A terrestrial high frequency data communication system and method for implementing a pointing algorithm for endpoint nodes are described. The system includes an aggregation node and one or more endpoint nodes. In one example, a pointing direction for an endpoint node is determined based on a number of packet error rate (PER) measurements associated with a high frequency data communication link between the endpoint node and an aggregation node. Preferably, the endpoint node includes a steerable antenna module that includes one or more antennas. The steerable antenna module is configured to receive an azimuth value and an elevation value determined based on PER measurements associated with the high frequency data communication link, and to steer its one or more antennas based on the azimuth value and the elevation value to point to the aggregation node.

An antenna apparatus may be disclosed. The antenna apparatus may include a feed network including a plurality of first internal transmission lines arranged in a cross form and a plurality of second internal transmission lines arranged in a ring form around the plurality of first internal transmission lines; and a plurality of radiation elements positioned around the feed network and radiating signals fed by the feed network.

A system includes a direct radiating array antenna and one or more processors. The antenna includes an array of elements configured to radiate radiofrequency (RF) energy to form a beam having multiple frequency channels. The one or more processors are configured to generate an excitation plan for powering the elements to form the beam. The excitation plan assigns multiple corresponding beamforming coefficients to each element in a group of the elements. Each beamforming coefficient designates power allocated to the assigned element for radiating RF energy at an associated frequency channel. The excitation plan provides a substantially uniform power distribution among the elements in the group, and at least some of the elements in the group have different allocations of power among the multiple frequency channels of the beam than other elements in the group.

A system includes a direct radiating array antenna and one or more processors. The antenna includes an array of elements configured to radiate radiofrequency (RF) energy to form a beam having multiple frequency channels. The one or more processors are configured to generate an excitation plan for powering the elements to form the beam. The excitation plan assigns multiple corresponding beamforming coefficients to each element in a group of the elements. Each beamforming coefficient designates power allocated to the assigned element for radiating RF energy at an associated frequency channel. The excitation plan provides a substantially uniform power distribution among the elements in the group, and at least some of the elements in the group have different allocations of power among the multiple frequency channels of the beam than other elements in the group.

A fastener accessory includes a fastener body and a sacrificial radio frequency (RF) tag. A dielectric substrate of the tag is affixed to a contact surface of the fastener body. An RF antenna trace is connected to or printed on the substrate. The antenna trace transmits an RF response signal when energized by an external RF tracking circuit. The substrate is plastically deformed by an installation force to prevent transmission of the response signal. A method for locating the fastener body within a search area includes exciting a receiver trace of the tag using an interrogation signal, frequency-modulating an interrogation frequency using an RF modulating circuit, transmitting a response signal at a response frequency via a transmitting antenna trace of the tag, and detecting the response signal using an RF tracking circuit to locate the fastener body within the search area.

A fastener accessory includes a fastener body and a sacrificial radio frequency (RF) tag. A dielectric substrate of the tag is affixed to a contact surface of the fastener body. An RF antenna trace is connected to or printed on the substrate. The antenna trace transmits an RF response signal when energized by an external RF tracking circuit. The substrate is plastically deformed by an installation force to prevent transmission of the response signal. A method for locating the fastener body within a search area includes exciting a receiver trace of the tag using an interrogation signal, frequency-modulating an interrogation frequency using an RF modulating circuit, transmitting a response signal at a response frequency via a transmitting antenna trace of the tag, and detecting the response signal using an RF tracking circuit to locate the fastener body within the search area.

An electrically scanned array antenna device applied to a millimeter wave imaging system is provided. The electrically scanned array antenna device comprises an adjustable light source for outputting an optical signal with an adjustable wavelength; an electro-optical modulation module; an optocouple; a time delay module for performing optical delay of different duration on each modulated signal, and correspondingly changing the duration of the optical delay according to the wavelength of the optical signal to obtain modulated signals of different phases; an optical detector; and an array antenna. The millimeter wave is loaded on the optical signal with an adjustable wavelength to obtain a modulated signal; the modulated signal is divided into multiple signals; time delay of different duration is performed on each signal; and millimeter wave signals of different phases are obtained after demodulation and are simultaneously transmitted to scan an object to be measured.

An electrically scanned array antenna device applied to a millimeter wave imaging system is provided. The electrically scanned array antenna device comprises an adjustable light source for outputting an optical signal with an adjustable wavelength; an electro-optical modulation module; an optocouple; a time delay module for performing optical delay of different duration on each modulated signal, and correspondingly changing the duration of the optical delay according to the wavelength of the optical signal to obtain modulated signals of different phases; an optical detector; and an array antenna. The millimeter wave is loaded on the optical signal with an adjustable wavelength to obtain a modulated signal; the modulated signal is divided into multiple signals; time delay of different duration is performed on each signal; and millimeter wave signals of different phases are obtained after demodulation and are simultaneously transmitted to scan an object to be measured.

A terrestrial high frequency data communication system and method for implementing a pointing algorithm for endpoint nodes are described. The system includes an aggregation node and one or more endpoint nodes. In one example, a pointing direction for an endpoint node is determined based on a number of packet error rate (PER) measurements associated with a high frequency data communication link between the endpoint node and an aggregation node. Preferably, the endpoint node includes a steerable antenna module that includes one or more antennas. The steerable antenna module is configured to receive an azimuth value and an elevation value determined based on PER measurements associated with the high frequency data communication link, and to steer its one or more antennas based on the azimuth value and the elevation value to point to the aggregation node.

A terrestrial high frequency data communication system and method for implementing a pointing algorithm for endpoint nodes are described. The system includes an aggregation node and one or more endpoint nodes. In one example, a pointing direction for an endpoint node is determined based on a number of packet error rate (PER) measurements associated with a high frequency data communication link between the endpoint node and an aggregation node. Preferably, the endpoint node includes a steerable antenna module that includes one or more antennas. The steerable antenna module is configured to receive an azimuth value and an elevation value determined based on PER measurements associated with the high frequency data communication link, and to steer its one or more antennas based on the azimuth value and the elevation value to point to the aggregation node.