Frequency selecting filter for configurable bandwidths and configurable frequency points and implementation method thereof

Abstract

The invention discloses a frequency selecting filter for configurable bandwidths and configurable frequency points. The frequency selecting filter comprises an operational transconductance amplifier OTA at a signal amplification and conversion front end, an adjustable input resistor Rin and an adjustable output resistor Rout, an adjustable transconductance operational amplifier array, an adjustable capacitor array and a control voltage output module, wherein the OTA realizes transconductance adjustability and the filter can be in cascade connection with the rear of arbitrary circuit without considering impedance matching; the adjustable input resistor Rin and the adjustable output resistor Rout are used for meeting the requirement of the interior of the filter for the impedance matching; the adjustable transconductance operational amplifier array realizes configurable frequency points of the filter; the adjustable capacitor array realizes configurable bandwidths of the filter; the control voltage output module is used for providing a control voltage required by the OTA; the adjustable transconductance operational amplifier array, the switch tube and the capacitor array are matched with one another. The frequency selection of a wireless communication system does not depend on a frequency mixer any longer, the defect that a specific chip is only used for a specific system is overcome, the filtering and frequency selecting functions are integrated, and a majority of frequency points and bandwidths applied to a wireless communication private network are covered.

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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