radiation part and the second radiation part are two different radiation parts.
11 . The electronic device according to claim 10 , wherein a current at the middle location of the second radiation part of the second antenna is not reversed.
12 . The electronic device according to claim 11 , wherein the first radiation part and the second radiation part are two different radiation parts;
the first antenna and the second antenna are not connected to each other, and the first antenna operates in the N-time wavelength mode; and
the second antenna operates in the N-time wavelength mode, or the second antenna operates in another mode different from the N-time wavelength mode.
13 . The electronic device according to claim 10 , wherein:
the first radiation part is the second radiation part; and
both the first antenna and the second antenna operate in the N-time wavelength mode.
14 . The electronic device according to claim 10 , wherein the second radiation part of the second antenna is a dipole antenna.
15 . The electronic device according to claim 10 , wherein:
a second excitation part is further disposed on the second antenna, and the second excitation part is disposed at the middle location of the second radiation part;
the second excitation part comprises a U-shaped structure radiator, two ends of the U-shaped structure radiator are separately connected to the second radiation part, and a differential-mode feed connected in series is disposed at the bottom of the U-shaped structure radiator; or
the second excitation part comprises two U-shaped structure radiators, the two U-shaped structure radiators are not connected to each other and have openings in a same direction, one feed is disposed on each of ends of the two U-shaped structure radiators close to each other, and is connected to the second radiation part, ends of the two U-shaped structure radiators away from each other are separately connected to the second radiation part directly, and feeds on the two U-shaped structure radiators are separately configured to feed an equal-amplitude phase-inverted differential-mode feeding signal.
16 . The electronic device according to claim 10 , wherein:
a second excitation part is further disposed on the second antenna, the second excitation part is disposed at the middle location of the second radiation part, and the second excitation part and the second radiation part are not connected to each other;
the second excitation part comprises an annular structure radiator, and a differential-mode feed is connected in series on the annular structure radiator; or
the second excitation part comprises two annular structure radiators, the two annular structure radiators are disposed axisymmetrically, two feeds are respectively disposed on sides of the two annular structure radiators close to each other, and the two feeds are separately configured to feed an equal-amplitude phase-inverted differential-mode feeding signal.
17 . The electronic device according to claim 15 , wherein when the second antenna operates, the second antenna operates in a 0.5*M-time wavelength mode, and M is an odd number.
18 . The electronic device according to claim 16 , wherein when the second antenna operates, the second antenna operates in a 0.5*M-time wavelength mode, and M is an odd number.
19 . An electronic device, wherein the electronic device comprises a terminal antenna, and the terminal antenna comprises:
a first excitation part;
a first radiation part, wherein a radiator of the first excitation part comprises two parts, the two parts are respectively disposed at two ends of the first radiation part, the first excitation part is configured to excite the first radiation part to work in an N-time wavelength mode for radiation, N is a positive integer larger than 1, a plurality of current reverse points are distributed on the first radiation part, and one of the plurality of current reverse points is at a middle location of the first radiation part; and
common-mode feeds respectively disposed on the two parts of the radiator of the first excitation part, and the common-mode feeds comprise two feeds disposed between the first excitation part and the first radiation part.
20 . The electronic device according to claim 19 , wherein the radiator of the first excitation part is an inverted L-shaped structure or a vertical structure.