Radio-frequency filter comprising an even mode resonance of a same phase inside the bandwidth and an odd mode resonance of a reverse phase outside the bandwidth
A resonance element according to an embodiment transmits a radio-frequency signal, and includes a first substrate, a second substrate, a first circuit element formed on the first substrate, a second circuit element formed on the second substrate, and a transmission line connecting the first circuit element and the second circuit element, and a peak of even mode resonance in which the first circuit element and the second circuit element resonate in the same phase is within a bandwidth of a transmission signal, and a peak of odd mode resonance in which the first circuit element and the second circuit element resonate in a reverse phase is outside the bandwidth.
1. A resonance element for transmitting a radio-frequency signal, comprising:
a first substrate;
a second substrate;
a first circuit element formed on the first substrate, the first circuit element having a first resonant property;
a second circuit element formed on the second substrate, the second circuit element having a second resonant property; and
a transmission line connecting the first circuit element and the second circuit element,
wherein a peak of even mode resonance in which the first circuit element and the second circuit element resonate in a same phase is within a bandwidth of a transmission signal, and a peak of odd mode resonance in which the first circuit element and the second circuit element resonate in a reverse phase is outside the bandwidth, and
wherein when a central frequency of the transmission signal is represented as f 0 and the bandwidth of the transmission signal is represented as BW, an electrical length φ of the transmission line satisfies one of two limitations identified in the following formula 1,
0
<
ϕ
<
90
-
BW
f
0
·
180
,
90
·
n
+
BW
f
0
·
180
<
ϕ
<
90
·
(
n
+
1
)
-
BW
f
0
·
180
formula
1
(n is a positive integer).
2. A wireless system comprising the resonance element according to claim 1 .
3. The resonance element according to claim 1 ,
wherein the transmission line includes a coaxial cable.
4. The resonance element according to claim 1 , further comprising:
a third substrate,
wherein the transmission line is formed on the third substrate, and the first circuit element and the transmission line, and the second circuit element and the transmission line are physically separated.
5. The resonance element according to claim 1 ,
wherein the transmission line includes a waveguide.
6. The resonance element according to claim 1 ,
wherein the first circuit element and the second circuit element include a superconductor.
7. The resonance element according to claim 1 ,
wherein the transmission line includes a superconductor.
8. A radio-frequency filter comprising:
a first substrate;
a second substrate;
a first resonance element including a first circuit element formed on the first substrate, a second circuit element formed on the second substrate, and a transmission line connecting the first circuit element and the second circuit element, a peak of even mode resonance in which the first circuit element and the second circuit element resonate in a same phase being within a bandwidth of a filter circuit, a peak of odd mode resonance in which the first circuit element and the second circuit element resonate in a reverse phase being outside the bandwidth;
a second resonance element formed on the first substrate and connected to the first resonance element; and
a third resonance element formed on the second substrate and connected to the first resonance element,
wherein when a central frequency of the filter circuit is represented as f 0 , and the bandwidth is represented as BW, an electrical length φ of the transmission line satisfies one of two limitations identified in the following formula 1,
0
<
ϕ
<
90
-
BW
f
0
·
180
,
90
·
n
+
BW
f
0
·
180
<
ϕ
<
90
·
(
n
+
1
)
-
BW
f
0
·
180
formula
1
(n is a positive integer).
9. A resonance element for transmitting a radio-frequency signal, comprising:
a first circuit element group;
a second circuit element group;
a first circuit element belongs to the first circuit element group, the first circuit element having resonant property;
a second circuit element belongs to the second circuit element group, the second circuit element having a first resonant property; and
a transmission line connecting the first circuit element and the second circuit element,
wherein a peak of even mode a second resonance in which the first circuit element and the second circuit element resonate in a same phase is within a bandwidth of a transmission signal, and a peak of odd mode resonance in which the first circuit element and the second circuit element resonate in a reverse phase is outside the bandwidth, and
wherein when a central frequency of the transmission signal is represented as f 0 and the bandwidth of the transmission signal is represented as BW, an electrical length φ of the transmission line satisfies one of two limitations identified in the following formula 1,
0
<
ϕ
<
90
-
BW
f
0
·
180
,
90
·
n
+
BW
f
0
·
180
<
ϕ
<
90
·
(
n
+
1
)
-
BW
f
0
·
180
formula
1
(n is a positive integer).
10. The resonance element according to claim 9 ,
wherein the first circuit element and the second circuit element are cavity resonance elements.