High-gain and high-isolation millimeter wave double-balance passive subharmonic mixer

Abstract

The invention discloses a high-gain and high-isolation millimeter-wave double-balanced passive subharmonic mixer, which includes an active balun radio frequency input stage, a passive balun local oscillator input stage, a passive subharmonic mixing stage and Transimpedance output stage. The active balun amplifies the RF signal and the local oscillator differential signal generated by the passive balun for sub-harmonic mixing, and outputs an intermediate frequency signal through the transimpedance amplifier. In the mixing stage, the local oscillator signal is injected from the source of the transistor, and the radio frequency signal is injected from the gate to improve the conversion gain. The active balun is based on the cascode differential pair structure, adding cross-coupling tubes to improve the amplitude and phase consistency. The transimpedance amplifier uses the cross-coupling structure to enhance the gain, reduce the input and output impedance, improve the input current amplification capability and output drive capability, and further increase the conversion gain. The passive subharmonic mixer has the characteristics of high conversion gain and high port isolation, and is suitable for single-ended input and differential output mixing applications.

Description

technical field [0001] The invention relates to a passive mixer, specifically a high-gain and high-isolation millimeter-wave double-balanced passive subharmonic mixer, which can be used for mixing the front-end radio frequency signals of Ka-band integrated receivers, and belongs to microwave radio frequency receivers technology field. Background technique [0002] The sub-harmonic mixer uses the second harmonic of the local oscillator signal to mix with the RF signal. The frequency of the local oscillator signal is only half of the frequency of the local oscillator signal of the fundamental mixer, which greatly reduces the design of the local oscillator signal source. Difficulty and cost, so it is more suitable for microwave frequency band. Active subharmonic mixers are based on traditional Gilbert units, but put forward special requirements for local oscillator signals, requiring four-phase quadrature local oscillator signals or other more complex structures. In contrast, ...

AI Technical Summary

Problems solved by technology

Baluns are divided into passive baluns and active baluns: passive baluns have the advantages of good symmetry and simple structure, but there is a natural 3dB loss; active baluns can provide a certain gain and are compact in size, but due to Parasitic effects of active devices, limiting the increase in operating frequency

Common active baluns include common sourc

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