Power distribution network, liquid crystal antenna and communication device

1. A liquid crystal antenna, comprising: a first substrate and a second substrate opposite to each other; a plurality of radiating devices on a side of the first substrate away from the second substrate; a power distribution network comprising a plurality of cascaded power distributors, each of the plurality of cascaded power distributors comprising a first microstrip line, a transmission medium region and a reference electrode, wherein the power distribution network is configured to feed electromagnetic signals to the plurality of radiating devices; a phase shifter comprising a plurality of liquid crystal regions between the first substrate and the second substrate, the reference electrode between the first substrate and the plurality of liquid crystal regions, and a second microstrip line between the second substrate and the plurality of liquid crystal regions, and a second impedance transformer electrically coupled between the first microstrip line and the second microstrip line adjacent to each other, wherein a tangent value of a dielectric loss angle of a transmission medium in the transmission medium region is smaller than a tangent value of a dielectric loss angle of a liquid crystal in the plurality of liquid crystal regions, wherein the transmission medium region of each power distributor is between adjacent liquid crystal regions, and the transmission medium region and a liquid crystal region adjacent to the transmission medium region are separated by a wall, and wherein an orthographic projection of the wall on the second substrate at least partially overlaps with an orthographic projection of the second impedance transformer on the second substrate, and a length and width of the second impedance transformer are associated with a dielectric constant of the wall.

2. The liquid crystal antenna according to claim 1 , wherein the first microstrip line comprises a plurality of sub-microstrip lines with different impedances, and each power distributor further comprises a first impedance transformer electrically coupled between the first microstrip lines with different impedances.

3. The liquid crystal antenna according to claim 1 , wherein the transmission medium in the transmission medium region is air.

4. The liquid crystal antenna according to claim 1 , wherein a width of the first microstrip line satisfies the following formula:

Z

01

=

60

ɛ

e

⁢

⁢

1

⁢

ln

⁡

[

μ

1

w

1

/

h

1

+

1

+

(

2

w

1

/

h

1

)

2

]

where Z 01 represents a characteristic impedance of the first microstrip line, ε e1 represents an effective dielectric constant of the transmission medium in the transmission medium region, μ 1 represents a magnetic permeability of the transmission medium in the transmission medium region, w 1 represents a width of the first microstrip line, and h 1 represents a thickness of the transmission medium region.

5. A liquid crystal antenna, comprising: a first substrate and a second substrate opposite to each other; a plurality of radiating devices on a side of the first substrate away from the second substrate; a power distribution network comprising a plurality of cascaded power distributors, each of the plurality of cascaded power distributors comprising a first microstrip line, a transmission medium region and a reference electrode, wherein the power distribution network is configured to feed electromagnetic signals to the plurality of radiating devices; and a phase shifter comprising: a plurality of liquid crystal regions between the first substrate and the second substrate, the reference electrode between the first substrate and the plurality of liquid crystal regions, and a second microstrip line between the second substrate and the plurality of liquid crystal regions; and a second impedance transformer electrically coupled between the first microstrip line and the second microstrip line adjacent to each other, wherein, respective one of the plurality of liquid crystal regions corresponds to respective one of the plurality of radiating devices, and an orthographic projection of each radiating device on the second substrate at least partially overlaps with an orthographic projection of the corresponding liquid crystal region on the second substrate; the transmission medium region of each power distributor is between adjacent liquid crystal regions, the reference electrode of each power distributor is between the first substrate and the transmission medium region, and the first microstrip line of each power distributor is between the second substrate and the transmission medium region; a tangent value of a dielectric loss angle of a transmission medium in the transmission medium region is smaller than a tangent value of a dielectric loss angle of a liquid crystal in the plurality of liquid crystal regions; the transmission medium region and a liquid crystal region adjacent to the transmission medium region are separated by a wall; and an orthographic projection of the wall on the second substrate at least partially overlaps with an orthographic projection of the second impedance transformer on the second substrate, and a length and width of the second impedance transformer are associated with a dielectric constant of the wall.

6. The liquid crystal antenna according to claim 5 , wherein the wall is made of a frame sealant.

7. The liquid crystal antenna according to claim 5 , wherein a width of the second microstrip line satisfies the following formula:

Z

02

=

60

ɛ

e

⁢

⁢

2

⁢

ln

⁡

[

μ

2

w

2

/

h

2

+

1

+

(

2

w

2

/

h

2

)

2

]

where Z 02 represents a characteristic impedance of the second microstrip line, ε e2 represents an effective dielectric constant of the liquid crystal in the liquid crystal region, μ 2 represents a magnetic permeability of the liquid crystal in the liquid crystal region, w 2 represents a width of the second microstrip line, and h 2 represents a thickness of the liquid crystal region.

8. A communication device comprising the liquid crystal antenna according to claim 5 .