Compact phase shifter circuit using coupled lines

A switched-line phase shifter for producing a differential phase shift over a frequency bandwidth of operation, said switched-line phase shifter comprising:

• an input port;
• an output port;
• a first transmission path comprising a first Schiffman section having a first electrical length;
• a second transmission path comprising said first Schiffman section and a second Schiffman section having a second electrical length;
• and
• at least one switch for alternately connecting said first Schiffman section and a combination of said first Schiffman section and said second Schiffman section between said input port and said output port.

A switched-line phase shifter for producing a differential phase shift over a frequency bandwidth of operation, said switched-line phase shifter comprising:

• an input port;
• an output port;
• a first transmission path comprising a first Schiffman section having a first electrical length that is a first non-integer multiple of a desired operating frequency quarter-wavelength;
• a second transmission path comprising said first Schiffman section and a second Schiffman section having a second electrical length;
• and
• at least one switch for alternately connecting said first Schiffman section and a combination of said first Schiffman section and said second Schiffman section between said input port and said output port.

A switched-line phase shifter for producing a differential phase shin over a frequency bandwidth of operation, said switched-line phase shifter comprising:

• an input port;
• an output port;
• a first transmission path comprising a first Schiffman section having a first electrical length;
• a second transmission path comprising said first Schiffman section and a second Schiffman section having a second electrical length, wherein the difference between the first electrical length of the first Schiffman section and the second electrical length of the second Schiffman section is substantially different than the differential phase shift at a desired operating frequency;
• and
• at least one switch for alternately connecting said first Schiffman section and a combination of said first Schiffman section and said second Schiffman section between said input port and said output port.