05-07-2012, 11:33 AM
Wireless Product Testing
Wireless Product Testing.ppt (Size: 2.55 MB / Downloads: 183)
Licensed Radio Services General Testing Requirements
FCC Part 2.1046 through 2.1057 Cover tests for all licensed devices.
The basics rationale of all FCC tests originate within this section. This is the oldest of the FCC rules
Built for the “narrowband world”, but still adaptable to broadband radio concepts
Licensed Radio Services Test Parameters
Remember that the purpose of performing the measurements required and submitting interpretations is to establish compliance with the technical requirement contained in the Radio Service Rules. These rules are “pre-standards”. In other words they evolved before there were generally accepted measurement standards and practices.
Basic Test Parameters
Power Output: 2.1046
Traditionally thought of as a “caloric” measurement. Use of common CW power meters were common. Great deal of measurement certainty.
Part 15 began the usage of “peak reading” power meters. Most unlicensed transmitter sections still require the concept of “peak power” unless specifically stated otherwise
Modulation Characteristics 2.1047
For analog radio transmissions (AM, FM, SSB) understanding basic parameters such as audio response and audio low pass filter were necessary to determine compliance. Testing usually required
For today’s “constant envelope” digital modulation systems this is basically unnecessary, but still must be described. Testing usually not required.
Occupied Bandwidth 2.1049
Occupied Bandwidth is defined as that portion of the spectrum where 99% of the emitted energy exists. The results are used to compare modulated spectrum with emissions masks.
Although not explicitly specified, all Certification reports including Part 15 must have an occupied bandwidth plot
Plot should be presented for each type of modulation
Antenna Terminal Spurious Emissions 2.1051
(Also known as Antenna Conducted Emissions)
View levels of conducted harmonics applied to the antenna.
An extension of the occupied bandwidth test. Show spurious emissions to 10th harmonic.
Unless specified elsewhere, RBW should be equal or greater than Tx emission bandwidth
Field Strength of Spurious Emissions 2.1053
Test includes emissions radiated from the cabinet, chassis, and associated wiring. The specification is the same emission mask under the Radio Service rules extended to the highest frequency specified in 2.1057. Traditionally a “terminated transmitter” is tested without antenna.
For Licensed equipment, the substitution method described in TIA/EIA 603 is the required test procedure.
For Part 15 emissions testing, direct measurement of field strength is accepted. Device must be tested with it’s antenna in place.