Digital phase shift circuit and digital phase shifter
A digital phase shift circuit includes: a signal line extending in a predetermined direction; two inner lines disposed on both one side and another side of the signal line and separated a predetermined distance from the signal line; two outer lines provided at positions which are farther from the signal line than the inner lines on both the one side and the other side; a first grounding conductor electrically connected to one end of each of the inner lines and the outer lines; and a second grounding conductor electrically connected to other ends of the outer lines, and the predetermined distance is set to be less than 10 μm.
1. A digital phase shift circuit comprising:
a signal line extending in a predetermined direction;
two inner lines disposed on both one side and the other side of the signal line and separated a predetermined distance from the signal line;
two outer lines provided at positions which are farther from the signal line than the inner lines on both the one side and the other side;
a first grounding conductor electrically connected to one end of each of the inner lines and the outer lines;
a second grounding conductor electrically connected to other ends of the outer lines;
a first electronic switch connected between another end of an inner line of the inner lines on the one side and the second grounding conductor;
a second electronic switch connected between another end of an inner line of the inner lines on the other side and the second grounding conductor,
a capacitor connected between the signal line and the second grounding conductor; and
a fourth electronic switch connected in series to the capacitor,
wherein the predetermined distance is set to be less than 10 μm, and
a size of an upper electrode of the capacitor is equal to or less than a width of the signal line.
2. The digital phase shift circuit according to claim 1 , wherein the predetermined distance is set to be equal to or less than 2 μm.
3. The digital phase shift circuit according to claim 1 , comprising a third electronic switch connected between the signal line and the first grounding conductor or the second grounding conductor.
4. The digital phase shift circuit according to claim 1 , wherein parts of both or one of the first grounding conductor and the second grounding conductor, which correspond to areas between the outer lines and the inner lines, are formed in a multi-layered structure.
5. The digital phase shift circuit according to claim 1 , wherein the signal line is formed in a first conductive layer, and
wherein the inner lines are formed in a second conductive layer facing the first conductive layer with an insulating layer interposed therebetween.
6. A digital phase shifter comprising:
a plurality of the digital phase shift circuits according to claim 1 connected in a cascade manner,
wherein a signal in a frequency band from a first frequency to a second frequency higher than the first frequency is shifted in phase by the plurality of digital phase shift circuits connected in a cascade manner,
wherein each of the plurality of digital phase shift circuits operates in either one operation mode of a low-delay mode in which the first electronic switch and the second electronic switch are set to a closed state and a high-delay mode in which the first electronic switch and the second electronic switch are set to an open state, and
wherein a magnitude relationship of the signal varying according to a control state of operation modes of the plurality of digital phase shift circuits differs between when a frequency of the signal is the first frequency and when the frequency of the signal is the second frequency.
7. A digital phase shifter comprising:
a plurality of the digital phase shift circuits according to claim 1 connected in a cascade manner,
wherein a signal in a frequency band from a first frequency to a second frequency higher than the first frequency is shifted in phase by the plurality of digital phase shift circuits connected in a cascade manner,
wherein each of the plurality of digital phase shift circuits operates in either one operation mode of a low-delay mode in which the first electronic switch and the second electronic switch are set to a closed state and a high-delay mode in which the first electronic switch and the second electronic switch are set to an open state, and
wherein a magnitude relationship between an amplitude of the signal when all the plurality of digital phase shift circuits are in the low-delay mode and an amplitude of the signal when all the plurality of digital phase shift circuits are in the high-delay mode differs between when a frequency of the signal is the first frequency and when the frequency of the signal is the second frequency.
8. A digital phase shift circuit comprising:
a signal line extending in a predetermined direction;
two inner lines disposed on both one side and the other side of the signal line and separated a predetermined distance from the signal line;
two outer lines provided at positions which are farther from the signal line than the inner lines on both the one side and the other side;
a first grounding conductor electrically connected to one end of each of the inner lines and the outer lines a second grounding conductor electrically connected to other ends of the outer lines;
a first electronic switch connected between another end of an inner line of the inner lines on the one side and the second grounding conductor; and
a second electronic switch connected between another end of an inner line of the inner lines on the other side of the second grounding conductor,
wherein the predetermined distance is set to be less than 10 μm,
wherein the first electronic switch and the second electronic switch are field-effect transistors, and
wherein a size of each of the field-effect transistors is equal to or greater than a length obtained by summing a width of the first grounding conductor and a width of the second grounding conductor.