High-speed switching radio frequency receiving channel group delay consistency method

Abstract

The invention discloses a high-speed switching receiving radio frequency channel group delay consistency method, and aims to provide a group delay consistency method which is universal, stable, reliable and small in distortion. The method is realized through the following technical scheme: in a receiving channel group time delay consistency circuit, customizing a microwave radio frequency switch meeting time and reliability requirements of high-speed switching receiving radio frequency channel group time delay consistency, and controlling switching time errors and switching time of the microwave radio frequency switch to be consistent; when the signal passes through the channel first-stage mixer, setting any one received signal frequency to be converted to a middle filter center frequencypoint through a local oscillator frequency mixing rate; using an MCU to send a multi-channel high-speed switching control command and a second pulse control command to a synchronous signal processingunit through an I/O direct control line; and the time of the channel state switching control command arriving at all control switches being consistent, so that the signal on-off time difference between channels caused by the time difference of the control command is reduced, and the channel delay consistency is improved.

Description

technical field [0001] The invention relates to a method that can be directly applied to a rotating interferometer to switch radio frequency receiving channel group time delay consistency at high speed. Background technique [0002] After the broadband signal passes through the transmission equipment, due to the different responses of the transmission equipment to the various spectral components of the signal, it will cause the phase relationship disorder of the various spectral components of the signal at the output of the equipment due to different phase shifts or time delays, that is, phase distortion. Measure this characteristic The index of is the group delay. For linear frequency modulation signals, the group delay causes the phase difference to increase with the increase of the frequency. Since the group delay more intuitively represents the delay of the group signal, it is an important parameter to measure the influence of the transmission network on the signal trans...

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Problems solved by technology

[0005] The positioning system of the rotating interferometer requires high-speed switching of the RF receiving channel to accumulate the phase difference of the antenna baseline. Tens of thousands of switching times require the back-end processing equipment to collect and accumulate the signal phase of the receiving channel for as long as possible within a single switching time. The processor has no time to wait for a single switching state, and the signal amplitude and phase of the signal are incomplete during the switching time, which cannot be used as the estimated data for the accumulation of the phase mean square value. Therefore, in the high-speed switching state, the switching between multiple channels The influence of device switching time, filter sideband group delay and channel control command delay on channel group delay consistency cannot be ignored

At present, in radar phased arrays, measurement and control electronic equipment, and other commonly used receiving electronic equipment, channel group delay consistency is mainly achieved by circuit design layout symmetry, and for asymmetrical parts, transmission line phase equalization is used for phase matching. Stable, no high-speed switching, symmetrical circuit design layout, phase matching of transmission line phase equalization can solve the channel group delay consistency in most steady-state working conditions, but for high-speed channel switching in transient state, due to Its switching speed reaches the μs level. Not only the group delay consistency between channels in a relatively stable working state must be considered, but also the device delay in a transient state and the influence of signal crosstalk between channels on broadband signal phase synthesis must be considered. Therefore, the channel group delay consistency method that only considers the symmetry of the design layout has certain limitations

Moreover, transmission line phase compensation technology, due to the characteristics of the transmission line and the uncertainty of electromagnetic coupling after the miniaturized structure of the circuit design, its phase compensation does not change ideally linearly with the frequency, and there is also a certain phase error when performing phase compensation synthesis. The use of transmission line phase compensation will Increase the space transmission path of electromagnetic signals. When the space transmission path increases, the probability of space coupling also increases, and the risk of amplitude distortion also increases. Therefore, the design of symmetrical layout and the stability and reliability of the transmission line phase compensation method also have certain defects.

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