Device for positioning a first object relative to a second object

A device for positioning a first object relative to a second object which includes a metal surface, where the first object has a robotic head and the second object is located by a position sensing system comprising:

• a sensor and a transponder;
• said sensor comprising a transmitter and receiver unit in the robotic head and said transponder (50) is located on the metal surface of said second object;
• said transponder operates at a frequency in the microwave range and is enabled to reradiate a signal received from said sensor, said transponder thereby operating to enable positioning of said robotic head relative to said second object, said transponder comprising a microstrip antenna element (20), (60), (70), a dielectric material plate (28) and a ground plane (21), said dielectric material plate having two sides;
• said ground plane (21) being of similar size as the microstrip antenna element and wherein the transponder is arranged to cooperate with said metal surface of said second object which thereby provides a reflector plane (22), located behind the transponder, to obtain an antenna radiating diagram that is directed perpendicular out from the transponder on the opposite side from said reflection plane;
• said transponder having a power source (40) and associated electronic elements, placed inside the perimeter of said microstrip antenna element (20), (60), (70) and on one side of the dielectric plate;
• said microstrip antenna element being a patch antenna element, and the size of said ground plane (21) provides a diametric extension of less than 1.7 times, and more than 0.6 times that of the size of the antenna element, whereby the reflection of the back lobe thereby created is reflected by said metal surface of the second object located behind the transponder and is added to the direct signal from the microstrip antenna to form a radiating diagram directed perpendicular to the dielectric material plate and the microstrip antenna element.

A device for positioning a first object relative to a second object which includes a metal surface, where the first object has a robotic head and the second object is located by a position sensing system comprising:

• a sensor and a transponder;
• said sensor comprising a transmitter and receiver unit in the robotic head and said transponder (50) is located on the metal surface of said second object;
• said transponder operates at a frequency in the microwave range and is enabled to reradiate a signal received from said sensor, said transponder thereby operating to enable positioning of said robotic head relative to said second object, said transponder comprising a microstrip antenna element (20), (60), (70), a dielectric material plate (28) and a ground plane (21), said dielectric material plate having two sides;
• said ground plane (21) being of similar size as the microstrip antenna element and wherein the transponder is arranged to cooperate with said metal surface of said second object which thereby provides a reflector plane (22), located behind the transponder, to obtain an antenna radiating diagram that is directed perpendicular out from the transponder on the opposite side from said reflection plane;
• said transponder having a power source (40) and associated electronic elements, placed inside the perimeter of said microstrip antenna element (20), (60), (70) and on one side of the dielectric plate;
• said microstrip antenna element comprising at least one dipole antenna element of a folded type being arranged with a said ground plane that has a size providing a diametric extension of less than 1.7 times, and more than 0.6 times that of the effective size of the microstrip antenna element, whereby the reflection of the back lobe thereby created is reflected by said metal surface of the second object behind the transponder, said reflection of the back lobe from the metal surface being added to the direct signal from the microstrip antenna element to form a radiating diagram directed perpendicular to the dielectric material plate and the microstrip antenna element.