Antennas for radio-frequency localization
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.
1. A radio-frequency (RF) device comprising:
one or more substrates collectively comprising:
a first RF antenna configured for wireless communication in a first RF band;
a second RF antenna configured for wireless communication in a second RF band different from the first RF band;
a first slot and a second slot, wherein the first and second slots have different shapes relative to each other;
a first antenna feed coupled to the first slot, wherein the first antenna feed is configured to communicate with the first RF antenna through the first slot; and
a second antenna feed coupled to the second slot, wherein the second antenna feed is configured to communicate with the second RF antenna through the second slot.
2. The RF device of claim 1 , wherein the one or more substrates comprises a first substrate and a second substrate, wherein the first substrate comprises the first RF antenna, the first slot and the first antenna feed, and wherein the second substrate comprises the second RF antenna, the second slot and the second antenna feed.
3. The RF device of claim 1 , wherein the one or more substrates comprises a single substrate comprising the first and second RF antennas, the first and second slots and the first and second antenna feeds.
4. The RF device of claim 1 , wherein the first slot is L-shaped and the second slot is not L-shaped.
5. The RF device of claim 1 , wherein the second slot is ring-shaped and the first slot is not ring-shaped.
6. The RF device of claim 1 , wherein the first slot has a segmented contour and the second slot has a continuous contour.
7. The RF device of claim 1 , wherein the first slot is L-shaped and the second slot is ring-shaped.
8. The RF device of claim 1 , wherein:
the first RF antenna is patterned on a first conductive layer of the one or more substrates;
the first RF antenna feed is patterned on a second conductive layer of the one or more substrates; and
the first slot is formed through a third conductive layer of the one or more substrates, the third conductive layer being positioned between the first and second conductive layers.
9. The RF device of claim 1 , wherein:
the first RF antenna is configured to receive a first RF signal having a first center frequency from an interrogator device different from the RF device,
the second RF antenna is configured to transmit, to the interrogator device, a second RF signal having a second center frequency different from the first center frequency, and
the RF device further comprises circuitry configured to:
receive the first RF signal from the first RF antenna,
generate the second RF signal in response to receiving the first RF signal, and
provide to the second RF antenna the second RF signal to be transmitted by the second RF antenna.
10. A radio-frequency (RF) device comprising:
one or more substrates collectively comprising:
a first RF antenna configured for wireless communication in a first RF band;
a second RF antenna configured for wireless communication in a second RF band different from the first RF band;
a first slot and a second slot, wherein:
the first slot is L-shaped and the second slot is not L-shaped, or
the second slot is ring-shaped and the first slot is not ring-shaped, or
the first slot has a segmented contour and the second slot has a continuous contour, or
the first slot is L-shaped and the second slot is ring-shaped,
a first antenna feed coupled to the first slot, wherein the first antenna feed is configured to communicate with the first RF antenna through the first slot; and
a second antenna feed coupled to the second slot, wherein the second antenna feed is configured to communicate with the second RF antenna through the second slot.
11. The RF device of claim 10 , wherein the one or more substrates comprises a first substrate and a second substrate, wherein the first substrate comprises the first RF antenna, the first slot and the first antenna feed, and wherein the second substrate comprises the second RF antenna, the second slot and the second antenna feed.
12. The RF device of claim 10 , wherein the one or more substrates comprises a single substrate comprising the first and second RF antennas, the first and second slots and the first and second antenna feeds.
13. The RF device of claim 10 , wherein:
the first RF antenna is patterned on a first conductive layer of the one or more substrates;
the first RF antenna feed is patterned on a second conductive layer of the one or more substrates; and
the first slot is formed through a third conductive layer of the one or more substrates, the third conductive layer being positioned between the first and second conductive layers.
14. The RF device of claim 10 , wherein:
the first RF antenna is configured to receive a first RF signal having a first center frequency from an interrogator device different from the RF device,
the second RF antenna is configured to transmit, to the interrogator device, a second RF signal having a second center frequency different from the first center frequency, and
the RF device further comprises circuitry configured to:
receive the first RF signal from the first RF antenna,
generate the second RF signal in response to receiving the first RF signal, and
provide to the second RF antenna the second RF signal to be transmitted by the second RF antenna.