Ultra-wideband high-stability IQ modulator circuit and modulation method

Abstract

The invention provides an ultra-wideband high-stability IQ modulator circuit. A carrier signal is firstly input through an IN port, and is divided into two paths of signals after being processed by aninput amplifier unit, wherein one path of signals pass through an R-C network of a channel 1, and the other path of signals pass through a C-R network of a channel 2, and thus the carrier signal is divided into two paths of signals which have a phase difference of 90 degrees at a 90-degree phase shifter consisting of the R-C network and the C-R network, and the signals of the channel 1 and the channel 2 are separately amplified through a channel amplifier unit, are separately mixed with a baseband signal I and a baseband signal Q at a mixing unit, are amplified through an output amplifier unit, and then are combined through an output wideband balun to output an IQ modulation signal. According to the scheme of the invention, the wideband 90-degree phase shifter implemented by the R-C network and the C-R network is small in circuit size and can be integrated on a monolithic integrated circuit; and vector modulation errors can be reduced, and the quality of vector modulation signals canbe improved.

Description

Technical field [0001] The invention relates to the technical field of testing, in particular to an ultra-wideband high-stability IQ modulator circuit, and also relates to an ultra-wideband high-stability IQ modulation method. Background technique [0002] IQ modulators are widely used in radar, communication, and measurement fields. Vector modulation error (EVM) is an important indicator to measure the quality of IQ modulated signals. This indicator is mainly determined by the quadrature error index and gain balance index. Reduce the quadrature error to obtain high Quality IQ modulation signal is a difficult point in IQ modulation technology. Quadrature error is affected by three aspects: 90° phase shifter accuracy, channel phase consistency, and phase temperature drift. [0003] In narrowband applications such as radar and communications, high-precision 90° phase shifting, higher channel phase consistency, and phase temperature drift compensation can be achieved to obtain modulat...

AI Technical Summary

Problems solved by technology

[0011] In order to solve the problem of large quadrature error and temperature drift of quadrature error in the existing broadband IQ modulator, the present invention proposes an ultra-wideband high-stability IQ modulator circuit and modulation method, thereby reducing the vector modulation error and improving the modulation signal quality

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