Abstract: Described herein are systems for radio-frequency (RF) localization. The systems developed by the inventors are designed to improve the accuracy of RF localization to millimeter and sub-millimeter ranges, and additionally, are designed to do so while also limiting manufacturing costs. The RF localization systems developed by the inventors leverage the relatively low costs associated with the manufacturing of printed circuit board assemblies (PCBAs). Manufacturing RF localization devices using PCBAs poses a number of challenges, including large minimum feature size and the presence of surface waves. Described herein are techniques for addressing challenges arising in connection with RF localization devices fabricated using PCBAs. One technique involves the use of slot-fed antennas, which makes the device efficient notwithstanding the large minimum feature size. Another technique involves the use of frequency selective surfaces for suppressing surface waves.

Abstract: A device comprising: a radio frequency (RF) coupler comprising input, output, and coupled ports; an antenna capable of receiving RF signals having a first characteristic and transmitting RF signals having a second characteristic, the antenna connected to the RF coupler to provide received RF signals to the input port of the RF coupler and transmit RF signals received at the input port via coupling to signals received at the coupled port; and signal transformation circuitry having an input connected to the output port of the RF coupler to receive RF signals provided by the antenna to the input port and an output connected to the coupled port, the signal transformation circuitry configured to transform first RF signals having the first characteristic received from the output port to second RF signals having the second characteristic and to provide them to the coupled port.

Abstract: A device comprising: a radio frequency (RF) coupler comprising input, output, and coupled ports; an antenna capable of receiving RF signals having a first characteristic and transmitting RF signals having a second characteristic, the antenna connected to the RF coupler to provide received RF signals to the input port of the RF coupler and transmit RF signals received at the input port via coupling to signals received at the coupled port; and signal transformation circuitry having an input connected to the output port of the RF coupler to receive RF signals provided by the antenna to the input port and an output connected to the coupled port, the signal transformation circuitry configured to transform first RF signals having the first characteristic received from the output port to second RF signals having the second characteristic and to provide them to the coupled port.

Abstract: A device comprising: a radio frequency (RF) coupler comprising input, output, and coupled ports; an antenna capable of receiving RF signals having a first characteristic and transmitting RF signals having a second characteristic, the antenna connected to the RF coupler to provide received RF signals to the input port of the RF coupler and transmit RF signals received at the input port via coupling to signals received at the coupled port; and signal transformation circuitry having an input connected to the output port of the RF coupler to receive RF signals provided by the antenna to the input port and an output connected to the coupled port, the signal transformation circuitry configured to transform first RF signals having the first characteristic received from the output port to second RF signals having the second characteristic and to provide them to the coupled port.

Abstract: Radio-frequencies (RF) antennas for use in micro-localization systems are described. The RF antennas described herein may enable localization of objects with high resolutions, such as in the order of one centimeter or less. The RF antennas may be further configured to reduce range error variability across different directions, so that the accuracy of a micro-localization system is substantially the same regardless of the position of the object. An illustrative RF antenna includes an emitting element having first and second conductive traces patterned to reduce the angular impulse delay variability of the RF antenna. The first conductive trace may form a first arm of a spiral and the second conductive trace may form a second arm of the spiral. At least one parameter of the spiral may be selected to reduce the angular impulse delay variability of the RF antenna.

Abstract: Radio-frequencies (RF) antennas for use in micro-localization systems are described. The RF antennas described herein may enable localization of objects with high resolutions, such as in the order of one centimeter or less. The RF antennas may be further configured to reduce range error variability across different directions, so that the accuracy of a micro-localization system is substantially the same regardless of the position of the object. An illustrative RF antenna includes an emitting element having first and second conductive traces patterned to reduce the angular impulse delay variability of the RF antenna. The first conductive trace may form a first arm of a spiral and the second conductive trace may form a second arm of the spiral. At least one parameter of the spiral may be selected to reduce the angular impulse delay variability of the RF antenna.

Abstract: Techniques for designing radio-frequency (RF) antennas for use in micro-localization systems are described. The techniques described herein allow RF designers to estimate how accurate a micro-localization system using the designed antenna will be once manufactured. As such, the techniques described herein enable RF designers to iterate the design of an RF antenna, for example by adjusting certain antenna design parameters in an iterative fashion, until a satisfactory degree of accuracy is achieved. In particular, described herein is angular impulse delay (AID), a metric that quantifies the time delay existing between the emission of an electromagnetic wave at a certain point in space and the reception of this electromagnetic wave at the assumed phase center of the antenna. The benefit of AID is that it allows RF designers to quantify the difference in the delays between different points in space and the phase center of an antenna.

Abstract: A device comprising: a radio frequency (RF) coupler comprising input, output, and coupled ports; an antenna capable of receiving RF signals having a first characteristic and transmitting RF signals having a second characteristic, the antenna connected to the RF coupler to provide received RF signals to the input port of the RF coupler and transmit RF signals received at the input port via coupling to signals received at the coupled port; and signal transformation circuitry having an input connected to the output port of the RF coupler to receive RF signals provided by the antenna to the input port and an output connected to the coupled port, the signal transformation circuitry configured to transform first RF signals having the first characteristic received from the output port to second RF signals having the second characteristic and to provide them to the coupled port.

Abstract: Radio-frequencies (RF) antennas for use in micro-localization systems are described. The RF antennas described herein may enable localization of objects with high resolutions, such as in the order of one centimeter or less. The RF antennas may be further configured to reduce range error variability across different directions, so that the accuracy of a micro-localization system is substantially the same regardless of the position of the object. An illustrative RF antenna includes a conductive housing forming a first cavity separated from a second cavity by a conductive wall. The RF antenna may further include an emitting element coupled to the conductive housing, a port coupled to the conductive housing, and an antenna feed electrically coupling the emitting element to the port. The antenna feed may pass through the cavities and the conductive wall. The antenna feed may comprise a symmetric and an asymmetric portion, disposed in the different cavities.

Abstract: A device comprising: a radio frequency (RF) coupler comprising input, output, and coupled ports; an antenna capable of receiving RF signals having a first characteristic and transmitting RF signals having a second characteristic, the antenna connected to the RF coupler to provide received RF signals to the input port of the RF coupler and transmit RF signals received at the input port via coupling to signals received at the coupled port; and signal transformation circuitry having an input connected to the output port of the RF coupler to receive RF signals provided by the antenna to the input port and an output connected to the coupled port, the signal transformation circuitry configured to transform first RF signals having the first characteristic received from the output port to second RF signals having the second characteristic and to provide them to the coupled port.

Abstract: A device comprising: a radio frequency (RF) coupler comprising input, output, and coupled ports; an antenna capable of receiving RF signals having a first characteristic and transmitting RF signals having a second characteristic, the antenna connected to the RF coupler to provide received RF signals to the input port of the RF coupler and transmit RF signals received at the input port via coupling to signals received at the coupled port; and signal transformation circuitry having an input connected to the output port of the RF coupler to receive RF signals provided by the antenna to the input port and an output connected to the coupled port, the signal transformation circuitry configured to transform first RF signals having the first characteristic received from the output port to second RF signals having the second characteristic and to provide them to the coupled port.

Abstract: A device comprising: a radio frequency (RF) coupler comprising input, output, and coupled ports; an antenna capable of receiving RF signals having a first center frequency and transmitting RF signals having a second center frequency, the antenna connected to the RF coupler to provide received RF signals to the input port of the RF coupler and transmit RF signals received at the input port via coupling to signals received at the coupled port; and signal transformation circuitry having an input connected to the output port of the RF coupler to receive RF signals provided by the antenna to the input port and an output connected to the coupled port, the signal transformation circuitry configured to transform first RF signals having the first center frequency received from the output port to second RF signals having the second center frequency and to provide them to the coupled port.