Issue 20/March 2011

ACB news for engineers

Newsletter "Packets" - Wireless News and Regulatory Updates
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. 

New Offering!
Making RF Power Measurements on Wireless Devices by Dennis Ward

March 24 (12:00-1:00 p.m. EST)

Learn: How to make complex power measurements for regulatory compliance

In this issue

  • In the News:
    ACB Gains ANSI Accreditation to Japan Radio Standards >>
    Chapter Meeting of the IEEE >>

  • You need to know!
    IC RF Exposure Annexes >>
    REVISION of RSS-123 >>

  • Q & A: 
    ATSC TV receiver
    KDB 704992
    Modular Approval


  • Latest FCC KDB Publications: >>

  • New Official Journal of EMC Directive >>

in the news


ACB Gains ANSI Accreditation to Japan Radio Standards

Under the joint US-Japan Mutual Recognition Arrangement, the creation of Certification Bodies will allow US entities to certify devices for the Japan market. ACB is the first Body accredited to the Japanese MIC standards by the American National Standards Institute.

"This accreditation is a major step towards providing improved access to the Japanese market by telecommunications manufacturers in the US and our overseas clients.", Mike Violette, Director of ACB said. "This milestone is a major achievement for ACB and shows how public-private cooperation can support US industry. NIST, the FCC and our friends in Japan were keen to make this occur."

The next step in the process is recognition by MIC, which should be achieved by the time the cherry blossoms bloom in Washington, DC.


Chapter Meeting of the IEEE

American Certification Body will be exhibiting at the upcoming EMC Chapter Meeting of the IEEE Milwaukee Section.

Featured Event: Printed Circuit Board Layout for EMC Suppression with Dr. Todd Hubing of Clemson University. More Information

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you need to know


IC RF Exposure Annexes

The following is a basic concept of the requirements for IC RF Exposure Annexes.

1. IC always, under all conditions, expects either Annex A and B, or Annex C to be provided for any transmitter or transceiver.

2. The use of annex C is only applicable if the transmitter meets the exemption requirements stated in RSS102 section 2.5 as follows:

a. All transmitters are exempt from routine SAR and RF exposure evaluations provided that output power complies with the power levels of sections 2.5.1 or 2.5.2. If the equipment under test (EUT) meets the requirements of sections 2.5.1 or 2.5.2, applicants are only required to submit a properly signed declaration of compliance (see Annex C). The information contained in the RF exposure technical brief may be limited to information that demonstrates how the output power of the transmitter was derived.

b. If the EUT does not meet the appropriate exemption limit, a complete SAR or RF exposure evaluation shall be performed.

c. It must be emphasized that the above exemption from routine evaluation is not an exemption from compliance.

3. It is to be noted in 2 above, that in all cases, even those where exemption from RF exposure evaluation is provided, that an RF exposure technical brief is STILL required, but it only need show how the output power was derived for comparison to the limit in section 2.5 of RSS102.

4. All transmitters not meeting the power limitations of Section 2.5 (i.e. 2.5.1 for portable devices in which SAR is involved, and 2.5.2 for mobile RF exposure in which MPE is involved.

5. The individual scenarios are as follows:

a. Portable devices in which power exceeds the exemption limit of section 2.5.1: RSS102 annex A and B and SAR report.

b. Portable devices in which power does not exceed the exemption limit of section 2.5.1: RSS102 annex C and report only stating how power was derived in comparison to the limits.

c. Mobile devices in which power exceeds the exemption limit of section 2.5.2: RSS102 annex A and B and MPE report (caution as it may need MPE measured not only calculated even though most would only calculate MPE).

d. Mobile devices in which power does not exceed the exemption limit of section 2.5.2: RSS102 annex C and report only stating how the power was derived in comparison to the limits.

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Industry Canada will publish the following revised standard on February 26th, 2011:

Radio Standards Specification 123 (RSS-123), Issue 2: Licensed Low-Power Radio Apparatus. This document sets out the requirements for certification of licensed low power radio apparatus operating in various frequency bands, such as low-power auxiliary equipment and wireless cameras.

Important information 

This standard will come into force as of February 26th, 2011. Applicants for equipment certification including Certification Bodies for the certification of radio apparatus must ensure compliance with the new issue of this standard. 

Certification Bodies for the certification of radio apparatus have one year from the date of publication to amend their recognized scope of accreditation to reflect the new issue of this standard in accordance with Industry Canada procedures for conformity assessment bodies.

Copy of this standard is available electronically on the Spectrum Management and Telecommunications Web site at under official publications.    

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questions and answers



Can a ATSC TV receiver without NTSC function be manufactured, marketed and/or imported into the United States under FCC requirements?

No. A TV receiver must contain both a ATSC and NTSC tuner. NTSC requirements of sections 15.117, 15.118, 15.119, and 15.120 remain in effect as defined in sections 15.117(a), 15.118(a), 15.119(a), and 15.120(b). For example, section 15.117 applies to all TV broadcast receivers shipped in interstate commerce or imported in to the United States for sale or resale to the public.

Low power TV stations in the U.S. are permitted to continue broadcasting analog signals after June 2009. Many cable TV systems will also continue to carry analog TV signals.

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The device is a microwave oven which is the part 18 device. The MP-5 was issued in 1986. So whether or not the test site can use RF absorbing materials to cover a minimum area of the ground plane for the radiated emission test above 1 GHz?

KDB 704992 is for Part 15 equipment. However, we accept test reports and procedures for Part 18 devices.

We would accept ANSI C63.4-2009, clause 5.5 for the specific requirements for test facilities used to perform radiated emission measurements above 1 GHz. Only ANSI C63.4-2009, clause 5.5 addresses your question.

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I make modules and typically perform Full Modular Approval. I wish to sell a module without its own RF shield, which I believe is Limited Modular Approval. Is this ok to do? What are the differences in requirement for a Limited Modular Approval on a device with no shield?

Is it ok to test the module for Limited Modular Approval as a stand-alone device, as with a full modular approval?

What happens when an OEM installs my module into their host device?

Can a module approved to Limited Modular Approval be used in any host device?

It is important to remember that the Modular Approval process is designed to enable module installation into a range of hosts. To become a module approved for use in a wide range of host installations, the requirements of FCC Part 15.212 have been created. If any of these requirements are not met then it may be possible to gain Limited Modular Approval but of course then the use and installation of the module is also limited.

Limited Modular Approval is literally limited to a specific host or a group of similar hosts. Often the Limited Modular Approval is performed for installation into the Grantee’s own devices or into a specific range of devices manufactured by a known OEM.

Modules for Limited Modular Approval must be tested in a typical host device if no shield is installed. It could not be tested as a stand-alone device for Limited Modular Approval, if the module has no shield.

If the module manufacturer would like the module with Limited Modular Approval to be installed into a dissimilar host, then it must be tested in that host or range of hosts too.

If the module manufacturer intends the module with Limited Modular Approval to be installed into more than one range of hosts, then tests will need to be performed with the module in one of each type of host.

FCC Part 15.212(b) states that for a Limited Modular Approval, the applicant for certification must state how control of the end product into which the module will be installed will be maintained such that full compliance of the end product is always ensured.

This is an important point because it reminds the Grantee that they are always responsible for the ongoing compliance of their own module, therefore if they do not have a full modular approval, they must state how they control the installation. They must ensure it is only installed into the type of device it was tested and certified in.

The manufacturer of the module with Limited Modular Approval is responsible for compliance of the end product that hosts his module, not the OEM.

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1: What constitutes the bandwidth of a UWB emission?

2: How is the UWB emission bandwidth determined?

3: What portion of the UWB emission spectrum is required to be within the authorized frequency bands? Is it adequate for just the center frequency to be within the authorized band?

4: Can a device be certified under the UWB rules if its emission bandwidth resides outside of the authorized frequency bands when all of its emissions are below the prescribed limits?

5: What other subtleties should be considered when determining the bandwidth of a UWB device emission spectrum?

6: How are the emissions limits to be applied in determining compliance of a UWB device?

7: Is any specialized test equipment necessary for performing UWB compliance measurements?

8: What compliance information should be included with the application for certification?

9: What type of measurement antenna should be used for performing radiated emissions measurements on UWB devices when assessing compliance to the UWB rules?

10: Is there a provision for operating wireless tank level gauges under the UWB rules?

UWB Compliance Measurements Answers to FAQs :

1: The bandwidth of a UWB emission is defined by the points on the emission spectrum where the amplitude is 10 dB below the maximum emission amplitude (i.e., the -10 dB points). In cases where the measured emission spectrum contains multiple (more than two) -10 dB points, the outermost points define the bandwidth (i.e., the widest bandwidth is assumed).

2: The bandwidth of a UWB emission must be determined from a radiated measurement with the device using the antenna with which it is designed to operate (i.e., the antenna frequency characteristics may define the radiated bandwidth of a UWB device and is thus considered an integral part of the system). It is recommended that this measurement be performed using the spectrum analyzer peak detector with a resolution bandwidth of 1 MHz or greater and the maximum-hold function. The device under test should be measured for maximum bandwidth by varying the antenna height between 1 to 4 meters, varying antenna polarization between horizontal and vertical and rotating the device 360 several times.

3: For a UWB emission spectrum, the entire fundamental bandwidth (that portion of the spectrum between the outermost -10 dB points) must be contained within the authorized frequency band. For example, the emissions spectrum from a ground penetrating radar (GPR) applying for authorization under Section 15.509 must have its fundamental bandwidth located below 960 MHz.

4: It is presumed that this question refers to a scenario whereby the frequencies associated with the maximum emission and the -10 dB points are located within a frequency band that is outside of those bands authorized for UWB operation (e.g., 960-3100 MHz), but are less than the applicable emissions limit. Under these conditions, the requirement that the -10 dB bandwidth be fully contained within the authorized frequency bands is not realized and thus the device cannot be authorized.

5: When measuring the bandwidth of a UWB device using a radiated test set-up, it is imperative that appropriate adjustments be made to the measured amplitude levels to account for the frequency-dependent components of the measurement system (e.g., antenna gain or factor, pre-amplifier gain, cable loss, etc). Since UWB emissions can have bandwidths several GHz wide, these frequency-dependent characteristics can vary dramatically over the fundamental emission.

6: In each rule section pertaining to specific UWB applications, a table is included listing the emission limit applicable in each frequency band. The device under test must comply with all applicable limits accounting for all specified frequency bands. For example, an application for authorization of a device under Section 15.509 (low frequency imaging device) must demonstrate compliance not only to the emission limits provided for the 960-1610 MHz band, but also to those limits specified for both the 1610-1990 MHz and the above 1990 MHz band.

7: A spectrum analyzer with a quasi-peak detector is required for measuring UWB emissions below 960 MHz to verify compliance with the emissions limits in that portion of the spectrum. An analyzer with a true RMS detector is recommended, but not required, for measuring UWB emissions above 960 MHz. An alternative is provided in procedure (3) contained in Appendix F of the UWB First Report and Order (ET Docket No.98-153) for performing the emissions measurements with an analyzer that does not include an RMS detector. Also, a low-noise preamplifier is required to measure emissions to the levels necessary to determine compliance with the limits specified in the frequency band 960 to 1610 MHz for some UWB applications (e.g., indoor UWB devices authorized under Section 15.517). If the radiated measurements are not conducted in an anechoic chamber, then the use of this pre-amplifier may also require that a pre-select filter be inserted ahead of the pre-amplifier to prevent saturation from strong ambient RF signals.

8: At a minimum, the following information is required for processing a UWB application for certification: The UWB application category (e.g., imaging device, indoor system, handheld device, etc.) and the applicable rule section - The lower and upper -10 dB frequencies (fL and fH, respectively) and the frequency of the maximum observed emission level (fM) - A description of the procedure used to determine the UWB bandwidth - The maximum radiated emissions (including narrowband emissions) and the associated frequencies observed in each frequency band identified in the applicable emission limits tables - In the event that no emissions are observed in the above frequency bands, report the measurement systems minimum sensitivity (noise floor) in these bands (i.e., show that the measurement system was capable of detecting emissions down to the level dictated by the applicable emissions limit). - A complete description of the measurement system, including antenna, pre-amplifier, etc. This should include information such as antenna gain/factor, preamplifier noise figure and gain, particularly at each frequency for which a data point is provided (peak emission frequency, -10 dB points, etc.) - Calibration information for the measurement system at each frequency for which a data point is reported. - If applicable, report all digital circuitry emissions exceeding the applicable UWB limits and provide a complete description of the process used to justify invoking the exception stated in Section 15.521(c) - A description of the technique used to determine RMS average emission levels - A description of the test site used, specifying whether the measurements were performed in a test chamber, outdoor test site, with or without a ground screen, and any other pertinent information. – Where applicable, indicate the presence of required labels and/or a manual disable switch - Describe the pulse characteristics (PRF, pulse width, etc.). Is the pulse pseudo random (dithered) or periodic? An oscilloscope plot would be helpful. – Supporting photographs depicting the measurement system set-up and the device under test.

9: Two measurement antennas will likely be necessary for performing these tests. A log-periodic antenna is recommended for performing the necessary radiated measurements below 960 MHz, although other types of measurement antennas (e.g., biconical) can be used. For the radiated measurements above 960 MHz, a broadband horn antenna or a broadband log periodic antenna may be used. When using a horn antenna to measure emissions from a device that is not placed on a turntable (e.g., a ground penetrating radar placed near the ground to replicate actual operating conditions), the antenna should be pointed in the direction of the radiating head. This is consistent with ANSI C63.4 Section, which states that the antenna must be kept within the cone of radiation and pointed at the area of the device under test

10: Section 15.517(a)(4) authorizes the use of tank level gauges as indoor UWB devices only if they are used within metal or underground storage tanks, and the emissions are directed downward.

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latest KDB publications

arrow 388624 

What devices require FCC permission for a TCB to issue a grant of equipment authorization, and what are the procedures to obtain permission?
388624 D01 Permit But Ask Procedure v08 

388624 D02 Permit But Ask List v09r02 

arrow 178919 

What are the Federal Communications Commission (FCC) guidelines for permissive changes?
178919 D01 Permissive Change Policy v04r05 

arrow 273109 

What is the equipment authorization guidance for Part 25 Transceivers?
273109 D01 Equip Auth Guid Part 25 TXReceiver v02ro2 

arrow 594280 

Can a grantee permit users, professional installers or authorized service dealers to set the RF parameters or conditions of operations for an approved transmitter by setting country code, or other software configuration controls to ensure compliance; and is it sufficient to provide in the users manual a statement similar to: "WARNING: Select only the country in which you are using the device. Any other selection will make the operation of this device illegal."?

arrow 442812  

What are the guidelines for providing a software operational description with an application for certification as required by Section 2.944 for a Software Defined Radio?
442812 D01 SDR Apps Guide V01 

arrow 996369  

What is the FCC guidance for equipment authorization of transmitter module devices, and equipment that incorporates transmitter modules?
996369 D01 Module Certification Guide v01r01 

arrow 285076  

What are the equipment authorization requirements for hearing aid compatibility of mobile handsets?
285076 D01 HAC Guidance v02r01 

arrow 610077  

What are the post market surveillance requirements for a Telecommunications Certification Body (TCB)?
610077 D01 TCB Post Market Surveillance v05r01 

arrow 641163  

What guidance does the FCC provide to Telecommunication Certification Bodies (TCBs) regarding their roles and responsibilities as an obligation of being recognized by the FCC?
641163 D01 TCB Program Roles and Resp v01r01

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New Official Journal of EMC Directive

As of 24 February 2011, a new Official Journal of harmonised standards for compliance with the European EMC Directive has been published.
Official Journal of the European Union

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

American Certification Body, Inc.
6731 Whittier Avenue, Suite C110
McLean, VA 22101
Office: 703-847-4700