Design method of universal antenna array plane calibration module
By designing a universal calibration module and employing a specific DA chip and integrated RF SIP technology, the compatibility issues of the calibration module between different antenna arrays were resolved, the size and stability were optimized, signal isolation and power adaptation were achieved, and the system performance was improved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- NANJING RES INST OF ELECTRONICS TECH
- Filing Date
- 2026-02-03
- Publication Date
- 2026-05-01
AI Technical Summary
Existing calibration modules are not universally compatible across different antenna arrays, resulting in poor design compatibility, excessive size, increased risk of channel self-oscillation, signal leakage and backlash affecting system performance, and inability to meet the calibration requirements of different power arrays.
Design a universal calibration module that uses a specific DA chip to provide the local oscillator signal, integrates RF SIP technology, supports multiple operating modes, is compatible with different array systems, adopts time-division control of the DA to achieve up-conversion and direct transmission and sampling, uses high-power attenuators for graded attenuation, isolates signal crosstalk, and optimizes device layout.
The calibration module has been made universal, reducing size requirements, lowering the risk of channel self-oscillation, improving system stability and signal isolation, and meeting the calibration requirements of different power arrays.
Smart Images
Figure CN121966744A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of radio frequency microwave technology, specifically relating to the design technology of an array calibration module. Background Technology
[0002] When a phased array antenna is in operation, the amplitude and phase of a single channel need to be adjusted according to the required beam direction. Generally, a dedicated calibration module is used to calibrate and standardize the amplitude and phase.
[0003] Because antenna arrays have different operating mechanisms and methods, the calibration module needs to be customized according to the frequency generation method and the combined power of the array.
[0004] When antenna arrays are transmitting, some use a superheterodyne upconversion architecture to generate radio frequency (RF) signals, while others directly synthesize RF signals. When antenna arrays are receiving, some use a downconversion architecture to sample and process the signal, while others directly sample the signal. The differences in transmit power between different antenna arrays are even greater, resulting in varying power tolerance requirements for the calibration module.
[0005] The RF channel size of a conventional mixing system is approximately 20mm × 50mm, while that of a direct-transmission / direct-sampling system is approximately 20mm × 25mm. Based on the functional requirements of the calibration module, the number of channels is generally at least 8. In airborne and shipborne radar applications, the size requirements for modules are extremely stringent. Designing RF channels compatible with both mixing and direct-sampling using traditional methods results in large footprints that the platform cannot accommodate. The additional RF branches increase the risk of channel self-oscillation, and signal leakage and backlash introduce additional spurious signals, impacting system performance.
[0006] Currently, most calibration modules can only be used with specific antenna arrays and cannot be interchanged between different arrays, thus limiting their application. Designing a universal calibration module would alleviate the design pressure on antenna arrays. Summary of the Invention
[0007] This invention provides a universal calibration module design method for different antenna arrays. Compared with traditional design methods, an additional DA chip is added to generate the local oscillator signal, freeing the calibration module from dependence on an external local oscillator. It features multiple operating modes, compatible with different antenna array operating systems and modes. Attenuation design is implemented for high-power input signals to meet the calibration requirements of arrays with different power levels, improving the stability of the antenna array. The RF channel adopts integrated RF SIP technology, measuring 21.5mm × 24mm, and is divided into upper and lower layers, saving channel planar dimensions and isolating signal crosstalk.
[0008] The radar operates in pulse mode, with devices controlled according to timing commands. In transmit mode, the DA (Digital Converter) generates the local oscillator and intermediate frequency (IF) based on the transmit timing control signal. In receive mode, the DA typically does not operate; the control signal needs to be processed separately, inverted, and a time-division multiplexing control method is used to generate the local oscillator. To achieve synchronization, the radar array uses the same timing control signal. The DA's local processing of the timing signal introduces timing issues. During debugging, if this affects the system, delay compensation must be performed.
[0009] This invention employs a specific DA chip to provide the local oscillator signal, which is amplified, frequency-converted, and filtered within an integrated RF SIP channel. A parallel direct path is designed in the mixer link, switched by an RF switch to select different calibration module operating modes according to the requirements of different arrays. During array transmission, two operating modes are implemented: directly generating the signal or generating an up-converted signal. During array reception, two operating modes are implemented: directly sampling the signal or down-converting the signal for sampling.
[0010] When the calibration module is working, if up-conversion or down-conversion is performed, a specific DA will generate a local oscillator signal of the corresponding frequency. If direct transmission and sampling is performed, the specific DA will not work, thus realizing different signal generation and sampling methods.
[0011] In transmit-conversion mode, a specific DA generates a local oscillator signal, while other DAs generate intermediate frequency signals. The mixing path is selected in the RF link of the main and backup paths, and the amplification, up-conversion, filtering, and attenuation switching links are performed. The input is then used to the component to be calibrated to achieve the superheterodyne up-conversion mode.
[0012] In direct transmission mode, a specific DA generates an RF signal. A direct path is selected in the RF link of the main and backup paths, and the link is switched for amplification, filtering, and attenuation. The signal is then input to the component to be calibrated, thus achieving a direct signal generation mode.
[0013] In the receive-conversion operating mode, a specific DA generates a local oscillator signal, receives the radio frequency signal, passes through the attenuation switching link, selects the mixing path in the radio frequency link of the main and backup paths, and performs down-conversion with the local oscillator signal to generate an intermediate frequency signal, which is then sampled by the AD chip.
[0014] In direct sampling mode, the radio frequency signal is received, and after passing through the attenuation switching link, the direct path is selected in the radio frequency link of the main and backup paths for filtering and amplification, and then sampled by the AD chip.
[0015] The receiving link uses multiple high-power attenuators for graded attenuation, which attenuates the input high-power signal step by step to avoid excessive heat loss due to single-stage attenuation, meet the power requirements of the subsequent stage, reduce the pressure of thermal design, and increase the trace width and copper thickness of the RF printed circuit board before the attenuators to improve the current carrying capacity of the printed circuit board. Attached Figure Description
[0016] Figure 1 This is a block diagram illustrating the structural principle of the calibration module.
[0017] Figure 2 This is a block diagram of the primary and backup channel radio frequency link principle.
[0018] Figure 3 This is a block diagram illustrating the principle of attenuation switching link. Detailed Implementation
[0019] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings.
[0020] This invention uses a specific DA converter to generate a local oscillator, enabling two working modes: up-conversion and direct signal transmission and acquisition. A high-power attenuator is added to the receiving link to attenuate the input high-power signal, thus meeting the power tolerance requirements of the RF small signal link.
[0021] When the calibration module is working, such as Figure 1 As shown, if up-conversion or down-conversion is performed, a specific DA will generate a local oscillator signal of the corresponding frequency. If direct transmission and sampling is performed, the specific DA will not work. The module uses this to realize different signal generation and sampling methods.
[0022] In transmit-conversion mode, a specific DA generates the local oscillator signal, while other DAs generate the intermediate frequency (IF) signal. The mixing path is selected in the RF link of the primary / backup path, such as... Figure 2 As shown, the amplification, upconversion, filtering, and attenuation switching links are implemented, and the component to be calibrated is input to achieve the superheterodyne upconversion working mode.
[0023] In direct transmission mode, a specific DA generates an RF signal. A direct path is selected in the RF link of the main and backup paths, and the link is switched for amplification, filtering, and attenuation. The signal is then input to the component to be calibrated, thus achieving a direct signal generation mode.
[0024] In the receive-conversion operating mode, a specific DA generates a local oscillator signal, receives the radio frequency signal, passes through the attenuation switching link, selects the mixing path in the radio frequency link of the main and backup paths, and performs down-conversion with the local oscillator signal to generate an intermediate frequency signal, which is then sampled by the AD chip.
[0025] In direct sampling mode, the radio frequency signal is received, and after passing through the attenuation switching link, the direct path is selected in the radio frequency link of the main and backup paths for filtering and amplification, and then sampled by the AD chip.
[0026] The receive link design block diagram is as follows: Figure 3As shown, multiple high-power attenuators are used for graded attenuation, which attenuates the input high-power signal step by step, avoiding excessive heat loss caused by single-stage attenuation, meeting the power requirements of the subsequent stage, reducing the pressure of thermal design, and increasing the trace width and copper thickness of the RF printed circuit board before the attenuators to improve the current carrying capacity of the printed circuit board.
[0027] The above are embodiments of the present invention and do not limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention are included within the protection scope of the present invention.
Claims
1. A design method for a universal antenna array calibration module, characterized in that, include: A specific DA chip is used to provide the local oscillator signal, which is amplified, frequency-converted, and filtered in the integrated RF SIP channel. Parallel direct paths are designed in the mixer link and switched by an RF switch. Different calibration module operating modes are selected according to the requirements of different arrays. When transmitting from the array, two operating modes are implemented: directly generating the signal or generating an up-converted signal. When receiving from the array, two operating modes are implemented: directly sampling the signal or down-converting the signal for sampling.
2. The design method of the universal antenna array calibration module according to claim 1, characterized in that, When the calibration module is working, if up-conversion or down-conversion is performed, a specific DA will generate a local oscillator signal of the corresponding frequency; if direct transmission and sampling is performed, the specific DA will not work, thus realizing different signal generation and sampling methods.
3. The design method of the universal antenna array calibration module according to claim 2, characterized in that, The calibration module includes: a transmit frequency conversion working mode, in which a specific DA generates a local oscillator signal and other DAs generate intermediate frequency signals, selects a mixing path in the RF link of the main and backup paths, performs amplification, up-conversion, filtering, and attenuation switching links, inputs the component to be calibrated, and realizes the superheterodyne up-conversion working mode.
4. The design method of the universal antenna array calibration module according to claim 2, characterized in that, The calibration module includes: a direct transmission mode, in which a specific DA generates an RF signal, selects a direct path in the RF link of the main and backup paths, performs amplification, filtering, and attenuation switching links, inputs the component to be calibrated, and realizes the working mode of directly generating signals.
5. The design method of the universal antenna array calibration module according to claim 2, characterized in that, The calibration module includes: receiving a frequency conversion working mode, a specific DA generating a local oscillator signal, receiving a radio frequency signal, passing through an attenuation switching link, selecting a mixing path in the radio frequency link of the main and backup paths, down-converting the signal with the local oscillator signal to generate an intermediate frequency signal, and having the AD chip sample the intermediate frequency signal.
6. The design method of the universal antenna array calibration module according to claim 2, characterized in that, The calibration module includes: a direct sampling working mode, which receives radio frequency signals, passes them through an attenuation switching link, selects a direct path in the radio frequency link of the main and backup paths, performs filtering and amplification, and samples them by an AD chip.
7. The design method of the universal antenna array calibration module according to claim 1, characterized in that, Also includes: The receiving link uses multiple high-power attenuators for graded attenuation, gradually attenuating the input high-power signal. The trace width and copper thickness of the RF printed line are increased before the attenuators.