Broadband high-precision active phase shifter

Abstract

The invention belongs to the field of design of radio-frequency microwave integrated circuits, and in particular relates to a broadband high-precision active phase shifter. The phase shifter mainly comprises an orthogonal signal generator, a quadrant selection switch, a VGA and an output BUFFER. The phase shifter disclosed by the invention does not adopt the traditional orthogonal signal amplitude adjusting method, namely control of the signal amplitude by change of bias current; but, the phase shifter disclosed by the invention adopts a method for synthesizing the needed amplitude by controlling a series of sub-gain units through a switch; therefore, the problem that the phase shifting accuracy is decreased due to the fact that the linearity of a MOS transistor in the traditional phase shifter is limited can be solved; simultaneously, design of a complex high-bit DAC also can be avoided; in addition, the quadrant selection switch of the phase shifter also has the amplification function, and has the inhibiting effect on a noise coefficient; the load of the common-source amplifier in the output BUFFER of the phase shifter is adjustable; and thus, the in-band flatness of signals can be adjusted.

Description

technical field [0001] The invention belongs to the field of radio-frequency microwave integrated circuit design, and in particular relates to a broadband high-precision phase shifter used in a multifunctional transceiver assembly, which can be used in related phased array systems such as wireless communication, radar detection, and electronic countermeasures. Background technique [0002] As the core component of the active phased array system, the broadband active phase shifter has a decisive impact on the performance of the active phased array system. Its index directly determines the technical standard of the phased array system, and its weight and volume directly Affecting the miniaturization of the phased array system, its reliability and cost determine the application prospect of the phased array system. Due to the large number of phase shifters equipped in a phased array system, we should reduce the volume and weight of its components as much as possible and control ...

AI Technical Summary

Problems solved by technology

The usual phase shifter mostly adjusts the quadrature signal amplitude by controlling the bias current of the VGA. The disadvantage of this structure is that when the precision of the phase shifter is high, a bias current with a very large variation range is required. On the one hand, it is difficult to accurately generate a bias current with such a large variation range; on the other hand, when the variation range of the bias current is relatively large, limited by the linearity of the MOS tube, the gain of the VGA will also deviate from the expected value, shifting The phase accuracy decreases, making it difficult to design a phase shifter with higher precision, and this is the primary problem that the new phase shifter needs to solve

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