Cabe Atwell
User Rank
Re: filter symetery
Cabe Atwell   1/20/2014 5:42:14 PM
These RF posts never cease to amaze me. 

User Rank
filter symetery
Leer   12/18/2013 7:16:21 PM
Filters are a complex topic. I have designed them for over 20 years. The topic of symetery is interesting in that most are symeterical if looked at with the frequency scale in log format and if a "full bandwidth" approximation is used.The best I can suggest is to provide some references you can use to gain a better understanding of filters. "Handbook of Filter Synthesis" by Anatol I. Zverev 1967 This is great for the tables but does not provide the necessary ne-normilization equations. "Filtering in the Time and Frequency Domains" by Herman J. Blinchikoff 1976. This is an advanced text that will require some study. "The Analysis, Design, and Synthesis of Electrical Filters" by DeVerl S. Humpherys 1970. This is a graduate course in filter synthsis. "Electronic Filter Design Handbook" by Arthur B. Williams. This is an entry level book but is filled with errors so you almost need to know the material before using it. But it can provide some useful information. and last "comprehensive Filter Design" by Lee R Watkins 1997. This has a lot of useful information and most all of the de-normaiization equations as well as a host of graphs to assist in the design of filters. Good Luck!

William K.
User Rank
Yes, the passband is non-symetrical
William K.   12/4/2013 9:21:06 PM
Thanks for the education! I have observed for many years that filter pass-bands are not symetrical, but I had not had an adequate explanation until this one. So thanks for not only explaining the cause, but also describing a solution. Of course, after those series sections are added the design is not really a simple filter any more. BUT having a good explanation is certainly worthwhile. Thanks for the educational post!

User Rank
keep the RF stories coming
cpu   12/4/2013 6:17:00 PM
I enjoy these RF stories. Keep them coming.

Partner Zone
Latest Analysis
Governmental policies and mandates in Europe are leading the way in creating low-carbon manufacturing.
Digital healthcare devices and wearable electronic products need to be thoroughly tested, lest they live short, ignominious lives, an expert will tell attendees at UBM’s upcoming Designers of Things conference in San Jose, Calif.
Designers of electronic interfaces will need to be prepared to incorporate haptics in next generation products, an expert will tell attendees at the upcoming Designers of Things conference in San Jose, Calif.
According to a Randstad Engineering compilation of salary studies, engineering salaries are increasing beyond inflation, with employers paying to keep potential suitors away from their employees.
The company says it anticipates high-definition video for home security and other uses will be the next mature technology integrated into the IoT domain, hence the introduction of its MatrixCam devkit.
Design News Webinar Series
11/10/2015 11:00 a.m. California / 2:00 p.m. New York
10/29/2015 11:00 a.m. California / 2:00 p.m. New York
10/20/2015 8:00 a.m. California / 11:00 a.m. New York
12/2/2015 11:00 a.m. California / 2:00 p.m. New York
Quick Poll
The Continuing Education Center offers engineers an entirely new way to get the education they need to formulate next-generation solutions.
Jul 6 - 10, Building Raspberry Pi Controllers with Python
SEMESTERS: 1  |  2  |  3  |  4  |  5  |  6 |  7

Focus on Fundamentals consists of 45-minute on-line classes that cover a host of technologies. You learn without leaving the comfort of your desk. All classes are taught by subject-matter experts and all are archived. So if you can't attend live, attend at your convenience.
Learn More   |   Login   |   Archived Classes
Twitter Feed
Design News Twitter Feed
Like Us on Facebook

Sponsored Content

Technology Marketplace

Copyright © 2015 UBM Canon, A UBM company, All rights reserved. Privacy Policy | Terms of Service