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CN-121995123-A - Chip antenna phase center alignment method

CN121995123ACN 121995123 ACN121995123 ACN 121995123ACN-121995123-A

Abstract

The invention discloses a chip antenna phase center alignment method, which belongs to the technical field of chip antennas and comprises the steps of pre-scanning a phase pattern of a chip antenna by using a scanning frame, judging the position offset of the phase center and an actual scanning center by using obtained phase pattern data, so as to adjust the position of a scanning center, determining the position of the antenna phase center by simulation before testing, and establishing a coordinate system by referring to the phase center obtained by simulation during testing. The center alignment method of the invention confirms the position of the actual phase center by developing a phase pattern pre-scanning technology, thereby ensuring the accuracy of data which need to be obtained through spherical scanning, such as far-field patterns, spherical near-field amplitude phase data and the like, solving the problem that the chip antenna cannot confirm the phase center through a simple geometric position, and solving the problem that the chip antenna is difficult to calibrate the phase center due to the factors of the structure, the size and the like compared with the existing test flow.

Inventors

  • FAN BOHAO

Assignees

  • 北京无线电计量测试研究所

Dates

Publication Date
20260508
Application Date
20251226

Claims (6)

  1. 1. A method for aligning the phase center of a chip antenna, the method comprising: The scanning frame is used for pre-scanning the phase pattern of the chip antenna, and the position offset of the phase center and the actual scanning center is judged according to the obtained phase pattern data, so that the position of the scanning center is adjusted; When the chip antenna to be tested meets far-field conditions, the complex antenna with any size is replaced by a simple point source at a sufficiently far observation position.
  2. 2. The method of claim 1, wherein the definition of the phase center is partially weakened under the condition of meeting the engineering application, the approximate phase center meeting the engineering application requirement is found, and if a point for flattening the phase distribution of the main lobe of the antenna exists, the point is defined as the "apparent phase center" of the antenna.
  3. 3. The method of claim 2, wherein the apparent phase center is defined as two points different from each other: A "main lobe" focusing on phase information within the main lobe without regard to phase information of the full spatial range; The phase distribution is flattest, smaller fluctuation is allowed to exist in the phase distribution on the premise of meeting application requirements, and the difference value between the maximum value and the minimum value of the constraint phase is within a certain interval or the variation quantity of the maximum value and the minimum value of the constraint phase is minimum.
  4. 4. A method for aligning a phase center of a chip antenna according to claim 3, wherein before testing the antenna to be calibrated, it is ensured that a rotation center of the mechanical arm coincides with a phase center of the antenna, and whether a scanning center of the mechanical arm coincides with the phase center is determined by determining a phase-angle curve during pre-scanning by using a mechanical arm pre-scanning technique.
  5. 5. The method for aligning the phase center of a chip antenna according to claim 4, wherein the mechanical arm pre-scanning technique specifically operates as follows: Selecting a measured surface of an antenna, positioning the scanning center of the mechanical arm to the phase center of the chip antenna to be measured, taking the direction of the antenna port surface as 0 degrees, controlling the mechanical arm to scan the measured surface of the antenna by an angle of-20 degrees to 20 degrees, reading the phase information at the moment, and drawing a far-field phase pattern.
  6. 6. The method of claim 5, wherein the far-field phase pattern is as follows: The phase is sequentially lagged in the scanning range, the receiving antenna needs to be moved leftwards, and the adjustment position is continuously measured after the receiving antenna is moved leftwards until a flat phase diagram is obtained; The phase is advanced in turn in the scanning range, and the receiving antenna needs to be moved rightwards; The phase is firstly lagged and then advanced in the scanning range, and the phases of symmetrical points are consistent, so that the receiving antenna needs to be moved to the direction close to the chip antenna; The phase is advanced and then delayed in the scanning range, and the phases of the symmetrical points are consistent, so that the receiving antenna needs to be moved in the direction away from the chip antenna; the center and the phase center are offset from left to right, up and down, the phase curve obtained by scanning is fitted once, the primary component of the curve is separated to serve as the left offset and the right offset of the scanning center and the phase center, then the up and down offset of the scanning center and the phase center is obtained by analyzing and subtracting the trend of the primary fitting line, and the alignment work of the scanning center of the mechanical arm and the phase center of the chip antenna is completed.

Description

Chip antenna phase center alignment method Technical Field The invention belongs to the technical field of chip antennas, and particularly relates to a chip antenna phase center alignment method. Background The chip antenna adopts a CMOS technology to integrate an antenna flow sheet on a wafer and an integrated circuit in the wafer, and reduces a signal transmission link compared with a traditional planar antenna, so that the chip antenna has the advantages of low high-frequency loss, high integration level, small volume and the like, and is widely applied to the fields of array radars, satellite communication, remote sensing and the like. The characteristic that the absorption of the atmosphere to wireless signals reaches a peak value in a frequency band of about 60GHz is generally utilized, the safety and the anti-interference performance of the chip antenna for transmitting electromagnetic communication signals in a short distance are guaranteed, a two-dimensional phased array chip antenna for satellite communication exists in the prior art, 4096 nano antennas are integrated on a silicon substrate, and the size of the chip is only one needle point. Chip antennas are usually very small in area due to their structure unlike antennas of a common feeding type, and for antennas of microstrip type usually employed for on-chip antennas, the phase center thereof is difficult to determine by a simple calibration geometric center. Even if the position of the phase center is obtained by simulation, the phase center is offset due to factors such as manufacturing accuracy, dielectric constant difference of the substrate, and thickness. In addition, the area is extremely small, and for 300GHz wavelength, the calibration of the phase center at least needs to be more than two tenth of wavelength, namely more than 0.05mm, so that the accuracy of phase test can be basically ensured. Therefore, the phase center of the chip antenna is extremely difficult to accurately calibrate through instrument and equipment before testing, even the phase center deviation under different frequency points is far away, and therefore, before actual testing, the position of the phase center of the antenna needs to be determined through simulation, and a coordinate system is established by referring to the phase center obtained through simulation during the actual testing. The foregoing is not necessarily a prior art, and falls within the technical scope of the inventors. Disclosure of Invention In order to solve the above problems, an object of the present invention is to provide a chip antenna phase center alignment method, which confirms the position of the actual phase center by developing a phase pattern pre-scanning technique, thereby ensuring the accuracy of data, such as far field pattern, spherical near field amplitude phase data, etc., which need to be obtained by spherical scanning, and solving the problem that the chip antenna cannot confirm its phase center by a simple geometric position. In order to achieve the above object, the present invention provides a method for aligning the phase center of a chip antenna, the method for aligning the phase center of the chip antenna comprising: And pre-scanning the phase pattern of the chip antenna by using a scanning frame, and judging the position offset of the phase center and the actual scanning center by the obtained phase pattern data, thereby adjusting the position of the scanning center. When the chip antenna to be tested meets far-field conditions, the complex antenna with any size is replaced by a simple point source at a sufficiently far observation position. Preferably, under the condition of meeting engineering application, the definition of the phase center is partially weakened, the approximate phase center meeting engineering application requirements is found, and if a point for enabling the phase distribution of the main lobe of the antenna to be flattest exists, the point is defined as the 'apparent phase center' of the antenna. Preferably, the apparent phase center is defined as two different points: A "main lobe" focusing on phase information within the main lobe without regard to phase information of the full spatial range; The phase distribution is flattest, smaller fluctuation is allowed to exist in the phase distribution on the premise of meeting application requirements, and the maximum and minimum value difference of the constraint phase is within a certain interval or the variation quantity of the constraint phase is minimum. Preferably, before testing the antenna to be calibrated, the rotation center of the mechanical arm is ensured to be coincident with the phase center of the antenna, and whether the scanning center of the mechanical arm is coincident with the phase center is judged by judging a phase-angle curve during pre-scanning by utilizing the mechanical arm pre-scanning technology. Preferably, the mechanical arm pre-scanning technology specifically opera