Digital phase shifter
A digital phase shifter includes a plurality of digital phase shift circuits connected in cascade and one or more bend-type connection units each configured to make a connection between two digital phase shift circuits of the plurality of digital phase shift circuits. Each of the digital phase shift circuits includes at least a signal line, a pair of inner lines provided at both sides of the signal line, a pair of outer lines provided outside of the inner lines, a first ground conductor connected to one ends of the inner lines and the outer lines, a second ground conductor connected to the other ends of the outer lines, and a pair of electronic switches provided between the other ends of the inner lines and the second ground conductor. Each of the digital phase shift circuits is a circuit set in a low-delay mode in which a return current flows through the inner line or a high-delay mode in which a return current flows through the outer line. The plurality of digital phase shift circuits connected in cascade are arranged in a spiral shape via the connection units.
1. A digital phase shifter comprising:
a plurality of digital phase shift circuits connected in cascade; and
one or more bend-type connection units each configured to make a connection between two digital phase shift circuits of the plurality of digital phase shift circuits,
wherein each of the digital phase shift circuits includes at least a signal line, a pair of inner lines having a respective inner line of the pair at each side of the signal line, a pair of outer lines provided outside of the inner lines, a first ground conductor connected to one ends of the inner lines and the outer lines, a second ground conductor connected to the other ends of the outer lines, and a pair of electronic switches provided between the other ends of the inner lines and the second ground conductor,
wherein each of the digital phase shift circuits is a circuit set in a low-delay mode in which a return current flows through the pair of inner lines or a high-delay mode in which a return current flows through the pair of outer lines, and
wherein the plurality of digital phase shift circuits connected in cascade are arranged in a spiral shape via the connection units.
2. The digital phase shifter according to claim 1 , further comprising a transmission line connected to the signal line of a terminal digital phase shift circuit that is the digital phase shift circuit located at an innermost circumference among the plurality of digital phase shift circuits arranged in the spiral shape and through which a high-frequency signal flowing through the signal line is transmitted,
wherein the transmission line is formed above or below the connection unit.
3. The digital phase shifter according to claim 1 , wherein each of the connection units has a structure that is bent at 90 degrees.
4. The digital phase shifter according to claim 1 , further comprising a transmission line connected to the signal line of a terminal digital phase shift circuit that is the digital phase shift circuit located at an innermost circumference among the plurality of digital phase shift circuits arranged in the spiral shape and through which a high-frequency signal flowing through the signal line is transmitted,
wherein the transmission line is formed on a layer different from a layer where the signal line is formed.
5. The digital phase shifter according to claim 4 , further comprising a transmission-unit ground layer arranged at least one of above and below the transmission line,
wherein the transmission-unit ground layer is connected to at least one of the pair of inner lines or the pair of outer lines via a transmission-unit via-hole.
6. The digital phase shifter according to claim 5 , comprising a ground line connected to the pair of inner lines of the terminal digital phase shift circuit and extending along the transmission line.
7. The digital phase shifter according to claim 6 , wherein the transmission-unit ground layer is connected to at least the ground line via the transmission-unit via-hole or a via-hole different from the transmission-unit via-hole.
8. The digital phase shifter according to claim 1 , wherein the connection unit includes:
a first connection line configured to connect the signal line of one digital phase shift circuit of the two digital phase shift circuits and the signal line of the other digital phase shift circuit of the two digital phase shift circuits;
a pair of second connection lines respectively configured to connect one inner line of the pair of inner lines of the one digital phase shift circuit and one inner line of the pair of inner lines of the other digital phase shift circuit, and connect the other inner line of the pair of inner lines of the one digital phase shift circuit and the other inner line of the pair of inner lines of the other digital phase shift circuit; and
a connection-unit ground layer arranged at least one of above and below the first connection line.
9. The digital phase shifter according to claim 8 , further comprising a pair of third connection lines respectively configured to connect one outer line of the pair of outer lines of the one digital phase shift circuit and one outer line of the pair of outer lines of the other digital phase shift circuit, and connect the other outer line of the pair of outer lines of the one digital phase shift circuit and the other outer line of the pair of outer lines of the other digital phase shift circuit.
10. The digital phase shifter according to claim 8 , wherein the second connection line and the connection-unit ground layer are connected by a connection-unit via-hole.