Frequency conversion channel circuit of small-sized airborne upconversion system

Abstract

The invention discloses a frequency conversion channel circuit of a small-sized airborne upconversion system. The frequency conversion channel circuit comprises a frequency mixer, a band-pass filter, an amplifier, a numerical control attenuator, a low-pass filter, a wave detection output circuit, a fault processing circuit and a power supply processing and module enable circuit. After externally-input 70MHz signals and signals output by a local oscillate circuit are subjected to frequency mixing, required wideband signals are generated firstly through double frequency conversion, and then, signals with the frequency of 960-1224 MHz are output through filtering and amplifying. According to the frequency conversion channel circuit of the small-sized airborne upconversion system, a digital phase-locked frequency source is directly adopted, the frequency mixer with higher compression is selected and used for frequency spectrum shift, and thus, the spurious suppression ratio of a system is greatly improved; and the double frequency conversion is adopted, so that the spur is effectively suppressed, and the anti-interference capacity is improved.

Description

technical field [0001] The invention relates to a small airborne up-conversion system frequency conversion channel circuit. Background technique [0002] There are many ways to achieve frequency hopping oscillation, which can be divided into direct synthesis (crystal oscillator frequency multiplication chain) and indirect synthesis (phase-locked loop) according to the way of realization. When direct synthesis is used, the system is complex in structure, high in cost, low in clutter suppression, difficult to achieve dense jump points, large in working current, and large in size; in indirect synthesis, although the system is simple in structure, high in reliability, low in cost, High wave suppression, easy to achieve dense jump points, small operating current, and small size, but it must be combined with direct synthesis when forming broadband frequency hopping, and the slow frequency hopping speed and poor phase noise are inevitable shortcomings . At present, the frequency ...

AI Technical Summary

Problems solved by technology

It has the advantages of relatively simple system composition, low cost, and small volume. Because it uses indirect synthesis, its clutter suppression is good and the complexity is not high.

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