Abstract: A surface wave antenna system is presented. The surface wave antenna system is configured to be coupled to a surface and includes an antenna and a radiation modifier. The radiation modifier includes a material having a graded dielectric constant. A final portion of the radiation modifier includes material having a dielectric constant that produces a signal phase velocity in signals emitted from the radiation modifier that is substantially equal to a phase velocity of signals on the surface.

Abstract: An electronic system comprising: 1) an antenna; 2) a transmission line coupled to the antenna; 3) RF electronics circuitry coupled to the transmission line that is sensitive to a high frequency EMI/RF signal on the transmission line; and 4) a protection circuit comprising passive mode circuitry operational when the electronic system is powered off and active mode circuitry operational when the electronic system is powered on.

Abstract: A surface wave antenna system is presented. The surface wave antenna system is configured to be coupled to a surface and includes an antenna and a radiation modifier. The radiation modifier includes a material having a graded dielectric constant. A final portion of the radiation modifier includes material having a dielectric constant that produces a signal phase velocity in signals emitted from the radiation modifier that is substantially equal to a phase velocity of signals on the surface.

Abstract: An antenna assembly for use in a tile architecture antenna system. The antenna assembly comprises: i) a first substrate layer having a first surface; ii) a first antenna disposed in an X-Y plane on the first surface of the first substrate layer; iii) a second substrate layer having a first surface, the second substrate layer displaced in the Z-direction with respect to the X-Y plane on the first surface of the first substrate layer; and iv) a first tuning balun disposed on the first surface of the second substrate layer and coupled to the first antenna by means of a first feed via. The antenna assembly further comprises a first transmission line disposed on the first surface of the second substrate layer. The first transmission line is coupled to the first antenna by means of a second feed via.

Abstract: An apparatus for compensating for distortions in RF beams caused by a radome. The apparatus comprises: i) a plurality of metal patches arranged in rows and columns; ii) a first plurality of varactors coupling adjoining ones of a first plurality of metal patches in a first row of metal patches; and iii) a first reference voltage source configured to apply a first reference voltage to the first plurality of metal patches in the first row. The apparatus further comprises: iv) a second plurality of varactors coupling adjoining ones of a second plurality of metal patches in a first column of metal patches; and v) a second reference voltage source configured to apply a second reference voltage to the second plurality of metal patches in the first column. The first and second reference voltage sources adjust the phase delays of RF beams passing through each metal patch in the rows and columns.

Abstract: An antenna assembly for use in a tile architecture antenna system. The antenna assembly comprises: i) a first substrate layer having a first surface; ii) a first antenna disposed in an X-Y plane on the first surface of the first substrate layer; iii) a second substrate layer having a first surface, the second substrate layer displaced in the Z-direction with respect to the X-Y plane on the first surface of the first substrate layer; and iv) a first tuning balun disposed on the first surface of the second substrate layer and coupled to the first antenna by means of a first feed via. The antenna assembly further comprises a first transmission line disposed on the first surface of the second substrate layer. The first transmission line is coupled to the first antenna by means of a second feed via.

Abstract: An electronic system comprising: 1) an antenna; 2) a transmission line coupled to the antenna; 3) RF electronics circuitry coupled to the transmission line that is sensitive to a high frequency EMI/RF signal on the transmission line; and 4) a protection circuit comprising passive mode circuitry operational when the electronic system is powered off and active mode circuitry operational when the electronic system is powered on.

Abstract: An apparatus includes a plurality of layers of conductive elements and a substrate layer. A first of the layers of conductive elements has a first portion that includes conductive elements having a first structure different from a second structure of conductive elements in a second portion of the first layer. The first layer can be in contact with one side of the substrate layer. Conductive elements in a second of the layers of conductive elements can be in contact with another side of the substrate layer. The lens may include a first type of unit cell including at least one conductive element having the first structure and conductive elements having the second structure positioned on different sides of the substrate layer. The first type of unit cell may provide a capacitively-loaded bandpass filter response, and a second type of unit cell may provide a bandpass filter response.

Abstract: In a Multiple Input Multiple Output (MIMO) system, an apparatus and method includes a Tightly Coupled Array antennas (TCA) or Current Sheet Antennas (CSA). Far-field radiation patterns from any current sheet antenna are formed from the combination of the fields generated by a set of currents on the CSA of array port orthogonal modes, such as the Characteristic Modes (CM). The CM currents are generated by excitation of the CSA element ports with corresponding orthogonal voltages or currents (eigenvectors). Since the radiation patterns of the characteristic modes are orthogonal and uncorrelated, multiple signals may be propagated along the radiation patterns of the characteristic modes, each signal using a different characteristic mode or a different set of characteristic modes. Therefore, a CSA antenna utilizing array port orthogonal modes such as array port characteristic modes can support MIMO communications despite the strong mutual coupling among the antenna elements.

Abstract: An apparatus includes a plurality of layers of conductive elements and a substrate layer. A first of the layers of conductive elements has a first portion that includes conductive elements having a first structure different from a second structure of conductive elements in a second portion of the first layer. The first layer can be in contact with one side of the substrate layer. Conductive elements in a second of the layers of conductive elements can be in contact with another side of the substrate layer. The lens may include a first type of unit cell including at least one conductive element having the first structure and conductive elements having the second structure positioned on different sides of the substrate layer. The first type of unit cell may provide a capacitively-loaded bandpass filter response, and a second type of unit cell may provide a bandpass filter response.

Abstract: In a Multiple Input Multiple Output (MIMO) system, an apparatus and method includes a Tightly Coupled Array antennas (TCA) or Current Sheet Antennas (CSA). Far-field radiation patterns from any current sheet antenna are formed from the combination of the fields generated by a set of currents on the CSA of array port orthogonal modes, such as the Characteristic Modes (CM). The CM currents are generated by excitation of the CSA element ports with corresponding orthogonal voltages or currents (eigenvectors). Since the radiation patterns of the characteristic modes are orthogonal and uncorrelated, multiple signals may be propagated along the radiation patterns of the characteristic modes, each signal using a different characteristic mode or a different set of characteristic modes. Therefore, a CSA antenna utilizing array port orthogonal modes such as array port characteristic modes can support MIMO communications despite the strong mutual coupling among the antenna elements.

Abstract: An apparatus includes a lens having a plurality of layers of conductive elements and a plurality of layers of dielectric. Each of the layers of dielectric is disposed between and in contact with two of the layers of conductive elements. Different layers of conductive elements can include different numbers of conductive elements. The layers of conductive elements and the layers of dielectric can form a Cauer/Elliptic frequency selective surface. The lens could include only three layers of conductive elements and only two layers of dielectric, where the lens is a mixed-order frequency selective surface with a middle layer of conductive elements having fewer conductive elements than outer layers of conductive elements. A size of the conductive elements in at least one of the layers of conductive elements could vary as distance from a center of the lens increases.

Abstract: An improved wireless radio-frequency (RF) transmission system is disclosed. The wireless RF transmission system comprises: 1) a radio frequency (RF) transceiver configured to transmit and receive radio-frequency signals; ii) an electrically small antenna having a complex impedance comprising a real part and an imaginary part; and iii) a tunable negative impedance converter (NIC) circuit coupling the electrically small antenna to the RF transceiver. The tunable NIC circuit is configured to perform antenna matching by reducing the imaginary part of the complex impedance of the electrically small antenna. The tunable NIC circuit is tuned by adjusting a transconductance value associated with the tunable NIC circuit.

Abstract: An improved wireless radio-frequency (RF) transmission system is disclosed. The wireless RF transmission system comprises: 1) a radio frequency (RF) transceiver configured to transmit and receive radio-frequency signals; ii) an electrically small antenna having a complex impedance comprising a real part and an imaginary part; and iii) a tunable negative impedance converter (NIC) circuit coupling the electrically small antenna to the RF transceiver. The tunable NIC circuit is configured to perform antenna matching by reducing the imaginary part of the complex impedance of the electrically small antenna. The tunable NIC circuit is tuned by adjusting a transconductance value associated with the tunable NIC circuit.

Abstract: A system is configured to enable polarization alignment. The system includes at least one transmitter or receiver capable of polarization alignment. The transmitter includes at least one cross-polarized antenna and the receiver includes at least one cross-polarized antenna configured to receive a signal. A polarization processor in the transmitter or the receiver is configured to cause a polarization orientation of the at least one cross-polarized antenna to align with a polarization orientation of the signal.