Array Antenna Self-Calibration via Signal Feedback
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Solution Overview
Problem
Existing array antenna calibration methods are limited, as they require dedicated areas and are not applicable to transmission/reception array antennas or planar arrays, and fail to properly correct amplitude and phase fluctuations in complex antenna configurations.
Innovation Solution
An array antenna device with integrated transmission/reception circuits that can self-calibrate by using a transmission/reception controller to correct amplitude and phase fluctuations through interconnection amplitude-phase information, eliminating the need for external calibration antennas and equipment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If calibration is conducted using an anechoic chamber and measuring instrument, then measurement precision is improved, but device complexity and cost increase
Solution Approach 1:
The array antenna device performs self-calibration by having each element antenna sequentially transmit signals and other element antennas receive and feed back the signals. The controller processes the received signals to calculate reception characteristics and determines correction coefficients without requiring external calibration equipment, thus achieving self-service calibration.
Solution Approach 2:
The invention introduces a signal as an intermediary medium to transfer calibration information between element antennas. By having element antennas transmit and receive signals sequentially, the calibration information is conveyed through the signal itself rather than requiring direct measurement equipment connection to each antenna element.
2Measurement precision
If calibration-use antennas are set up separately from the array antenna, then measurement precision is improved, but ease of operation deteriorates due to dedicated area requirements
Solution Approach 1:
The invention merges the calibration function with the array antenna device itself by using the element antennas of the array antenna as both the calibration targets and the calibration tools. Each element antenna serves dual purposes: being calibrated and performing calibration on other elements, eliminating the need for separate calibration-use antennas and dedicated calibration areas.
Solution Approach 2:
The element antennas are designed to be multi-functional, serving both as the array antenna elements for normal operation and as calibration-use antennas for self-calibration. This universality allows the same antenna structure to perform multiple functions without requiring additional dedicated calibration equipment.
3Device complexity
If calibration method from Patent Literature 1 is used, then device complexity is reduced, but adaptability deteriorates as it is limited to linear array antennas
Solution Approach 1:
The controller is designed to universally handle different array antenna configurations by implementing a general calibration algorithm that works for both linear arrays and planar arrays. The signal transmission and reception process remains the same regardless of the specific geometric arrangement of element antennas, making the calibration method adaptable to various configurations.
Solution Approach 2:
The invention extends the calibration method from one-dimensional linear arrays to two-dimensional planar arrays by maintaining the same fundamental signal transmission and reception mechanism. The controller adapts the calibration process to accommodate the additional spatial dimension in planar configurations without requiring fundamentally different calibration approaches.
Data Source
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AI summary
Provided is an array antenna device including: a plurality of element antennas (100); a transmission/reception module (200), which is to be connected to one of the plurality of element antennas (100), and includes a transmission circuit (TC), a reception circuit (RC), and a transmission-reception switching switch (231, 232) ; a transmission/reception controller (500) configured to perform control by controlling an amplitude and phase of a signal passing through the transmission circuit (TC) and the reception circuit (RC) in each transmission/reception module (200), and by switching between transmission and reception; a distributor (310) configured to distribute a signal from a signal transmitter to each transmission circuit (TC) to transmit a distributed signal from the each transmission circuit (TC); a combiner (410) configured to combine a signal received by each reception circuit (RC); and a receiver (400) configured to receive the combined signal. In the array antenna device, a detection signal, which contains a detected amplitude and phase of the signal received by the receiver, is corrected with a piece of interconnection amplitude-phase information about a space between the element antennas (100) to obtain a calibration value in calibration of each transmission/reception module (200), and calibration is conducted based on the calibration value.