Looking for breakthrough ideas for innovation challenges? Try Patsnap Eureka!

Feedforward filter using translational filter

A feed-forward filter and filter technology, applied in the field of feed-forward filters, can solve problems such as difficult to realize low-cost small filters

Inactive Publication Date: 2016-06-08
MEDIATEK INC
View PDF6 Cites 1 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, these features are difficult to achieve in low-cost, low-power, and small filters with conventional architectures

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
  • Feedforward filter using translational filter
  • Feedforward filter using translational filter
  • Feedforward filter using translational filter

Examples

Experimental program
Comparison scheme
Effect test

Embodiment approach A

[0037] In embodiment A, a feedforward filter with high out-of-band rejection is provided. This feedforward filter consists of a main path and a feedforward path. In-band signals generated by the main path will be preserved, and out-of-band signals or interference will be removed by the feed-forward path. Thus, a bandpass filter with high out-of-band rejection is realized.

[0038] refer to Figure 6A and Figure 6B , Figure 6A and Figure 6B Embodiment A according to the present invention illustrates a block diagram and a detailed implementation of the feedforward filter 300 . Feedforward filter 300 includes a first path 310 and a second path 320 . The input signal S_IN is sent to the first path 310 and the second path 320 . The first path 310 and the second path 320 generate a first output S_F1 and a second output S_F2 respectively. The signal subtractor 330 combines the first output S_F1 and the second output S_F2 to generate a filtered signal S_Filtered.

[0039] ...

Embodiment approach B

[0045] Figure 8 Embodiment B of the present invention is illustrated. In this embodiment, the first path 410 and the second path 420 included in the feedforward filter 400 are respectively driven by local oscillation signals having different frequencies. The first path 410 comprises a first translating filter 412 having a plurality of filter branches, the number of filter branches of the first translating filter 412 depending on the content of the signal S_IN. The filter branch of the first translation filter 412 consists of the same frequency f A and local oscillation signals LOA1 to LOAN of different phases are driven separately. The number of filter branches of the second translation filter 414 is the same as the number of filter branches of the first translation filter 412, but the filter branches of the second translation filter 414 are composed of the same frequency f B and local oscillation signals LOB1 to LOBN of different phases are driven separately. Furthermore...

Embodiment approach C

[0048] Figure 10 The frequency response of the feedforward filter in Embodiment C of the present invention is illustrated. This implementation is similar to Figure 8 The difference between embodiment B and embodiment B is that the outputs of the first path and the second path are combined by using a signal adder instead of a signal subtractor. Therefore, a different equivalent frequency response H can be obtained 430 ’, this frequency response has multiple passbands. If more paths driven by oscillating signals of different frequencies are added to the feedforward filter, more passbands can be created in the frequency response.

[0049] The feedforward filters in embodiments B and C can be used in multi-channel communication systems to receive multiple desired channels at different frequencies and reject all other undesired channels, harmonics, interference and noise. For example, in a TV system, if it is desired to display programs on multiple channels, this filter can b...

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

Described in embodiments herein are techniques for realizing filters having a variety of frequency responses, such as multiple pass-bands, high out-of-band rejection, without complicated designs. In accordance with an embodiment, a feedforward filter includes a first path, at least one second path and a signal combiner. The first path has a first translational filter, and employed for providing a first frequency response and generating a first output in response to an input signal based on the first frequency response. The at least one second path has a second translational filter and is coupled to the first path. The at least one second path is employed for providing a second frequency response that is different from the first frequency response to the input signal, and generating at least one second output in response to the input signal based on the second frequency response. The signal combiner is coupled to the first path and the second path, and employed for combining the first output and the at least one second output to generate a filtered signal.

Description

[0001] Cross References to Related Applications [0002] This application claims priority to US Provisional Application No. 61 / 952,571, filed March 13, 2014, the entire contents of which are incorporated herein by reference. technical field [0003] The present invention relates to filters, more particularly to feedforward filters having multiple paths connected in parallel, where each path is based on a translational filter. Background technique [0004] Filters are capable of passing desired signals in a frequency range to subsequent stages while rejecting other undesired signals or interference. Some characteristics of filters such as high quality factor, high linearity, high out-of-band rejection and low in-band loss are highly desirable. However, these features are difficult to implement in low-cost, low-power, and small filters with conventional architectures. Therefore, it is necessary to provide a novel architecture to realize filters with good performance based o...

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): H03H19/00H04L27/148
CPCH03H19/002H03D7/165H04L25/0278
Inventor 吕盈苍洪志铭李孟璋
Owner MEDIATEK INC
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Patsnap Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Patsnap Eureka Blog
Learn More
PatSnap group products

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

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com