Technical Specs
Table Of Contents
- Important Notice
- Safety and Hazards
- Limitation of Liability
- Patents
- Copyright
- Trademarks
- Contact Information
- Revision History
- 1: Introduction
- 2: Electrical Specifications
- 3: RF Specifications
- 4: Power
- 5: Software Interface
- 6: Mechanical and Environmental Specifications
- 7: Regulatory Compliance and Industry Certifications
- A: Antenna Specification
- B: Design Checklist
- C: Packaging
- D: References
- E: Acronyms
- Index
RF Specifications
Rev 3 Oct.20 37 41113694
The severity of this interference depends on the closeness of the other antennas to the
module’s antenna. To determine suitable locations for each wireless device’s antenna,
thoroughly evaluate your host device’s design.
Host-generated RF Interference
All electronic computing devices generate RF interference that can negatively affect the
receive sensitivity of the module.
Proximity of host electronics to the antenna in wireless devices can contribute to
decreased Rx performance. Components that are most likely to cause this include:
• Microprocessor and memory
• Display panel and display drivers
• Switching-mode power supplies
Device-generated RF Interference
The module can cause interference with other devices. Wireless devices such as AirPrime
embedded modules transmit in bursts (pulse transients) for set durations (RF burst
frequencies). Hearing aids and speakers convert these burst frequencies into audible
frequencies, resulting in audible noise.
Methods to Mitigate Decreased Rx Performance
It is important to investigate sources of localized interference early in the design cycle. To
reduce the effect of device-generated RF on Rx performance:
• Put the antenna as far as possible from sources of interference. The drawback is that
the module may be less convenient to use.
• Shield the host device. The module itself is well shielded to avoid external inter-
ference. However, the antenna cannot be shielded for obvious reasons. In most
instances, it is necessary to employ shielding on the components of the host device
(such as the main processor and parallel bus) that have the highest RF emissions.
• Filter out unwanted high-order harmonic energy by using discrete filtering on low
frequency lines.
• Form shielding layers around high-speed clock traces by using multi-layer PCBs.
• Route antenna cables away from noise sources.
Radiated Spurious Emissions (RSE)
When designing an antenna for use with AirPrime embedded modules, the host device
with an AirPrime embedded module must satisfy any applicable standards/local
regulatory bodies for radiated spurious emission (RSE) for receive-only mode and for
transmit mode (transmitter is operating).
Note that antenna impedance affects radiated emissions, which must be compared
against the conducted 50 emissions baseline. (AirPrime embedded modules meet the
50 conducted emissions requirement.)