A structure of image rejection mixer suitable for terahertz band

Abstract

The invention belongs to the technical field of terahertz devices, and provides an image frequency suppression mixer structure suitable for terahertz bands, including an E-plane rectangular waveguide cross-shaped branch line bridge 3dB directional coupler, microstrip waveguide double probes, two A mixer and a power combiner; the RF signal passes through the E-plane rectangular waveguide Tian-shaped branch line bridge 3dB directional coupler to generate two RF signals with equal amplitude and 90 degree difference, which are respectively input into the two mixers; The vibration signal passes through the microstrip waveguide double probes to generate two signals of equal amplitude and same phase, which are respectively input into the two mixers; the intermediate frequency output signals of the two mixers are output after power synthesis by the power combiner; the power combiner A 90-degree phase shifter is set at the front end of the input terminal, so that the corresponding intermediate frequency output signal of one mixer generates a 90-degree phase shifter, so that the intermediate frequency output signals of the two mixers are superimposed and output in phase. The invention provides an image frequency suppression mixer with simple structure and suitable for terahertz band.

Description

technical field [0001] The invention belongs to the technical field of terahertz devices, and relates to an image frequency suppression mixer, in particular to an image frequency suppression mixer structure applicable to the terahertz band. Background technique [0002] THz waves refer to electromagnetic waves with a frequency in the range of 0.1-10THz (wavelength 0.03mm-3mm). Its long-wave band coincides with microwave and millimeter waves, and its short-wave band coincides with infrared rays. Its special position in the electromagnetic wave spectrum determines It combines some of the advantages of microwave and millimeter waves and light waves, that is, the advantages of stronger directionality of wave speed, higher resolution, and larger information capacity. Therefore, terahertz waves are widely used in many fields such as radar communication, object imaging, and environmental monitoring. [0003] In application systems such as terahertz communication, radar, and electr...

AI Technical Summary

Problems solved by technology

[0004] The suppression of the image frequency usually adopts the method of adding an image frequency suppression filter at the input end of the mixer. However, in the terahertz frequency band, the frequency of the radio frequency signal is much higher than the frequency of the intermediate frequency signal. If this method is used, the filter involved The center frequency is very high and the bandwidth is very narrow, which greatly increases the difficulty of filter design

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