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Newsletter "Packets" - Wireless News and Regulatory Updates

Issue 8

News for EMC engineers

Providing information and fielding questions for wireless manufacturers are some of the many activities that we perform at ACB. Packets provides an overview of just a small portion of the communiqués that run in and out of our office.

Does the FCC require peak power or maximum RMS for Parts...

Many vehicles controlled by Programmable Logic Control (PLC) systems...

We have a 3-Phase 480V 50A contactor and motor causing interference...

What is the effect of EMI (Electromagnetic Interference) caused by...

We have a receiver that operates at 49 MHz and 433.92 MHz that includes...

Designating Accrediting Authority Daily Updates; DFS FCC, IC, ETSI Standards

 

Questions and Answers:

Q:  Does the FCC require peak power or maximum RMS for Parts 27 and/or 90?

A:  Devices operating under 27 or 90Y require peak power test, in accordance with 47 CFR 27.50(i) or 90.1215(c), respectively.

 

Q: Many vehicles controlled by Programmable Logic Control (PLC) systems seem to fail when operating close to a railway lines (1500V DC 16kHz).  What is the most effective way to investigate this problem?

A: This appears to be interference from potential coupling from the DC-rectified high voltage train power.  First, it is necessary to quantify the noise -- perform a survey of the electromagnetic fields around the PLC and where the communication and power wiring runs and connects to the PLC inside the vehicle.  This will give you an idea of the energy that is present.  The 1500 VDC 16 kHz railway source with many harmonics in the tens of Megahertz may be affecting the PLC system.  The measurements must be performed as radiated and conducted in order to get a good idea of the electromagnetic environment.  Then, a susceptibility test can be performed such as IEC 1000-4-6, simulating the levels found during the survey.  The probable causes of such problems are poor shields on the I/O and communication lines on vehicles.  Improving the grounds to the shields and using filters on the most sensitive lines should be helpful in mitigating the problem. back to top...

 

Q: We have a 3-Phase 480V 50A contactor and motor causing interference to a C-band satellite receiver in the 3700-4200 MHz range.  What are some options to prevent this problem?

A: If the motor is being driven by a solid-state drive, then the interference may be from harmonics of the switching activity of the solid-state drive.  The C-Band satellite operates at quite a high frequency to interfere with, so it may be commutator (arcing) noise, which may have a broad frequency range.  If you can use a Spectrum Analyzer and antenna or antenna probe ("snuffer") to validate the frequency of interference, install filters on the wiring.  These filters would have to be very small value and physical size to work in the 4 GHz range.  Another option is shielding the power harness.  The shield needs to be fully along the length of the harness and terminated (bonded) to the case of the equipment at each end.  A ground wire will not work; it needs to be a fully terminated shield construction. back to top...

 

Q:  What is the effect of EMI (Electromagnetic Interference) caused by inductor/capacitance components, which are used as part of charge pumps associated with a main chip?  The inductor and capacitance are just single individual components.  The operating frequency is about 1 MHz or possibly more, and the inductance and capacitance are 0.1uH and 0.1 uF each with VCC=1.2 V, as an example.  The output current might be around 10~20 mA, in other words, the 10~20 mA is transferred through 0.1 uH inductor with 1 MHz or more.  We are concerned that the magnetic field might affect other sensitive devices like RF circuitry.

A:  The strength of the magnetic field from a current-carrying conductor depends on the current, the size of the loop area of the current and the distance from the conductor. If the component is close to a magnetically susceptible component, then there is a chance for interference.  The 10 mA is not a particularly high level of current, but if the device is located near a susceptible circuit then there could be a problem.  The best way to minimize this is to keep all traces carrying the current to a minimum size, short, direct and use a ground plane on the PCB.  An excellent technical article on decoupling is located at http://download.micron.com/pdf/technotes/TN0006.pdf.
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Q: We have a receiver that operates at 49 MHz and 433.92 MHz that includes a motor.  However, our understanding is that a regular motor is exempted from FCC Part 15 testing.  Therefore, should disturbance from the motor in our receiver be considered under FCC Part 15.109?

A: The FCC does not consider disturbances from motors as long as the motor is a regular AC or DC motor with AC source frequency less than 9 kHz.  Furthermore, interference from Pulse Width Modulator (PWM) motors is considered under FCC Part 15.109. back to top...

 


American Certification Body

Designating Accrediting Authority Daily Updates; Federal Communications Commission (FCC), Industry Canada (IC), and Compliance Europe (CE)

 

FCC: TCB Exhibit Upload Procedure Change Notification

As of June 27, 2006, the five day grace period for upload of required exhibits to the FCC site for TCB approved applications has been discontinued. All Exhibits are required to be uploaded to the FCC site prior to completion of any Grant.

In addition, if any corrections or revisions are required by the Applicant for any exhibits once uploaded to the FCC website and after the Grant of Equipment Authorization has been issued, resulting in any corrective action or Dismissal, a new Application Form 731 plus an additional handling charge of 50% will be required in advance before any processing begins. back to top...

 

Dynamic Frequency Selection - The FCC released a public notice requesting further comment on the new Dynamic Frequency Selection (DFS) requirements which are scheduled for implementation in July.  All devices operating in the 5G frequency range will be required to undergo a stringent testing regimen to obtain FCC approval for marketing in the United States.  See public notice http://hraunfoss.fcc.gov/edocs_public/attachmatch/DA-06-927A1.pdf  for further details.

The FCC has released the Memorandum Opinion and Order June 30, 2006; Revision of Parts 2 and 15 of the Commission's Rules to Permit Unlicensed National Information Infrastructure (U-NII) devices in the 5 GHz band.
ET Docket No. 03-122.
 
Applications for equipment certification of U-NII devices filed on or after July 20, 2006 must comply with the U-NII rules for TPC and DFS. All U-NII devices operating in these bands that are imported or marketed on or after July 20, 2007 also must comply with the TPC and DFS requirements. news

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IC

Broadband Spectrum Cap Policy - The Department of Industry has decided to rescind the existing broadband spectrum cap policy applicable to certain spectrum in the 24, 28 and 38 GHz bands.  Their decision factors in the submissions received in the public consultation process initiated by the spectrum policy review of the 3-30 GHz range announced in Canada Gazette, notice DGTP-008-04 as well as the policy objectives of the Telecommunications Act.

Notice No:  SMSE – 004-06 - announces the release of Issue 5 of Standard Radio System Plan 307.1 – Technical Requirements for Fixed Line of Sight Radio Systems Operating in the Band 7125-7725 MHz. This standard replaces Issue 4 and states the minimum technical requirements for the use of the band by low, medium and high capacity digital point - to - point radio systems in the fixed service.

Notice No. SMSE 006-06 - announces the release of Issue 4; Interference-Causing Equipment Standard - 001 (ICES-001): Industrial, Scientific and Medical (ISM) Radio Frequency Radiators.  Issue 4 sets out mandatory requirements for limits and methods of measurement of radio frequency noise emissions from ISM equipment.

Notice No. DGTP 005-06 - announce the release of the Spectrum Utilization Policy, Technical and Licensing Requirements for Broadband Pubic Safety in the Band 4940-4990 MHz. SP 4940 MHz addresses the principal issues governing the implementation of public safety services in the band 4940-4990 MHz, including eligibility, licensing, technical and service rules.

Test Reports - The issue of test report expiration was discussed at a recent TCBC workshop.  A test report must not be more than one year old.  To utilize a test report that exceeds this time limit, a laboratory may revalidate the report to current requirements.  IC has mentioned that this should be addressed in more detail in the next revision to RSS-GEN expected later this year. back to top...

 

CE

ETSI Standards Published

ETSI EN 302 288-2 V1.2.1 (2006-05)  Short Range Devices; Road Transport and Traffic Telematics (RTTT); Short range radar equipment operating in the 24 GHz range; Part 2: Harmonized EN under article 3.2 of the R&TTE Directive.

ETSI Standards on Public Enquiry

ETSI EN 302 435-2 V1.1.1 (2006-05)  Short Range Devices (SRD); Technical characteristics for SRD equipment using Ultra Wide Band technology (UWB); Building Material Analysis and Classification equipment applications operating in the frequency band from 2.2 GHz to 8 GHz; Part 2: Harmonized EN covering essential requirements of article 3.2 of the R&TTE Directive.

ETSI EN 302 510-2 V1.1.1 (2006-05)  Radio equipment in the frequency range 30 MHz to 37.5 MHz for Ultra Low Power Active Medical Membrane Implants and Accessories; Part 2: Harmonized EN covering essential requirements of article 3.2 of the R&TTE Directive.

ETSI EN 301 908-1 V3.2.1 (2006-06)  Base Stations (BS), Repeaters and User Equipment (UE) for IMT-2000 Third-Generation cellular networks; Part 1: Harmonized EN for IMT-2000, introduction and common requirements, covering essential requirements of article 3.2 of the R&TTE Directive.

ETSI EN 301 908-2 V3.2.1 (2006-06)  Part 2: Harmonized EN for IMT-2000, CDMA Direct Spread (UTRA FDD) (UE) covering essential requirements of article 3.2 of the R&TTE Directive.

ETSI EN 301 908-3 V3.2.1 (2006-06)  Part 3: Harmonized EN for IMT-2000, CDMA Direct Spread (UTRA FDD) (BS) covering essential requirements of article 3.2 of the R&TTE Directive.

ETSI EN 301 908-7 V3.0.0 (2006-06)  Part 7: Harmonized EN for IMT-2000, CDMA TDD (UTRA TDD) (BS) covering essential requirements of article 3.2 of the R&TTE Directive.

ETSI EN 301 908-11 V3.2.1 (2006-06)  Part 11: Harmonized EN for IMT-2000, CDMA Direct Spread (UTRA FDD) (Repeaters) covering essential requirements of article 3.2 of the R&TTE Directive.

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Please note that the above represents, in most cases, technical opinions with justification in regulatory agency requirements, the particulars of the product must be considered. Thus, we welcome a call or email if you have any special needs or questions.

 

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