Hybrid antenna with dynamic signal routing for free-space and near-metal environments
Hybrid antenna structures for seamless integration of free space and surface electromagnetic wave (SEW) radiation are described. In some examples, the hybrid antenna may comprise a helical antenna free space radiator coupled to an SEW antenna feed point. The system may include a radio frequency switch and reflectometers configured to sense impedance at the helical antenna and SEW feed point, dynamically routing signals based on the sensed impedance. A free space radiation feed line and an SEW radiation feed line may be connected to the radio frequency switch and reflectometers, enabling efficient operation in varying environments. This configuration may allow the antenna to function as a conventional free space radiator or a plasmonic surface wave antenna, optimizing performance without user intervention.
1 . A hybrid antenna structure, comprising:
a helical antenna free space radiator;
a surface electromagnetic wave (SEW) antenna feed point coupled to the helical antenna free space radiator;
an RF switch and reflectometers configured to sense impedance at the helical antenna free space radiator and the SEW antenna feed point; and
a free space radiation feed line and an SEW radiation feed line connected to the RF switch and the reflectometers, the RF switch dynamically routing signals to the helical antenna free space radiator or the SEW antenna feed point in response to the impedance.
2 . The hybrid antenna structure of claim 1 , further comprising an antenna ground positioned between the helical antenna free space radiator, the RF switch, and the reflectometers to provide a reference impedance for the free space radiation feed line and the SEW radiation feed line.
3 . The hybrid antenna structure of claim 1 , wherein the RF switch and the reflectometers are configured to measure an S 11 return loss at the helical antenna free space radiator and the SEW antenna feed point to dynamically determine the routing of the signals.
4 . The hybrid antenna structure of claim 1 , further comprising an SMA connector coupled to the free space radiation feed line and the SEW radiation feed line to facilitate external connection to an RF feed line from a transmitter.
5 . The hybrid antenna structure of claim 1 , wherein the SEW radiation feed line is configured to transmit the signals to the SEW antenna feed point in response to the impedance sensed by the RF switch and the reflectometers indicating a low reflection coefficient at the SEW antenna feed point.
6 . The hybrid antenna structure of claim 1 , wherein the helical antenna free space radiator is configured to operate in response to the impedance sensed by the RF switch and the reflectometers indicating a low reflection coefficient at the helical antenna free space radiator.
7 . The hybrid antenna structure of claim 1 , wherein the RF switch and the reflectometers are configured to dynamically alternate signal routing between the free space radiation feed line and the SEW radiation feed line based on the impedance sensed at the helical antenna free space radiator and the SEW antenna feed point.
8 . The hybrid antenna structure of claim 1 , wherein the SEW radiation feed line is configured to transmit the signals to the SEW antenna feed point in response to the RF switch and the reflectometers detecting a high reflection coefficient at the helical antenna free space radiator.
9 . The hybrid antenna structure of claim 1 , wherein the RF switch is configured to isolate the free space radiation feed line from the SEW radiation feed line during signal transmission to prevent interference between the helical antenna free space radiator and the SEW antenna feed point.
10 . The hybrid antenna structure of claim 1 , wherein the RF switch and the reflectometers are configured to sense the impedance variations caused by proximity to metallic surfaces and dynamically adjust the routing of the signals to the helical antenna free space radiator or the SEW antenna feed point.
11 . The hybrid antenna structure of claim 4 , wherein the SMA connector is configured to provide a detachable interface for connecting the free space radiation feed line and the SEW radiation feed line to an external RF feed line from the transmitter.
12 . The hybrid antenna structure of claim 1 , wherein the helical antenna free space radiator is configured to radiate the signals in response to the RF switch and the reflectometers detecting a low reflection coefficient at the free space radiation feed line.
13 . The hybrid antenna structure of claim 1 , wherein the RF switch and the reflectometers are configured to dynamically sense and route the signals to the SEW antenna feed point in response to environmental conditions affecting the impedance at the helical antenna free space radiator.
14 . A method of manufacturing a hybrid antenna structure, comprising:
providing a helical antenna free space radiator;
coupling a surface electromagnetic wave (SEW) antenna feed point to the helical antenna free space radiator;
configuring an RF switch and reflectometers to sense impedance at the helical antenna free space radiator and the SEW antenna feed point; and
connecting a free space radiation feed line and an SEW radiation feed line to the RF switch and the reflectometers, wherein the RF switch dynamically routes signals to the helical antenna free space radiator or the SEW antenna feed point in response to the impedance.
15 . The method of manufacturing a hybrid antenna structure of claim 14 , further comprising positioning an antenna ground between the helical antenna free space radiator, the RF switch, and the reflectometers to provide a reference impedance for the free space radiation feed line and the SEW radiation feed line.
16 . The method of manufacturing a hybrid antenna structure of claim 14 , wherein the RF switch and the reflectometers are configured to measure an S 11 return loss at the helical antenna free space radiator and the SEW antenna feed point to dynamically determine the routing of the signals.
17 . The method of manufacturing a hybrid antenna structure of claim 14 , further comprising coupling an SMA connector to the free space radiation feed line and the SEW radiation feed line to facilitate external connection to an RF feed line from a transmitter.
18 . The method of manufacturing a hybrid antenna structure of claim 14 , wherein the SEW radiation feed line is configured to transmit the signals to the SEW antenna feed point in response to the impedance sensed by the RF switch and the reflectometers indicating a low reflection coefficient at the SEW antenna feed point.
19 . The method of manufacturing a hybrid antenna structure of claim 14 , wherein the helical antenna free space radiator is configured to operate in response to the impedance sensed by the RF switch and the reflectometers indicating a low reflection coefficient at the helical antenna free space radiator.
20 . A kit, comprising:
a helical antenna free space radiator;
a surface electromagnetic wave (SEW) antenna feed point coupled to the helical antenna free space radiator;
an RF switch and reflectometers configured to sense impedance at the helical antenna free space radiator and the SEW antenna feed point; and
a free space radiation feed line and an SEW radiation feed line connected to the RF switch and the reflectometers, the RF switch dynamically routing signals to the helical antenna free space radiator or the SEW antenna feed point in response to the impedance.