HighBeam Research - Newspaper archives and journal articles
Options
Cancel changes
Follow us:
  • Subscription benefits
  • Log in
  • Sign up for a free, 7-day trial
  • Publications
  • Research topics
  • Topics home
  • People
    • Artists and Entertainers
    • Company executives
    • Historical figures
    • Politicians and Government officials
    • World Leaders
  • Issues and Events
    • Health and Medicine
    • Historical Events
    • Religion and Theology
    • Science and Technology
  • Places
  • Organizations
  • A-Z
    • A-G
    • H-O
    • P-T
    • U-Z
    • 0-9
  • Publications home
  • Journals
    • Academic journals
    • Business journals
    • Education journals
    • Math and Engineering journals
    • Medical journals
    • Science and Technology journals
    • Trade journals
  • Magazines
    • Business magazines
    • Computer magazines
    • Education magazines
    • Industry magazines
    • Lifestyle magazines
    • Medical magazines
  • Newspapers
    • International newspapers and newswires
    • Reports, newsletters, and transcripts
    • U.K. newspapers
    • U.S. newspapers and newswires
  • Reference works and books
    • Almanacs
    • Dictionaries and thesauruses
    • Encyclopedias
    • Non-fiction books
  • Subscription benefits
  • Log in
  • PUBLICATIONS HOME
  • Journals
    • Academic journals
    • Business journals
    • Education journals
    • Math and Engineering journals
    • Medical journals
    • Science and Technology journals
    • Trade journals
  • Magazines
    • Business magazines
    • Computer magazines
    • Education magazines
    • Industry magazines
    • Lifestyle magazines
    • Medical magazines
  • Newspapers
    • International newspapers and newswires
    • Reports, newsletters, and transcripts
    • U.K. newspapers
    • U.S. newspapers and newswires
  • Reference works and books
    • Almanacs
    • Dictionaries and thesauruses
    • Encyclopedias
    • Non-fiction books
Home » Publications » Math and Engineering journals » EE-Evaluation Engineering » March 2006 »
  • Save
    This article has been saved!
    You may organize and add notes about this article below.
    This article has been saved!
    View all saved articles
  • Export

    To export this article to Microsoft Word, please log in or subscribe.

    Have an account? Please log in

    Not a subscriber? Sign up today

  • Print
  • Cite

    MLA

    Lecklider, Tom. "Seizing power accurately: a single-parameter modulated RF power measurement is just so 20th century.(RF POWER METERS)(Cover story)." EE-Evaluation Engineering. NP Communications, LLC. 2006. HighBeam Research. 25 Apr. 2018 <https://www.highbeam.com>.

    Chicago

    Lecklider, Tom. "Seizing power accurately: a single-parameter modulated RF power measurement is just so 20th century.(RF POWER METERS)(Cover story)." EE-Evaluation Engineering. 2006. HighBeam Research. (April 25, 2018). https://www.highbeam.com/doc/1G1-143569349.html

    APA

    Lecklider, Tom. "Seizing power accurately: a single-parameter modulated RF power measurement is just so 20th century.(RF POWER METERS)(Cover story)." EE-Evaluation Engineering. NP Communications, LLC. 2006. Retrieved April 25, 2018 from HighBeam Research: https://www.highbeam.com/doc/1G1-143569349.html

    Please use HighBeam citations as a starting point only. Not all required citation information is available for every article, and citation requirements change over time.

Seizing power accurately: a single-parameter modulated RF power measurement is just so 20th century.(RF POWER METERS)(Cover story)

EE-Evaluation Engineering
EE-Evaluation Engineering

See all results for this publication

Browse back issues of this publication by date

March 1, 2006 | Lecklider, Tom | Copyright
COPYRIGHT 2009 Nelson Publishing. This material is published under license from the publisher through the Gale Group, Farmington Hills, Michigan. All inquiries regarding rights or concerns about this content should be directed to Customer Service.
  • Permalink

    Create a link to this page

    Copy and paste this link tag into your Web page or blog:

    <a href="https://www.highbeam.com/doc/1G1-143569349.html" title="Seizing power accurately: a single-parameter modulated RF power measurement is just so 20th century.(RF POWER METERS)(Cover story) | HighBeam Research">Seizing power accurately: a single-parameter modulated RF power measurement is just so 20th century.(RF POWER METERS)(Cover story)</a>

The first step in making accurate RF power measurements is choosing the sensor most appropriate for the signal. Obviously, you wouldn't use a sensor limited to 1 mW (0 dBm) for a 1-W (30-dBm) signal. Nor can you use a thermal sensor to measure the peak power of a fast pulse. And, a simple diode sensor calibrated to read the correct power level of CW signals can't be used for digitally modulated signals above about -20 dBm.

In addition, RF power measurement is subject to several sources of uncertainty. These include instrumentation accuracy, noise, zero set and drift, reference power uncertainty, reference-to-sensor mismatch, sensor linearity, sensor calibration factor uncertainty, sensor-to-signal mismatch uncertainty, and temperature effects. Of these, the two mismatch components often dominate.

If the signal to be measured is relatively large, you can minimize the mismatch uncertainty by placing a precision attenuator in the measurement path. Power reflected because of the impedance mismatch will be reduced by the attenuator on its way back to the signal source. If the attenuator characteristics are very stable and well known, inserting the attenuator should reduce the measurement uncertainty even though another element has been introduced into the circuit.

Many of the other measurement uncertainties relate to the power meter with which the sensor is used. Zero set and drift have been improved by design so that both effects are small in new meters. And, at very low levels, many power meters reduce their bandwidth and use averaging to enhance the signal-to-noise ratio. At higher signal levels, noise generally is not a problem. Sensor linearity remains as the next largest error source.

Sensors

Thermistors, diodes, and thermopiles are the more popular types of terminating RF sensors. Thermistors and thermopiles, as their names suggest, measure the amount of heat created by the RF signal. As such, these devices are not limited by video bandwidth or type of modulation. They accurately measure average RF power. Unfortunately, thermistors have only a limited dynamic range. New, integrated thermopiles are very linear but too slow in responding to a signal change to measure peak power, for example.

Diode-based sensors now have video bandwidths in excess of 35 MHz and, separately, a 90-dB dynamic range. However, there are many types of diode-based sensors, and they are not all created equal.

Basic Diode Sensor

A Schottky metal-semiconductor diode naturally exhibits a square-law characteristic for low signal levels up to about -20 dBm. This means that the current through the diode is directly proportional to the square of the voltage across it. Sensors using two diodes in a full-wave rectifying arrangement, as shown in Figure 1, develop twice the output signal of a single diode circuit.

For low-level signals, this sensor circuit works well, generally requiring averaging and a chopper-stabilized amplifier to detect the very small signals corresponding to -70-dBm power levels. Nevertheless, the output is linear with power so accurate measurements result for any type of modulation if the peak power level remains below -20 dBm.

[FIGURE 1 OMITTED]

Bird Electronic, a producer of in-line-type RF wattmeters used in the broadcast industry, has developed the diode-based BPM Series Broadcast Power Monitors. …


To read the full text of this article and others like it, subscribe today!



Related articles on HighBeam Research

US Fed News Service, Including US State News
Wipo Publishes Patent of the Johns Hopkins University, Paul A. Bottomley, William Edelstein, Abdel-Monem M. El-Sharkawy, Di Qian for "High Dynamic...

US Fed News Service, Including US State News; October 3, 2012

427 words
GENEVA, Oct. 3 -- Publication No. WO/2012/129430 was published on Sept. 27. Title of the invention: "HIGH DYNAMIC RANGE RF POWER MONITOR." Applicants: THE JOHNS HOPKINS UNIVERSITY (US), BOTTOMLEY Paul A. (US), EDELSTEIN William (US), EL-SHARKAWY Abdel-Monem M. (US) and QIAN Di (US). Inventors: Paul…
US Fed News Service, Including US State News
US Patent Issued to Massachusetts Institute of Technology on Feb. 24 for "Method and Apparatus for High Efficiency, High Dynamic Range Digital RF...

US Fed News Service, Including US State News; February 24, 2015

425 words
ALEXANDRIA, Va., Feb. 24 -- United States Patent no. 8,964,881, issued on Feb. 24, was assigned to Massachusetts Institute of Technology (Cambridge, MassMethod and apparatus for high efficiency, high dynamic range digital RF power amplification" was invented by Sushmit Goswami (Cambridge,…
US Fed News Service, Including US State News
Wipo Publishes Patent of Massachusetts Institute of Technology and Sushmit Goswami for "Method and Apparatus for High Efficiency, High Dynamic...

US Fed News Service, Including US State News; February 21, 2014

398 words
GENEVA, Feb. 21 -- Publication No. WO/2014/028036 was published on Feb. 20.Title of the invention: "METHOD AND APPARATUS FOR HIGH EFFICIENCY, HIGH DYNAMIC RANGE DIGITAL RF POWER AMPLIFICATION."Applicants: MASSACHUSETTS INSTITUTE OF TECHNOLOGY (US) and Sushmit Goswami (IN).Inventors: Sushmit Goswami…
Product News Network
RMS Detector features 57 dB dynamic range.(40MHz to 10GHz RMS Detector with 57dB Dynamic Range Provides Accurate RF Power Measurement)

Product News Network; June 18, 2010

700+ words
Powered from single 3.3 V supply with operating current of 42 mA, 10 GHz Model LTC5582 measures RF signals with [+ or -]0.2 dB linearity over 43 dB dynamic range at 2.14 GHz, regardless of high crest-factor modulations used in 3G and 4G broadband wireless networks. Log-linear response converts RF…
Microwave Journal
Temperature Compensated RF Power Detectors. (New Products: Components).

Microwave Journal; February 1, 2002

301 words
The model LTC5505-1 and LTC5505-2 RF power detectors offer > 40 dB dynamic range for 300 MHz to 3 GHz applications. Each requires 60 percent of the PCB space needed by a discrete design, consumes nine times less supply current and, compared to integrated solutions, minimizes system design iteration…
See all related articles »

Publication Finder

Browse back issues from our extensive library of more than 6,500 trusted publications.

Popular publicationson HighBeam Research

The Washington Post
Washington D.C. newspapers
Chicago Sun-Times
Illinois newspapers
The Christian Science Monitor
Religious magazines
The Economist (US)
Political magazines
The Mirror (London, England)
U.K. newspapers
Visit Cengage Brain
  • Company
  • About us
  • Subscription benefits
  • Group subscriptions
  • Careers
  • Privacy policy
  • Terms and conditions
  • Contact us
  • Help topics
  • FAQ
  • Search tips
  • Using the Research Center
  • Billing questions
  • Rights inquiries
  • Customer Service
  • Cengage Learning Network
  • Questia
  • CengageBrain.com
  • HighBeam Business
  • ed2go
  • MiLadyPro
  •  
HighBeam Research
Follow us:

HighBeam Research is operated by Cengage Learning. © Copyright 2018. All rights reserved.

The HighBeam advertising network includes: womensforum.com GlamFamily