Abstract: A radiation detector is disclosed. The radiation detector is disposed on a microwave antenna assembly. The radiation detector includes a receiving antenna adapted to receive microwave energy. The receiving antenna includes a first tubular antenna member and a second tubular antenna member disposed concentrically about a longitudinal axis defined by the microwave antenna assembly. The detector also includes at least one rectifier coupled to the receiving antenna adapted to rectify at least a portion of the microwave energy and a filter coupled to the at least one rectifier and adapted to convert the rectified microwave energy into a detection signal.

Abstract: Methods and apparatus for determining parameters for an array are described. An exemplary embodiment of a method determines a set of parameters for an antenna array including multiple array elements, the array being fed by a feed array including a plurality of feed elements. The embodiment of the method includes measuring a plurality of bistatic ranges Rijk through different signal path combinations, each signal path combination from a feed element “i,” to an array element “j,” and to a feed element “k”. The measuring includes radiating energy from feed element “i”, and reflecting some of the radiated energy from array element “j” back to feed element k of the feed array. The measured bistatic ranges are processed to solve for the set of parameters.

Abstract: The present invention relates to a method of tuning a glass antenna that is capable of analyzing the sensitivity of each point, and forming a structure of a glass antenna by making use of a common simulation tool so as to perform tuning depending on a priority that is determined by data obtained by analyzing the sensitivity.

Abstract: Provided is a system and method for measuring an antenna radiation pattern in a Fresnel region based on a phi-variation method. The system includes a rotator for changing angles of a reference antenna and a target antenna; a vector network analyzer for obtaining radiation pattern data in accordance with transmission/reception radio frequency (RF) signals between the reference antenna and the target antenna; a measurement unit for calculating a far-field radiation pattern based on the radiation pattern data received from the vector network analyzer; and a controller for controlling the rotator according to a measurement angle transmitted from the measurement unit.

Abstract: A radiation detector disposed on a microwave antenna assembly to receive unintended field exposure in an insufflated abdomen. The radiation detector includes a receiving antenna made up of at least two pieces of metal externally attached to the microwave antenna within the abdomen. The radiation detector is adapted to receive errant microwave energy that resonates in the abdomen. A rectifier is coupled between the two pieces of metal, where the pieces of metal are strips, rings, patches, or other geometric combinations. The rectifier is adapted to rectify at least a portion of the errant microwave energy. A filter is coupled to the rectifier and is adapted to convert the rectified microwave energy into a detection signal. An inflatable stop is located on a distal end of the microwave antenna and the inflatable stop is inflated when inserted within the abdomen. The inflated stop prevents inadvertent removal of the microwave antenna.

Abstract: An embodiment of the present invention is an apparatus, comprising a tunable antenna including a variable reactance network connected to the antenna a closed loop control system adapted to sense the RF voltage across the variable reactance network and adjust the reactance of the network to maximize the RF voltage. The variable reactance network may comprise a parallel capacitance or a series capacitance. Further, the variable reactance networks may be connected to the antenna, which may be a patch antenna, a monopole antenna, or a slot antenna.

Abstract: A dynamic antenna pattern measurement method. Embodiments of the invention provide for nanosecond or better time resolution and milliradian angular resolution of the dynamic radiation pattern of an antenna under test over the predetermined solid angle scan (up to 4? steradians) of the dynamic radiation pattern.

Abstract: Conductive electronic device structures such as a conductive housing member that forms part of an antenna may be tested during manufacturing. A test system may be provided that has a pair of pins or other contacts. Test equipment such as a network analyzer may provide radio-frequency test signals in a range of frequencies. The radio-frequency test signals may be applied to the conductive housing member or other conductive structures under test using the test probe contacts. An antenna may be used to gather corresponding wireless radio-frequency signal data. Forward transfer coefficient data may be computed from the transmitted and received radio-frequency signals. The forward transfer coefficient data or other test data may be compared to reference data to determine whether the conductive electronic device structures contain a fault.

Abstract: Electronic devices may be provided that contain wireless communication circuitry. The wireless communication circuitry may include radio-frequency transceiver circuitry coupled to multiple antennas. An electronic device may alternate between a sleep mode and a wake mode. During wake mode, the electronic device may monitor a paging channel in a wireless network for incoming paging signals. The device may use a selected one of the multiple antennas in monitoring the paging channel. If received signal quality is satisfactory, the device may maintain use of the selected one of the multiple antennas for subsequent wake period monitoring of the paging channel. If received signal quality falls below a threshold or is otherwise indicated to not be satisfactory, the device may switch to use of a different one of the multiple antennas in monitoring the paging channel. Other criteria may also be used in controlling the switching between antennas for paging channel monitoring.

Abstract: An exemplary testing circuit board is used for testing an antenna performance and includes a signal circuit layer, a base layer electrically connected to the signal circuit layer, and a test unit. The signal circuit layer can transmit test signals from the antenna. The base layer is fixed with the signal circuit layer and used as a ground section to shield the test signals. The test unit is electrically connected to the signal circuit layer and the base layer and includes a signal inception port. The signal inception port is positioned on the signal circuit layer and protrudes from the base layer, and the signal inception port is capable of receiving the test signals and transmitting the test signals to the signal circuit layer.

Abstract: A controlled power supply comprising: a) an array of low voltage current sources; b) a plurality of switch power supplies coupled to each of the storage capacitors and respective ones of the pulse loads being coupled to each of the switch power supplies; c) each of the storage capacitors being configured for storing energy during an inactive portion of a load switching cycle of the respective switch power supply to which the corresponding storage capacitor is coupled when the pulse loads are inactive; d) a respective output capacitor in association with each of the switch power supplies for feeding voltage to the respective pulse loads during an active portion of the load switching cycle; and e) the respective storage capacitor being configured for supplying the stored energy via the respective to the respective switch power supply to which the storage capacitor is coupled to each of the pulse loads coupled to switch power supply during an active portion of the load switching cycle.

Abstract: An electromagnetic wave measuring apparatus includes: a reception antenna receiving an electromagnetic wave generated from an electronic apparatus placed at a predetermined distance away; an antenna mast holding the reception antenna; and a base portion fixing an end of the antenna mast vertically to a floor, the base portion having a flat bottom surface opposed to the floor, the bottom surface and the floor forming a gap of 2 mm or less therebetween and being capacitively coupled to each other. The base portion includes a mast-fixing portion having a height of 45 mm or less vertically to the floor and fixing the end of the antenna mast, a power portion being disposed at a position away from the reception antenna and generating power, and a power transmission portion transmitting the power generated by the power portion to the reception antenna and vertically moving the reception antenna along the antenna mast.

Abstract: A method and apparatus for determining the attenuation of an RF signal caused by a DPF at an unknown or different ambient temperature than the temperature used for DPF sensor calibration is disclosed. The method and apparatus determine the sensor attenuation just prior to determining the DPF attenuation by disconnecting the antennas and determining the attenuation of a loopback path. This sensor attenuation can then be deducted from the attenuation determined for the normal path that includes the attenuation caused by the loopback path, the cables, and the DPF. This method compensates for variation in the attenuation of the sensor caused by changes in ambient temperature of the sensor. Further temperature compensation is be achieved by determining additional factors to account for variations caused by changes in ambient temperature.

Abstract: Disclosed is a method of measuring the radiation characteristic of an antenna, where sufficient power is secured within a short period of time and supplied in a stable manner so as to always keep the intensity of measurement signals high irrespective of the measurement frequency. With the antenna radiation measurement method, upon receipt of measurement frequency signals, location information and measured values are processed to transmit measurement signals, and a charging high frequency of several hundred megahertz (MHz) to several hundred gigahertz (GHz) is scanned toward a tester body such that inductive power is generated to allow the self-charging. The measurement frequency signals are transmitted toward the tester body through a source antenna, and the measured signals transmitted from the measurement antennas of the respective measurement modules are received and data-processed at a measurement controller.

Abstract: A radio frequency(RF) printed circuit board (PCB) includes an RF circuit for generating high frequency signals. The RF PCB is connected to an EMC measuring device when measuring the EMC thereof. The measuring device includes a probe pin and a shielding barrel surrounding the probe pin. The shielding barrel includes an end surface at a distal end thereof. The RF PCB further includes a test node connected to the RF circuit and a ground node surrounding the test node. The test node contacts the probe pin and outputs the high frequency signals when measuring the EMC of the RF PCB. The ground node corresponds to the end surface and contacts the end surface while the probe pin contacts the test node.

Abstract: A system for enabling the wireless use and billing for that use of any of a wide variety of different manufacturers personal, ground-position-indicating enabled, wireless electronic rf communication devices in a zone, and a network outside of the zone.

Abstract: A method and device provides for the testing and validation of a control module for receiving wireless data and communications utilizes a transmission line coupler mounted proximate the control module generates a signal that couples to an antenna of the control module. The control module produces a signal in response to coupling of the antenna with the signal produced by the transmission line coupler. The resulting signal is utilized to check, verify and validate operation of the control module.

Abstract: A RF signal test and measurement system capable of measuring forward and reverse signal parameters of RF components including Electrically Small Antennas (ESA) and capable of being integrated within a communications system to aid the automatic retuning of antennas.

Abstract: A system for testing a communications device includes a portable wireless communications device comprising a transmitter for transmitting an RF signal. A monitoring device receives the RF signals from the portable wireless communications device and analyzes the RF signals to determine total radiated power emitted from the transmitter. An adaptive antenna equivalent circuit is coupled to the transmitter. A connection line extends between the adaptive antenna equivalent circuit and the monitoring device. The adaptive antenna equivalent circuit has an equivalent antenna impedance matched to the portable wireless communications device and the connection line and monitoring device based on transmit frequency to ensure that total radiated power of the RF signals is transmitted from the transmitter to the monitoring device.

Abstract: The present invention concerns an active electronically scanned array antenna comprising: an active array, configured for radiating/receiving radiofrequency signals through first radiating openings that lie on a ground plane; and a dielectric cover arranged at a given distance from the ground plane so that between said dielectric cover and said ground plane an air gap is present. Said active electronically scanned array antenna is characterized in that it further comprises one or more calibration devices operable for calibrating said active electronically scanned array antenna, each calibration device comprising a respective radiating portion arranged between the dielectric cover and the ground plane and configured for receiving radiofrequency signals radiated through corresponding first radiating openings and for radiating radiofrequency signals in the air gap towards said corresponding first radiating openings.

Abstract: A measured antenna and a measuring antenna are placed inside a radio anechoic container. On the basis of an aperture size D of the measured antenna, an aperture size d of the measuring antenna, and a wavelength ? of a measurement frequency, a distance L between the measured antenna and the measuring antenna is set to a value in the range of (D+d)2/(2?) to 2(D+d)2/?. Thus, in the Fresnel region where the distance L is short, antenna characteristics of the measured antenna substantially the same as those in the Fraunhofer region where the distance L is long can be measured.

Abstract: Disclosed is a method for predicting a phase pattern using a magnitude pattern in near-field or Fresnel field formed by antenna radiation, including: determining a first parameter group including a first actual distance between a source antenna and a probe and the magnitude pattern at the first distance; assuming a second parameter group including a second distance that is an effective distance between the source antenna and the probe, a current magnitude distribution of the source antenna and a current phase distribution of the source antenna, based on the first parameter group; calculating the magnitude pattern at the first distance based on the second parameter group; and determining the phase pattern at the first distance when the magnitude pattern at the calculated first distance matches with the magnitude pattern at the first distance included in the first parameter group by the comparison therebetween.

Abstract: An embodiment of the present invention an apparatus, comprising an apparatus, comprising an adaptively-tuned antenna including a variable reactance network connected to the antenna, an RF field probe located near the antenna, an RF detector to sense voltage from the field probe, a controller that monitors the RF voltage and supplies control signals to a driver circuit and wherein the driver circuit converts the control signals to bias signals for the variable reactance network.

Abstract: Systems and methods are described for simulating an internal antenna within a telemetry device. The simulator device includes a housing having at least one opening, wherein the housing is configured to accommodate close proximity placement of the telemetry device. The simulator device also includes a simulator or test antenna within the housing that corresponds to an internal antenna within a housing of the telemetry device. The simulator device further includes a radio frequency (RF) connector coupled to the simulator housing, for connection to a communication device. The simulator device also includes a fastening mechanism to secure the simulator device over the telemetry device so that the simulator antenna is adjacent to the internal antenna. The proximity of the simulator antenna to the internal antenna provides simulator device RF characteristics that simulate internal antenna RF characteristics.

Abstract: A feed structure for a radio frequency antenna, comprising: a plurality of radio frequency antenna elements; and a plurality of detectors, each one of the detectors being coupled to a corresponding one of the radio frequency antenna elements. Each one of the detectors is responsive to optical frequency energy to produce input radio frequency power for the corresponding one of the antenna elements coupled to said one of the detectors.

Abstract: A testing method of a multiband antenna is provided. The testing method includes the following steps. Firstly, whether a testing angle of a multiband antenna is less than a default value is determined, and if the testing angle is less than a default value, then the testing frequency is set equal to a first default frequency according to the frequency table so as to obtain a first testing result corresponding to the first default frequency when the multiband antenna is at the testing angle. Next, whether the testing frequency needs to be changed is determined, and if the testing frequency needs to be changed, then the testing frequency is set equal to a second default frequency according to the frequency table so as to obtain a second testing result corresponding to the second default frequency when the multiband antenna is at the testing angle.

Abstract: A method for determining at least one characteristic of an antenna requiring: a) positioning an antenna in a space surrounded by a waveguide; b) feeding an electric excitation signal (utx(t)) into a feed connection of the waveguide; c) receiving the electric response signal (urx(t)) emitted by the antenna resulting from the excitation signal (utx(t)); d) determining at least one characteristic of the antenna from a portion of the response signal (urx(t)) and a corresponding portion of the excitation signal (utx(t)), where the portion of the response signal (urx(t)) is evaluated in the time domain and satisfies the following conditions: (i) only one or more waves of the electromagnetic field caused by the excitation signal (utx(t)) and running from the feed connection towards the antenna exist at the location of the antenna; and (ii) the electromagnetic field at the location of the antenna is a TEM field.

Abstract: A method is provided for estimating the polarization ellipticity of an antenna response signal to an incident electromagnetic wave received on a crossed-loop antenna or an Adcock antenna array. The method comprises at least the following steps: measuring the phase offset ?? between the signals acquired respectively on the cosine and sine path of the antenna; measuring the ratio R between the amplitudes of the signals acquired respectively on the cosine and sine path of the antenna; determining the ellipticity angle ? based on the phase offset ?? and on the ratio R. The invention applies notably to the discrimination of ionospheric waves from ground and/or sea waves, in particular for a surveillance, eavesdropping, or goniometry system using HF band signals.

Abstract: Structures and methods for a tunable waveguide radiating element are disclosed. The waveguide radiating element comprises a rectangular tube, which includes partially filled dielectric slabs that are disposed on parallel planes and incident on a lower edge of the element's mouth. The faces of each slab are engraved with a number of concentric SRR squares that present a gap on one of its sides. The distance between any two consecutive slabs may vary. The gaps of the outmost square may be arranged in such a way that, on the facing sides of two adjacent slabs, the gaps are rotated with respect to each other.

Abstract: A test system for testing multiple-input and multiple-output (MIMO) systems is provided. The test system may convey radio-frequency (RF) signals bidirectionally between a base station emulator and a device under test (DUT). The DUT may be placed within a test chamber during testing. An antenna mounting structure may surround the DUT. Multiple antennas may be mounted on the antenna mounting structure to transmit and receive RF signals to and from the DUT. A first group of antennas may be coupled to the base station emulator through downlink circuitry. A second group of antennas may be coupled to the base station emulator through uplink circuitry. The uplink and downlink circuitry may each include a splitter, channel emulators, and amplifier circuits. The channel emulators and amplifier circuits may be configured to provide desired path loss and channel characteristics to model real-world wireless network transmission.

Abstract: A gyroscope monitoring system operates with an antenna system that has a gyroscope that controls the position of multiple antennas. The monitoring system receives data indicating reference signal strengths and test signal strengths for the antennas. The monitoring system determines differences between the reference signal strengths and the test signal strengths. The monitoring system processes the differences to determine if the gyroscope has lost reference point accuracy, and if so, then the monitoring system generates an indication that the gyroscope has lost reference point accuracy. In some examples, the monitoring system also determines reference point offsets for the gyroscope and provides the offsets to the gyroscope for use in motion measurements.

Abstract: A first adjustment circuit adjusts an impedance of a first antenna, and a second adjustment circuit adjusts an impedance of a second antenna. A coupling reduction circuit reduces an amount of coupling of the first and second antennas. A first reception power measurement unit measures first reception power received from the first antenna, and a second reception power measurement unit measures second reception power received from the second antenna. A selection unit selects a circuit from among the first adjustment circuit, the second adjustment circuit, and the coupling reduction circuit. A circuit control unit controls the impedance of the selected circuit so that the value of the evaluation function proportional to the product of the first reception power and the second reception power becomes larger.

Abstract: Systems and methods of testing active digital radio antennas are presented. Systems and methods can test the active digital radio antenna functioning as both a radio and as an antenna and can test both the transmit and receive performance of the antenna. An electromagnetic probe can scan the antenna to perform the testing and couple to the elements of the antenna using radio frequency signals propagated in the air, as opposed to direct cabling.

Abstract: A system and method for antenna analysis and electromagnetic compatibility testing in a wireless device utilizes a “parent” device that undergoes rigorous conventional testing. A “child” device having similar components may thereafter undergo abbreviated testing. Because the Total Isotropic Sensitivity of the parent device is known, testing may be performed on the child device to infer equivalence to the parent's TIS performance using the abbreviated test techniques.

Abstract: An antenna system includes plural antennas. Each antenna is different than every other antenna. Each antenna is characterized by a principal plane. A principal plane of a first antenna is oblique to a principal plane of a second antenna. The first antenna includes a first insulating substrate extending in the principal plane of the first antenna. The first antenna further includes a first radiating element and a connected first conductor and includes a second radiating element and a connected second conductor. The first antenna further includes a coupling conductor coupling the second radiating element and the first conductor. The first antenna further includes a first coupler having a first signal conductor and a second signal conductor. The first signal conductor is coupled to the second conductor, and the second signal conductor is coupled to the first radiating element.

Abstract: A narrow band, tunable antenna uses a series of small inductors wired in series to produce different resonant frequencies from a single antenna across a wide frequency spectrum. Radio Frequency (RF) switches are positioned in parallel with the inductors and are capable of shunting a selected inductor out of the antenna circuit thereby changing the electrical length of the antenna and consequently, the resonant frequency. The RF switch control circuitry is isolated from the RF current in the antenna.

Abstract: An object is to provide a semiconductor device capable of preventing an alternating leakage current from flowing into a voltage detection circuit. The semiconductor device includes an antenna circuit, a resonance frequency regulating circuit, a voltage detection circuit, and a first capacitor. The resonance frequency regulating circuit includes a second capacitor including one terminal electrically connected to a first terminal of the antenna circuit; and a transistor including a first terminal electrically connected to the other terminal of the second capacitor, a second terminal electrically connected to a second terminal of the antenna circuit, and a gate electrically connected to the first capacitor and the voltage detection circuit.

Abstract: A front end module for a wireless transmission/reception device has two antennas and two signal paths connected thereto. A mismatch in the antenna is identified by monitoring the transmitted power and the reflected power in the active and passive signal paths and using the powers in a controller to generate a control signal for the antenna tuner. In this case, decreasing isolation between the first and second antennas and the first and second signal paths is identified, and is compensated for using different devices, in order to ensure faster and safer antenna matching.

Abstract: A composite dipole array assembly can have a composite dipole array defined by a plurality of antenna elements and a plurality of non-linear element electrically interconnecting pair of the antenna elements. A reflector can be configured to reflect electromagnetic energy toward the antenna elements. A lens can be configured to focus electromagnetic energy upon the antenna elements. In this manner, the efficiency of the composite dipole array is enhanced.

Abstract: Provided is a technique capable of accurately calculating the radiation power of an object to be measured using a spheroidal coupler even when there is a non-negligible loss in a measurement system. A phase rotating unit including a variable phase shifter, a two-branch circuit, and a reflective element that is connected to one of the branched outputs of the two-branch circuit is inserted between a receiving antenna and a power measuring device. The maximum value and the minimum value of power measured by a power measuring device when the variable phase shifter changes a phase are calculated. An output reflection coefficient of a coupler is calculated from the ratio of the maximum value to the minimum value, and an input reflection coefficient of an object to be measured which is approximate to the output reflection coefficient is estimated. In addition, an input reflection coefficient of a reference antenna which is used instead of the object to be measured is estimated in the same way.

Abstract: A test device for testing high frequency electromagnetic interference (EMI), the test device includes a measuring body and a probe device. The probe device includes a horn antenna, a handle, and a cable. The horn antenna detects high frequency EMI. The handle is attached to the horn antenna for feasibly holding the horn antenna. A first end of the cable is connected to the horn antenna, and a second end of the cable is connected to the measuring body.

Abstract: There is provided an antenna characteristic measuring system which includes a measuring point scanner to scan a measuring point, an antenna gain measuring device which measures an antenna gain of a measured antenna at a plurality of the measuring points, determines a reference point among the plurality of the measuring points, and obtains antenna gain difference values between the antenna gain at the reference point and each of the antenna gain at the plurality of the measuring points other than the reference point, and an antenna characteristic measuring device which measures a reference antenna characteristic of the measured antenna at the reference point and obtains an antenna characteristic of the measured antenna at each of the plurality of the measuring points other than the reference point by correcting the reference antenna characteristic with each of the difference values.

Abstract: A method of determining reference signal received power (RSRP) by user equipment (UE) associated with a distributed antenna system (DAS) may include detecting at least three different reference signals in one or more common reference signals (CRSs) that are associated with different antennas in the DAS. The method may also include determining at least three different RSRPs corresponding to the at least three different reference signals. The at least three different RSRPs may be level 3 filtered to produce at least three corresponding filtered powers. The UE may report a maximum of the at least three corresponding filtered powers to the distributed antenna system.

Abstract: Disclosed are an impedance matching method, an impedance matching apparatus for the same, and a record medium. The impedance matching apparatus includes a storage part to store information about an impedance matching point according a state of an obstacle, an impedance matching part connected to an antenna and including at least one variable element, a detector to detect transmit power and reflected power reflected by the antenna, and a controller to search for an impedance matching point within a variation range of the variable element by using at least one of the transmit power and the reflected power, and to detect a state of a surrounding obstacle by comparing information about the searched impedance matching point with the stored information about the impedance matching point.

Abstract: Disclosed are an impedance matching method, an impedance matching apparatus for the same, and a record medium. The impedance matching apparatus includes an impedance matching part connected to an antenna to transmit/receive a radio wave and including at least one variable capacitor, a detector to detect transmit power and reflected power reflected by the antenna, and a controller to set a first searching region within a whole variation range of the variable capacitor, to detect an optimal impedance matching point within the first searching region by using at least one of the transmit power and the reflected power, and to set a next searching region about the optimal impedance matching point to search for a final impedance matching point within the whole variation range of the variable capacitor.

Abstract: A sensor that senses incident RF signals is provided. The sensor is capable of sensing signals in the Gigahertz (GHz) and Terahertz (THz) range. The sensor may utilize one or more cantilevers, an interferometer, or may be formed in a box-type configuration.

Abstract: Methods and systems for determining insertion loss for a mast clamp current probe (MCCP) coupled to a monopole antenna are disclosed. An exemplary method includes determining a first power radiated by the monopole antenna across a first range of frequencies while driving the monopole antenna using a base-feed arrangement to produce a first power-frequency measurement, determining a second power radiated by the monopole antenna across the first range of frequencies while driving the monopole antenna using an MCCP-feed arrangement to produce a second power-frequency measurement and to determine impedance mismatch (MM), and determining insertion loss using the first power-frequency measurement, the second power-frequency measurement and the impedance mismatch.

Abstract: A method of matching a receive-only antenna (60) for use in receiving video signals in which measurements made on a transceiver's antenna (14) when in an transmitting mode are used in matching the receive-only antenna. The ratio of the amplitude of the reflected signal to the strength of the transmitted signal strength is used not only in selecting components for matching the transceiver's antenna (14) but also in selecting components for matching the receive-only antenna (60). The ratio may be applied to respective look-up tables (54, 64) for selecting the components to be used in matching the respective antennas.

Abstract: A method for calibrating an array antenna having a plurality of branches includes generating a test signal using a pseudo-random sequence assigned to one of the plurality of branches for each of the plurality of branches; adding the test signals to a useful signal of the antenna so as to form a summed signal emitted via the array antenna; receiving the summed signal with a receiver antenna; correlating the received summed signal with a replica of the pseudo-random sequence so as to produce a correlation result; estimating a characteristic of one of the plurality of branches by processing the correlation result; and calibrating the antenna based on the estimated characteristic.

Abstract: The present invention relates to antenna calibration for active phased array antennas. Specifically, the present invention relates to a built-in apparatus for autonomous antenna calibration. Accordingly, the present invention provides an antenna array comprising: a plurality of antenna elements forming an array face and a plurality of calibration antennas mounted around the array face. The plurality of calibration antennas comprising one or more pairs. The calibration antennas have overlapping coverage areas such that the entire array face of the antenna array is within the coverage area of at least one calibration antenna and each pair of calibration antennas have overlapping coverage areas such that of a common area of the array face is within both coverage areas.