Washington Laboratories (301) 417-0220 web: Lindbergh Dr. Gaithersburg, MD 20879 Cellphones and...
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Transcript of Washington Laboratories (301) 417-0220 web: Lindbergh Dr. Gaithersburg, MD 20879 Cellphones and...
Cellphones and Licensed Radio Reports
What is a Licensed Transmitter?
Licensed transmitters are devices which have been granted specific sections of the radio frequency spectrum for their use.
Equipment authorized for these services theoretically must also go through the Wireless Bureau before being placed in service
Is a Licensed transmitter an “Intentional Radiator”?
An “Intentional Radiator” is a legal term used exclusively for Unlicensed Part 15 radio transmitters. Do not confuse the usage of the term within the Rules.
Test Report Construction Notes
All Licensed devices use portions of TIA/EIA 603 as a basis for some testing and report construction.
It is not recommended that any laboratory begin Licensed radio testing without a full understanding of Part 15B and 15C report building.
Building a Test Report
Licensed radio test reports use a completely different technique for referencing the applicable FCC rules then Part 15.
Extensive use of Part 2 is required.o Part 2 is the oldest section of the
Rules
Additional service-specific rules (Part 22/24 or Part 90) require additional tests and documentation
Required Exhibits
AmericanTCB has it’s own easy-to-use application form in MS Word format for use in all filings. A completed Application is required before any work can proceed.
In addition to the Test Report a number of specific Exhibits are required.
Exhibits which accompany all filings
o Labelo Internal Photographso External Photographso Cover Letterso Operational Description*o Schematics*o Block Diagrams*o Manualo Test Setup Photographs
o * Can be held “Confidential”
Additional Exhibits
o Parts List*o Tune-Up Procedures*o SAR Report (if required)
Test Setup Photos can legally be omitted, but this is not recommended
RF Exposure
RF Exposure is a complex area and is relatively one of the newest sections of the Rules. Requirements are still changing and may need additional care before testing or filingo Check and consult with ATCB to
determine if any recent regulatory changes
Finding FCC Regulations
The Government Printing Office now provides on-line FCC Rules.
These are the most recent available and usually are the best for updates
http://ecfr.gpoaccess.gov/cgi/t/text/text-idx?c=ecfr&tpl=%2Findex.tpl
Part 2
Part 2 is the oldest section of the Rules.
It dates back to a “pre-standards” era with FCC equipment authorization procedures
It has withstood the challenge of time and is still very valid to this day
2.201 – Emission Designators
Emission designators are required for all Licensed radio services.
They inform the Wireless Bureau in a shorthand manner of the kinds of emissions to be expected from a specific radio transmitter.
Examples:o 1M25F9W CDMAo 11K5F3E Narrowband analog voiceo 300KGXW GSM
2.1046 – RF Power Output
Licensed devices where the antenna is not supplied by mfg – peak conducted power
Licensed devices where the antenna is non-detachable – peak radiated powero For Part 22 – ERPo For Part 24 - EIRP
Radiated power measurements
Substitution measurements as described in TIA/EIA 603 are required.
For UHF frequencies and above consider the effects of impedance mismatch and cable shield radiation.o Use ferrites on substitution cableo Measure SWRo Determine the “real” power loading on the
substitution antennao Accuracies to .3dB have been demonstrated.
2.1047 – Modulation Characteristics
This section requires testing for analog systems which change emission envelope relative to the frequency and amplitude of the intelligence.o See TIA/EIA 603
Digital systems which employ a “constant envelope” fundamental can simply provide a description of the modulating intelligence.
2.1049 – Occupied Bandwidth
A spectral plot of the emission at highest and lowest powers.
A low/high power plot for each emission type for each is required.
For multiple data rates usually “worst case” will suffice.
Analog systems should reference TIA/EIA 603 for procedure
2.1051 / 2.1053 – Spurious Emissions
This is two tests:o Conducted spurs from the antenna porto Radiated emissions from the cabinet using
a terminated transmitter
However, for devices with integral or non-detachable antennas a radiated test only is sufficient using the antenna supplied by manufacturer
Substitution method is required.
2.1055 Frequency Stability
Frequency variation over temperature o Usually -30C to +50C.
Frequency variation over voltage o Usually +/- 15% of Standard Test
Voltageo If battery operated, an additional test
at the Battery End Point is recommended
Additional Rule Specific Tests
Specific tests are required for all Licensed rule parts.
For Cellphones, the additional rules found in Part 22/24 apply.
For IDEN additional rules are found in Part 90
Marine radios – Part 80FRS – Part 95
o Consult with ATCB for additional applicable rule sections.
Part 22/24
Cellphones require additional emissions testing at the band edge.
Easiest to perform using conducted measurements, but radiated methods can be used.
Fairly explicit instructions can be found in either 22.359(b) or 24.238(b). o For questions contact ATCB
2.1033(c)(8)
FCC rules require noting the voltage and current through the final radio frequency amplification device be listed in the Test Report.
This does not have to be a hard test. If needed ATCB will provide you with a simple method for obtaining these values.
15.19(a)(1) Labeling
End users of receivers used with Licensed radio services have specific rights not given to other Part 15 operations. Their labeling in addition to the FCC ID should read:o This device complies with part 15 of the
FCC Rules. Operation is subject to the condition that this device does not cause harmful interference.