A receiver RF front-end processing circuit and receiver based on direct sampling

Abstract

The invention discloses a receiver radio frequency front-end processing circuit based on direct sampling and a receiver. The receiver radio frequency front-end processing circuit includes a control circuit, and the control circuit is respectively connected with a channel selection module, an attenuation module, a preselection filter group module and an amplification module. connected; a channel selection module, which receives radio frequency signals and self-test signals, and under the control level generated by the control circuit, selects radio frequency signals or self-test signal outputs; an attenuation module, which is used to generate Under the action of the control level of the channel selection module, the signal output by the channel selection module is quantitatively attenuated; the pre-selection filter group module includes a switching filter bank of a channel in the form of a square matrix, which is used to receive the control level generated by the control circuit to select the corresponding frequency band The filtering channel realizes the pre-selection filtering of the quantitatively attenuated signal; the amplification module is used for quantitatively amplifying and outputting the pre-selection filtering signal under the action of the control level generated by the control circuit.

Description

technical field [0001] The invention belongs to the technical field of receiver radio frequency front-end processing, and in particular relates to a receiver radio frequency front-end processing circuit and a receiver based on direct sampling. Background technique [0002] The RF front end of the receiver is an important part of the receiver, which determines the key performance indicators such as the receiver's sensitivity, noise figure, second-order intercept point, and third-order intercept point. The receiver can be divided into superheterodyne type, zero-IF type, image suppression type and digital IF type according to different topological structures. In addition, the input RF signal can also be directly sampled by AD to become a digital signal and then digital The signal is processed. [0003] The existing superheterodyne receiver first pre-filters the received radio frequency signal, then mixes it to a fixed intermediate frequency, and finally controls the gain of th...

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Problems solved by technology

[0006] This scheme has a problem with shortwave receivers that receive and analyze shortwave signals with a frequency of 3MHz to 30MHz: since there is no attenuation module at the front end of the receiver, the maximum allowable input power is limited; the frequency range of received signals is 3MHz to 30MHz, for The lower frequency signal of 3MHz cannot be received and analyzed normally; after the RF front-end signal is amplified twice, the linearity is limited by the two-stage amplifier

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