One-of-many selection circuit for RF local-oscillator signal

Abstract

The invention discloses a one-of-many selection circuit for an RF local-oscillation signal. The one-of-many selection circuit is formed by sequentially connecting an amplitude-limiting active load circuit and a second differential switching circuit. The second differential switching circuit is formed by connecting a plurality of enabled first differential current switching circuit sets and an active load circuit in parallel. According to the one-of-many selection circuit, the function of selecting one local-oscillation signal from multiple local-oscillation signals can be achieved. A plurality of local-oscillation differential signals are converted into switching current signals with the same frequency through enabled first differential current switching circuits, current summation is achieved through output in parallel, and summated current is converted into a voltage signal through an active load circuit, then is converted into a current signal through a second differential current switching circuit, and then is converted into an amplitude-limiting differential local-oscillation signal through an amplitude-limiting active load circuit. By utilizing the one-of-many selection circuit, the function of one-of-many selection of the local-oscillation signals is achieved, an amplitude-limiting capacity is achieved, and the one-of-many selection circuit can provide appropriate-amplitude receiving local-oscillation signals and transmitting local-oscillation signals.

Description

technical field [0001] The invention relates to a multi-choice circuit for radio frequency local oscillation signals, and is particularly aimed at the problem of multi-channel local oscillation signals that have been generated in a multi-band radio frequency integrated circuit. Background technique [0002] With the promotion of the wireless electronic product market, radio frequency integrated circuits have developed faster and faster in recent years, and multi-mode / multi-frequency radio frequency integrated circuits have become an important demand in the industry. Radio frequency integrated circuits usually contain multiple module circuits, such as low noise amplifiers, mixers, filters, phase-locked loops, frequency synthesizers and other module circuits are important components of radio frequency integrated circuits. [0003] A notable feature of the multi-mode / multi-frequency radio frequency integrated circuit is that it can send and receive RF signals of different frequ...

AI Technical Summary

Problems solved by technology

[0006] An important problem that needs to be solved in the multi-choice circuit of the radio frequency circuit is the problem of radio frequency signal isolation. It is difficult for the radio frequency signal to achieve ideal switching characteristics in the integrated circuit. Coupling of the output through the branch to improve the isolation between channels

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