Active metasurface architectures
Antennas and methods for using the same are disclosed. In some embodiments, an antenna includes a metasurface having radiating antenna elements and amplifiers configured to amplify signals for the radiating antenna elements, wherein, for each of the radiating antenna elements, the metasurface includes one or both of: a receive path having a low noise amplifier (LNA) configured to amplify a first set of received signals, at least one radiating antenna element configured to receive the first set of received signals, and a transmit path having a power amplifier (PA) configured to amplify a second set of transmit signals, the second set of transmit signals to be transmitted from the one radiating antenna element.
1 . An antenna comprising:
a metasurface having radiating antenna elements and amplifiers configured to amplify signals for the radiating antenna elements, wherein, for each of the radiating antenna elements, the metasurface includes one or both of:
a receive path having a low noise amplifier (LNA) between a first coupling element and said each radiating antenna element, the LNA configured to amplify a first set of received signals, said each radiating antenna element configured to receive the first set of received signals, and
a transmit path having a power amplifier (PA) between a second coupling element and said each radiating antenna element, the PA configured to amplify a second set of transmit signals, the second set of transmit signals to be transmitted from said each radiating antenna element; and
a waveguide coupled to the metasurface.
2 . The antenna of claim 1 wherein the receive path is configured to amplify the first set of received signals with the LNA after the metasurface is modulated to form a beam and the transmit path is configured to amplify the second set of signals with the PA before modulation.
3 . The antenna of claim 2 wherein at least one of the radiating antenna elements comprises:
a substrate having a top and a bottom;
a frequency tunable radiating element coupled to the substrate to receive and to transmit signals;
a first transmission line attached to the top of the substrate and electrically coupled to the tunable radiating element to transfer the signals to and from the tunable radiating element;
an LNA coupled to the first transmission line to amplify received signals received by the tunable radiating element;
a second transmission line coupled to the top of the substrate to receive the amplified received signals from the LNA; and
a coupling slot in a ground plane coupled to the bottom of the substrate to couple the amplified received signals from the second transmission line.
4 . The antenna of claim 3 further comprising:
a PA coupled to the first and second transmission lines to amplify transmit signals to be transmitted by the tunable radiating element, and
wherein the tunable radiating element is loaded with a tunable element to tune the radiating element.
5 . The antenna of claim 4 wherein the tunable element comprises a varactor or a tunable capacitor.
6 . The antenna of claim 3 wherein at least one of the first and second transmission lines is a microstrip line.
7 . The antenna of claim 2 wherein at least one of the radiating antenna elements comprises:
a multi-layer printed circuit board (PCB) in which the circuit layers are electrically coupled to transfer signals using one or more hot vias;
a tunable slot antenna coupled to a top of a top layer of the PCB to receive and to transmit signals;
a first transmission line attached to the top of the top layer of the PCB and electrically coupled to the tunable slot antenna to transfer the signals to and from the tunable radiating element;
an LNA coupled to the first transmission line to amplify received signals received by the tunable slot antenna;
a second transmission line attached to the top of the top layer of the PCB to receive the amplified received signals from the LNA; and
a coupling slot in coplanar waveguide transmission line coupled to a bottom layer of the PCB to couple the amplified received signals from the second transmission line.
8 . The antenna of claim 7 further comprising:
a PA coupled to the first and second transmission lines to amplify transmit signals to be transmitted by the tunable slot antenna, and
wherein the tunable slot antenna is loaded with a tunable element to tune the tunable slot antenna.
9 . The antenna of claim 8 wherein the tunable element comprises a varactor.
10 . The antenna of claim 7 wherein at least one of the first and second transmission lines is a coplanar waveguide transmission line.
11 . The antenna of claim 1 wherein the receive path is configured to amplify the first set of received signals with the LNA after hologram modulation and application of phase and amplitude adjustments for beamforming.
12 . The antenna of claim 1 wherein the transmit path is configured to amplify the second set of signals with the PA before hologram modulation and application of phase and amplitude adjustments for beamforming.
13 . The antenna of claim 1 wherein the receive path is configured to amplify the first set of received signals with the LNA before modulation and the transmit path is configured to amplify the second set of received signals with the PA after modulation.
14 . The antenna of claim 13 wherein at least one of the radiating antenna elements comprises:
a substrate having a top and a bottom;
a frequency tunable radiating element coupled to the substrate to receive or to transmit signals;
a first transmission line attached to the top of the substrate and electrically coupled to the tunable radiating element to transfer the signals to and from the tunable radiating element;
an LNA coupled to the first transmission line to amplify received signals received by the tunable radiating element;
a second transmission line coupled to the top of the substrate to receive the amplified received signals from the LNA; and
a tunable slot in a ground plane coupled to the bottom of the substrate for coupling the amplified received signals from the second transmission line.
15 . The antenna of claim 14 further comprising:
a PA coupled to the first and second transmission lines to amplify transmit signals to be transmitted by the tunable radiating element, and
wherein the tunable slot is loaded with a tunable element to tune the resonance frequency of the slot.
16 . The antenna of claim 15 wherein the tunable element comprises a varactor or a tunable capacitor.
17 . The antenna of claim 14 wherein at least one of the first and second transmission lines is a microstrip line.
18 . The antenna of claim 13 wherein at least one of the radiating antenna elements comprises:
a substrate having a top and a bottom;
a first radiating element coupled to the substrate to receive and to transmit signals;
a first transmission line attached to the top of the substrate and electrically coupled to the first radiating element to transfer the signals to and from the patch antenna;
an LNA coupled to the first transmission line to amplify received signals received by the first radiating element;
a second transmission line attached to the top of the substrate to receive the amplified received signals from the LNA; and
a tunable slot in a ground plane attached to the bottom of the substrate to couple the amplified received signals from the second transmission line to the waveguide, wherein the tunable slot is loaded with a tunable element coupled to the second transmission line to tune the tunable slot.
19 . The antenna of claim 18 further comprising:
a PA coupled to the first and second transmission lines to amplify transmit signals to be transmitted by the radiating element.
20 . The antenna of claim 18 wherein the tunable element comprises a varactor.
21 . The antenna of claim 18 wherein at least one of the first and second transmission lines is a microstrip line.
22 . The antenna of claim 1 wherein the receive path is configured to amplify the first set of received signals with the LNA before hologram modulation and application of phase and amplitude adjustments for beamforming and the transmit path is configured to amplify the second set of signals with the PA after hologram modulation and application of phase and amplitude adjustments for beamforming.