A frequency-selective filter with configurable bandwidth and configurable frequency point and its realization method

Abstract

The invention discloses a frequency-selective filter with configurable bandwidth and configurable frequency points. Impedance matching; adjustable input resistance R in and adjustable output resistor R out , used to meet the requirements for impedance matching inside the filter; adjustable transconductance operational amplifier array, to achieve configurable filter frequency points; adjustable capacitor array, to achieve configurable filter bandwidth; control voltage output module, used to provide transconductance The control voltage required by the conductance operational amplifier; wherein, the adjustable transconductance operational amplifier array, the switch array and the capacitor array are matched one by one. The invention can make the frequency selection of the wireless communication system no longer only depend on the mixer, overcome the defect that a specific chip can only be used for a specific system, integrate the filtering and frequency selection functions, and cover the application of the wireless communication private network Most frequencies and bandwidths.

Description

technical field [0001] The invention relates to a frequency selection filter for general wireless broadband communication, in particular to a frequency selection circuit with configurable bandwidth and configurable frequency points, which is used for frequency selection of signals in the field of wireless broadband radio frequency communication. Background technique [0002] The modern wireless communication receiving system receives wireless signals from the base station, and completes data reception and processing through a series of steps such as amplification, frequency mixing, filtering, and analog-to-digital conversion. Most of the wireless signal frequency selection is done through the mixer. It down-converts the signal generated by the local oscillator and the received signal to generate a zero-IF signal, and then filters out the noise through a low-pass filter, the operational amplifier (Op-Amp) amplifies the signal, and the analog-to-digital converter (A / D conversi...

AI Technical Summary

Problems solved by technology

[0003] However, at present, there are many kinds of frequencies and bandwidths used by private networks in my country's wireless communication industry, and their frequencies are mainly concentrated in the range of 100MHz to 1.2GHz, and each private network uses different frequencies, RF bandwidths, and signal bandwidths (5kHz to 2MHz). Unite

Since specific mixers cannot cover all frequency points and signal bandwidths, the RF chips used by private network equipment in various industries are different. At the same time, the demand for RF front-end chips is difficult to form a scale effect, and the cost is high and matching is difficult.

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