Spiral balun

A spiral balun, comprising:

• a substrate having a first surface;
• a first transmission line formed on said first surface and having a first end coupled to receive an input signal and having a second end, said first transmission line having a first section proximate said first end forming a first spiral in a first direction and a second section proximate said second end forming a second spiral in a second direction;
• a second transmission line formed on said first surface and having a first end for providing a first output and a second end for coupling to a first potential, said second transmission line interleaving said first section forming a third spiral that winds in said second direction from its first end to its second end;
• and
• a third transmission line formed on said first surface having a first end for providing a second output and a second end for coupling to a second potential, said third transmission line interleaving said second section and forming a fourth spiral which winds in said first direction from its first end to its second end.

A balanced-mixer having a first terminal, a second terminal, and having an input terminal for receiving a reference signal, comprising:

• a substrate;
• at least one anti-parallel diode pair formed on said substrate;
• a first spiral balun, comprising:
• a first transmission line formed on said substrate having a first end coupled to receive said reference signal and having a second end, said first transmission line having a first section proximate said first end forming a first spiral in a first direction and a section proximate said second end forming a second spiral in a second direction;
• a second transmission line formed on said substrate and having a first end coupled to said at least one anti-parallel diode pair and having a second end for coupling to a first potential, said second transmission line forming a third spiral that interleaves said first section and winds in said second direction;
• and
• a third transmission line formed on said substrate having first end coupled to said at least one anti-parallel diode pair and a second end for coupling to a second potential, said third transmission line forming a fourth spiral that interleaves said second section and winds in said first direction;
• and
• a second spiral balun comprising:
• a fourth transmission line formed on said substrate and having a first end coupled to said first terminal and having a second end, said first transmission line having a third section proximate said first end forming a fifth spiral in said first direction and a fourth section proximate said second end forming a sixth spiral in said second direction;
• a fifth transmission line formed on said substrate and having a fist end coupled to said at least one anti-parallel diode pair and having a second end coupled to said second terminal, said fifth transmission line forming a seventh spiral that interleaves said third section and winds in said second direction;
• and
• a sixth transmission line formed on said substrate having a first end coupled to said at least one anti-parallel diode pair and a second end coupled to said second terminal, said third transmission line forming an eighth spiral that interleaves said fourth section and winds in said first direction.