Phase shifter comprising selectable first and second all-pass filters, where the all-pass filters include capacitors and inductors of determined values to achieve impedance matching

A phase shifter comprising:

• a first all-pass filter including a plurality of elements;
• a second all-pass filter including a plurality of elements;
• a first switch to provide a signal to either the first all-pass filter or the second all-pass filter;
• and
• a second switch to select the signal having passed through the first all-pass filter or the signal having passed through the second all-pass filter, wherein
• the first all-pass filter includes a first inductor, a second inductor, a first capacitor, a second capacitor, and a third capacitor as the plurality of elements,
• the second all-pass filter includes a third inductor, a fourth inductor, a fourth capacitor, a fifth capacitor, and a sixth capacitor as the plurality of elements,
• the first inductor is inserted in a first path that connects the first switch to the second switch,
• a first end of the first capacitor is connected to a first end of the first inductor,
• a first end of the second capacitor is connected to a second end of the first inductor,
• a first end of the second inductor is connected to a second end of each of the first capacitor and the second capacitor,
• a first end of the third capacitor is connected to a second end of the second inductor, and a second end of the third capacitor is grounded,
• the third inductor is inserted in a second path that connects the first switch to the second switch,
• a first end of the fourth capacitor is connected to a first end of the third inductor,
• a first end of the fifth capacitor is connected to a second end of the third inductor,
• a first end of the fourth inductor is connected to a second end of each of the fourth capacitor and the fifth capacitor,
• a first end of the sixth capacitor is connected to a second end of the fourth inductor, and a second end of the sixth capacitor is grounded, and
• values of the plurality of capacitors and inductors included in the first and second all-pass filters are determined such that impedance matching is achieved in a desired frequency band.