Filter circuit, automatic tuning circuit, filter adjusting circuit and adjusting method

Abstract

The invention discloses a filter circuit, an automatic tuning circuit, a filter adjusting circuit and an adjusting method. The filter circuit is simple and reasonable in structural design, can reduce the occupied area of a chip, has a multi-channel selection function, and can meet the requirements of high broadband gain, low power consumption and the like at the same time. The filter circuit structure comprises a third-order reconfigurable gm-c complex band-pass filter circuit, a reconfigurable bias circuit structure, an automatic tuning circuit structure and an integral structure, wherein the automatic tuning circuit is connected with the third-order reconfigurable gm-c complex band-pass filter through the reconfigurable bias circuit; the integral structure automatic tuning circuit is used for generating a resistor array control word to control the reconfigurable biasing circuit, and the reconfigurable biasing circuit is used for generating bias voltage used by the third-order reconfigurable gm-c complex band-pass filter. The invention further discloses a method for adjusting the center frequency and bandwidth of a third-order reconfigurable gm-c complex band-pass filter by applying a reconfigurable biasing circuit structure and an automatic tuning circuit.

Description

technical field [0001] The invention relates to the technical field of filters, in particular to a filter circuit, an automatic tuning circuit, a filter adjusting circuit and an adjusting method. Background technique [0002] At present, in the radio frequency transceiver system, commonly used radio frequency transceiver structures mainly include zero-IF structure and low-IF structure. There is no image signal in the zero-IF structure receiver, but there are 1 / f noise and DC offset and other problems. The IF filter is a low-pass filter with simple circuit and low power consumption. Therefore, low-IF is usually used in narrowband communication. structure, the intermediate frequency filter can filter out the image interference signal after mixing in the receiving system, and at the same time it needs to perform channel selection in multi-channel standards, so a reconfigurable complex bandpass filter with channel selection function can be used in the low intermediate frequency ...

AI Technical Summary

Problems solved by technology

[0004] Aiming at the problems in the prior art that the filter structure is complex, the included resistors and capacitors occupy a large chip area, and it is difficult to obtain a large bandwidth due to the limitation of power consumption, or it is easy to generate large power consumption, the present invention provides a filter The device circuit structure and its method, its structural design is simple and reasonable, can reduce the area occupied by the chip, and has a multi-channel selection function, which can meet the requirements of high broadband gain and low power consumption at the same time

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