Ka-band millimeter-wave harmonic direct modulator

Abstract

The invention provides a Ka frequency band millimeter wave harmonic direct modulator, aiming at providing a broadband direct modulator which is high in carrier suppression, wide in working band, good in stability, and applicable to high speed transmission of millimeter waves. The modulator is achieved by the following technical scheme which comprises that two baseband signals I, Q are fed into two completely same multiplying units via a baseband signal I input end and a baseband signal Q input end respectively, a microwave signal is divided into two paths through same-phase power dividing by a microwave power divider (23), one path is fed to a first harmonic multiplying unit after being fed into a phase shifter via the first power dividing end of the power divider for phase shifting for 45 degrees, and the other path is directly fed into a second harmonic multiplying unit via the second power dividing end of the power divider; the two baseband signals I, Q respectively pass through a first low-pass filter with a baseband signal I input end and a second low-pass filter with a baseband signal Q input end, and are respectively multiplied by second harmonics of a carrier signal in the two multiplying units, thus a modulated signal is output through being added in a same-phase way by a millimeter wave power divider.

Description

technical field [0001] The invention relates to a modulator mainly used in the communication field of various platforms and used for Ka frequency band millimeter wave direct modulation. Background technique [0002] With the advent of the information age, people's demand for multimedia broadband services is increasing day by day. However, for wireless communication systems that are currently short of spectrum resources, they can no longer adapt to current changes. With the development of high capacity and transmission rate, millimeter wave frequency band resources become the first choice for future broadband communication. The millimeter-wave direct modulator, which has the characteristics of wide working bandwidth and can realize large data and high-speed data transmission, just meets this demand. [0003] At present, the millimeter-wave direct modulator that can be used in Ka-band miniaturized satellite communication equipment has the problems of carrier leakage and I / Q c...

AI Technical Summary

Problems solved by technology

Among them, the IQ multiplier based on the fundamental wave is in the Ka frequency band. Due to the increase of the frequency band, the shortening of the wavelength, and the high requirements for circuit processing accuracy, the carrier leakage of the fundamental wave IQ multiplier is relatively high, which cannot meet the needs of engineering applications. The 0 / π modulator of the phase switch can only realize the modulation method of BPSK, and the frequency band utilization rate is relatively low, which is not suitable for high-speed transmission of large data

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