A Novel Active CMOS Polyphase Filter Circuit with High Image Rejection Ratio

Abstract

The invention belongs to the technical field of radio frequency receivers, and specifically relates to a novel active CMOS polyphase filter circuit with high image rejection ratio, I path, Q path, I path differential input voltage terminal, I path differential output end, and Q path differential Input voltage terminal, Q channel differential output terminal, power supply voltage VDD and MOS tube M 13 , M 14 , M 15 , M 16 , the I path includes a low-pass transconductance stage and a high-pass transconductance stage, which are respectively the first low-pass transconductance stage and the first high-pass transconductance stage; the Q path has a low-pass transconductance stage and a high-pass transconductance stage conduction stages, respectively including a second low-pass transconductance stage and a second high-pass transconductance stage. The present invention has lower power consumption, wider bandwidth and smaller chip area; Simultaneously the polyphase filter structure of the present invention effectively strengthens the matching of the pole frequency and the gain of high-pass and low-pass transfer functions; and the present invention The invention has the beneficial effect of wide application range.

Description

technical field [0001] The invention belongs to the technical field of radio frequency receivers, and in particular relates to a novel active CMOS polyphase filter circuit with high image rejection ratio. Background technique [0002] At present, the low-IF quadrature down-conversion architecture has been used as an excellent RF receiver topology to achieve highly integrated, high-performance, low-cost RF integrated circuits, and image interference has a significant impact on the final signal-to-noise ratio output to baseband. In order to achieve high selectivity between the desired signal and the image signal, this can be achieved by selecting a higher IF frequency and using an on-chip polyphase filter. Therefore, it is very necessary to design an on-chip polyphase filter with high performance, wide bandwidth and low power consumption. [0003] In most applications, polyphase filters are classified into passive polyphase filters and active polyphase filters. Several stage...

AI Technical Summary

Problems solved by technology

Most of the active polyphase filters discussed in the literature cannot achieve high operating frequency and low power consumption, especially some non-ideal factors in the circuit will affect the amplitude and phase of the high-pass transfer function and the low-pass transfer function, thereby limiting Image rejection ratio of polyphase filter

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