Programmable/adjustable active electric resistance-capacitance wave filter and radio communication system

A resistance-capacitor, active technology, applied in the direction of frequency selection two-terminal-to-network, multi-terminal-to-network, etc., can solve the problems of increasing the number of components, reducing the control efficiency, and limited application scope.

Inactive Publication Date: 2009-10-14
IND TECH RES INST
View PDF6 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In this way, the number of components on the circuit will increase, the control efficiency will decrease, and it will also cause problems in the design

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Programmable/adjustable active electric resistance-capacitance wave filter and radio communication system
  • Programmable/adjustable active electric resistance-capacitance wave filter and radio communication system
  • Programmable/adjustable active electric resistance-capacitance wave filter and radio communication system

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0034] The following description of the circuit of the present invention does not include the complete circuit structure of the active filter. The prior art used in the present invention is only cited here in an emphatic manner to help explain the present invention. Moreover, the relevant drawings in the following texts are not drawn to scale, and their function is only to show the structural features of the present invention.

[0035] image 3 Shown is an embodiment of the present invention, the filter circuit utilizes a differential amplifier D having a double-ended input and a double-ended output Amp , resistance R f , R i , R t and capacitor C. In this example the difference amplifier D Amp It is a double-ended input and double-ended output element, so the circuit is symmetrical up and down. The equivalent resistance R of the filter can be obtained by using the small signal analysis method of the active filter e and cut-off frequency Fcut for:

[0036] ...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

No PUM Login to view more

Abstract

A programmable/adjustable active low-pass filter for analog circuits, wherein a controllable shunt device is implemented by utilizing the linearity of field effect transistors. A linear analysis of the transfer function of the filter circuit shows that the cut-off frequency of the filter can be changed by determining the equivalent small-signal current through the controllable shunt device. Therefore, when the cut-off frequency is shifted due to changes in the circuit process or environmental parameters (such as temperature), the filter allows the user to continuously fine-tune the cut-off frequency by controlling the controllable shunt device to make the cut-off frequency can still maintain the original frequency value. In addition, different applications require different cutoff frequencies, the present invention also provides a method that can greatly change the cutoff frequency, and the cutoff frequency can be adjusted to the desired frequency value according to different application conditions, so that the same filter circuit Can be widely used for various purposes.

Description

technical field [0001] The invention relates to an analog filter circuit, in particular to a resistor-capacitor filter and a wireless communication system capable of fine-tuning and changing the cut-off frequency and gain of an active filter. Background technique [0002] A filter is a common and important unit in a signal processing system. Its function is to eliminate unwanted frequency band signals to retain or amplify required frequency band signals. In the advanced integrated circuit manufacturing process, it is a common trend to integrate the filter into the chip, especially in the communication market. With the continuous evolution and progress of the communication system, the signal processing circuit not only requires high-standard performance on the one hand, but also on the other hand. , it is often required to be able to switch and process signals of two systems in the same circuit at the same time; for example, the second / third generation (2nd / 3rd Generation) mo...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
IPC IPC(8): H03H11/04
Inventor 楼志宏陈弘易
Owner IND TECH RES INST
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap