Butler matrix circuit, phased array antenna, front-end module, and wireless communication terminal
[Object] There is provided a Butler matrix circuit that makes it possible to further reduce volume and power consumption and to obtain symmetrical radiation characteristics. [Solution] There is provided a Butler matrix circuit including: four processing-circuit-side terminals; four antenna-side terminals; a first 90° hybrid coupler coupled to a first processing-circuit-side terminal and a second processing-circuit-side terminal; a second 90° hybrid coupler coupled to a third processing-circuit-side terminal and a fourth processing-circuit-side terminal; a third 90° hybrid coupler coupled to a first antenna-side terminal and a third antenna-side terminal; a fourth 90° hybrid coupler coupled to a second antenna-side terminal and a fourth antenna-side terminal; a first 90° delay circuit provided between the first 90° hybrid coupler and the third 90° hybrid coupler; and a second 90° delay circuit provided between the first 90° hybrid coupler and the fourth 90° hybrid coupler.
1. A Butler matrix circuit comprising:
four processing-circuit-side terminals;
four antenna-side terminals;
a first 90° hybrid coupler coupled to a first processing-circuit-side terminal and a second processing-circuit-side terminal;
a second 90° hybrid coupler coupled to a third processing-circuit-side terminal and a fourth processing-circuit-side terminal;
a third 90° hybrid coupler coupled to a first antenna-side terminal and a third antenna-side terminal;
a fourth 90° hybrid coupler coupled to a second antenna-side terminal and a fourth antenna-side terminal;
a first 90° delay circuit provided between the first 90° hybrid coupler and the third 90° hybrid coupler;
a second 90° delay circuit provided between the first 90° hybrid coupler and the fourth 90° hybrid coupler,
the second 90° hybrid coupler being directly coupled to the third and fourth 90° hybrid couplers;
a first 180° delay circuit provided between the third 90° hybrid coupler and the third antenna-side terminal; and
a second 180° delay circuit provided between the fourth 90° hybrid coupler and the fourth antenna-side terminal.
2. The Butler matrix circuit according to claim 1 , wherein the first to fourth 90° hybrid couplers and the first and second 90° delay circuits each include a transmission line provided on a substrate.
3. The Butler matrix circuit according to claim 2 , wherein the substrate includes a glass substrate or a silicon substrate.
4. A wireless communication terminal mounted with the Butler matrix circuit according to claim 1 .
5. A phased array antenna comprising:
four Butler matrix circuits; and
an array antenna including a plurality of antennas, wherein sixteen antennas of the plurality of antennas are coupled to respective first to fourth antenna-side terminals of the four Butler matrix circuits,
each of the four Butler matrix circuits including
four processing-circuit-side terminals,
four antenna-side terminals,
a first 90° hybrid coupler coupled to a first processing-circuit-side terminal and a second processing-circuit-side terminal,
a second 90° hybrid coupler coupled to a third processing-circuit-side terminal and a fourth processing-circuit-side terminal,
a third 90° hybrid coupler coupled to a first antenna-side terminal and a third antenna-side terminal,
a fourth 90° hybrid coupler coupled to a second antenna-side terminal and a fourth antenna-side terminal,
a first 90° delay circuit provided between the first 90° hybrid coupler and the third 90° hybrid coupler, and
a second 90° delay circuit provided between the first 90° hybrid coupler and the fourth 90° hybrid coupler,
the second 90° hybrid coupler being directly coupled to the third and fourth 90° hybrid couplers,
the first processing-circuit-side terminal of each of the Butler matrix circuits is coupled to a first terminal,
the second processing-circuit-side terminal of each of the Butler matrix circuits is coupled to a second terminal,
the third processing-circuit-side terminal of each of the Butler matrix circuits is coupled to a third terminal,
the fourth processing-circuit-side terminal of each of the Butler matrix circuits is coupled to a fourth terminal, and
the first to fourth terminals are coupled to a processing circuit including a switch circuit.
6. The phased array antenna according to claim 5 , wherein the sixteen antennas are arranged in four rows and four columns.
7. The phased array antenna according to claim 6 , wherein, in the array antenna,
the antennas arranged in even-numbered rows of each column have a positional relationship of 180° inversion of the antennas arranged in odd-numbered rows of an identical column, or
the antennas arranged in even-numbered columns of each row have a positional relationship of 180° inversion of the antennas arranged in odd-numbered columns of an identical row.
8. The phased array antenna according to claim 5 , wherein the first to fourth processing-circuit-side terminals are coupled, respectively, to the first to fourth terminals via dividers.
9. A front-end module comprising:
a Butler matrix circuit;
an array antenna including a plurality of antennas; and
a processing circuit including a switch circuit, which are stacked on each other,
the Butler matrix circuit including
four processing-circuit-side terminals,
four antenna-side terminals,
a first 90° hybrid coupler coupled to a first processing-circuit-side terminal and a second processing-circuit-side terminal,
a second 90° hybrid coupler coupled to a third processing-circuit-side terminal and a fourth processing-circuit-side terminal,
a third 90° hybrid coupler coupled to a first antenna-side terminal and a third antenna-side terminal,
a fourth 90° hybrid coupler coupled to a second antenna-side terminal and a fourth antenna-side terminal,
a first 90° delay circuit provided between the first 90° hybrid coupler and the third 90° hybrid coupler, and
a second 90° delay circuit provided between the first 90° hybrid coupler and the fourth 90° hybrid coupler,
the second 90° hybrid coupler being directly coupled to the third and fourth 90° hybrid couplers.
10. The front-end module according to claim 9 , comprising:
a first substrate; and
a second substrate, which are stacked on each other, wherein
the Butler matrix circuit is provided on a first surface of the first substrate,
the array antenna is provided on a second surface of the first substrate, and
the processing circuit is provided on the second substrate.
11. The front-end module according to claim 10 , wherein the Butler matrix circuit and each of the antennas are electrically coupled by a via provided in the first substrate.
12. The front-end module according to claim 10 , wherein the Butler matrix circuit and each of the antennas are electromagnetically coupled by a slot provided in the first substrate.