Radio frequency antenna with varying impedance for wearable

A device comprising:

• a first portion of an antenna on a substrate, wherein the first portion of the antenna comprises:
• a first end,
• a second end,
• a first point at a first distance from the first end,
• a second point at a second distance from the first end, and
• a third point at a third distance from the first end;
• a second portion of the antenna on the substrate, wherein the second portion of the antenna comprises:
• a third end,
• a fourth end,
• a fourth point at a fourth distance from the third end,
• a fifth point at a fifth distance from the third end, and
• a sixth point at a sixth distance from the third end;
• a transmitter having a transmitter output connected to the first portion of the antenna and to the second portion of the antenna;
• a receiver having a receiver input connected to the first portion of the antenna and to the second portion of the antenna;
• a first memory, storing computer-executable instructions;
• and
• a first hardware processor, wherein the first hardware processor executes the computer-executable instructions to:
• operate the transmitter to generate one or more signals;
• operate the receiver to receive the one or more signals;
• and
• determine one or more signal characteristic values of the one or more signals as received by the receiver.

A device comprising:

• a first portion of an antenna on a substrate, wherein the first portion of the antenna comprises:
• a first end,
• a second end,
• a first point at a first distance from the first end,
• a second point at a second distance from the first end, and
• a third point at a third distance from the first end;
• and
• a second portion of the antenna on the substrate, wherein the second portion of the antenna comprises:
• a third end,
• a fourth end,
• a fourth point at a fourth distance from the third end,
• a fifth point at a fifth distance from the third end, and
• a sixth point at a sixth distance from the third end,
• wherein:
• a first section of the first portion of the antenna that is adjacent to a second section of the second portion of the antenna is not parallel to the second section.