# US 2014/0152525 A1 · Transmission line and antenna device

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- Number: US 2014/0152525 A1
- Document ID: US20140152525A1
- Status: Published application
- Kind: A1
- Application number: 14/059,091
- Filed: 2013-10-21
- Published: 2014-06-05
- Earliest claimed: 2012-12-03
- Assignees: Hitachi Metals, Ltd.
- Applicants: Hitachi Metals, Ltd.
- Inventors: Naoki Iso; Nobuaki Kitano
- Web page: https://patentgrep.com/patent/US20140152525A1

## CPC

- H01Q 1/50: Structural association of antennas with earthing switches, lead-in devices or lightning protectors
- H01P 3/085: {Triplate lines}
- H01P 3/087: {Suspended triplate lines}
- H01Q 21/0081: {using suspended striplines}
- H01Q 21/08: the units being spaced along or adjacent to a rectilinear path {(waveguide fed H01Q21/0037)}
- H01Q: ANTENNAS, i.e. RADIO AERIALS (radiators or antennas for microwave heating H05B6/72)
- H01P: WAVEGUIDES; RESONATORS, LINES, OR OTHER DEVICES OF THE WAVEGUIDE TYPE (operating at optical frequencies G02B)

## Abstract

A transmission line has a triplate line including a first outer conductor and a second outer conductor disposed in parallel with each other at a predetermined interval, and a central conductor disposed in a space between the first outer conductor and the second outer conductor; and a dielectric spacer interposed between the first and second outer conductors and the central conductor and configured to support the central conductor. The central conductor has a supported portion supported by the dielectric spacer, and first and second high-impedance portions having characteristic impedances higher than a characteristic impedance in the supported portion. The first and second high-impedance portions are disposed on input and output sides, respectively, of the supported portion.

## Claims

### Claim 1

A transmission line comprising:
a triplate line including a pair of outer conductors disposed in parallel with each other at a predetermined interval, and a central conductor disposed in a space between the pair of outer conductors; and
a spacer interposed in the space between the pair of outer conductors and the central conductor, the spacer being made of a dielectric material and configured to support the central conductor,
wherein the central conductor has a supported portion supported by the spacer, and first and second high-impedance portions having characteristic impedances higher than a characteristic impedance in the supported portion, the first and second high-impedance portions being disposed on input and output sides, respectively, of the supported portion.

### Claim 2 (depends on 1)

The transmission line according to claim 1, wherein a line width in the supported portion is greater than line widths in the first and second high-impedance portions.

### Claim 3 (depends on 1)

The transmission line according to claim 1, wherein the spacer has a first spacer member having a plate-like base and a protrusion protruding from the base, and a second spacer member having a fitting hole into which the protrusion is fitted; and
the supported portion is supported by being sandwiched between the base of the first spacer member and the second spacer member, and has a through hole into which the protrusion is inserted.

### Claim 4 (depends on 1)

The transmission line according to claim 1, wherein a relationship represented by the following equation is satisfied:
Z
1
=
(
Z
0

Z
2
+
Z
0
2
)

{
sin
(
4

π
λ

L
1
)
+
cos
(
4

π
λ

L
1
)

tan
(
2

π
λ

L
2
)
}
-
2

Z
0

Z
2

tan


(
2

π
λ

L
2
)
(
Z
0
+
Z
2
)

{
sin


(
4

π
λ

L
1
)
+
cos


(
4

π
λ

L
1
)

tan

(
2

π
λ

L
2
)
}
-
2

tan

(
2

π
λ

L
2
)

Z
0
where Z0 is a characteristic impedance of a main body of the triplate line, Z1 is a characteristic impedance of both the first and second high-impedance portions, Z2 is a characteristic impedance in the supported portion supported by the spacer, L1 is a line length of both the first and second high-impedance portions, and L2 is a line length of the supported portion.

### Claim 5 (depends on 1)

The transmission line according to claim 1, wherein the transmission line is applied to a distributor placed between a transmitting device and a plurality of antenna elements or to a multiplexer placed between the plurality of antenna elements and a receiving device.

### Claim 6 (depends on 1)

An antenna device comprising:
the transmission line according to claim 1; and
an antenna element.