DeFelsko BLEATA BLEATA Module User Manual Antenna Design Guide
DeFelsko Corporation BLEATA Module Antenna Design Guide
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Contents
- 1. Antenna Design Guide
- 2. Users Manual
Antenna Design Guide
ANTENNA DESIGN
G
UIDE
Last updated
June 16th, 2015
1 Introduction
1.1 Purpose & Scope
The purpose of this document is to provide details regarding the design and integration
of the certified chip antenna for the module. It will inform the designer as to the required
PCB layout details, and provide expected performance specifications.
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2 Chip Antenna
The Johanson Technology ceramic chip antenna is a passive, surface mount
component, based on Low Temperature Co-fired Ceramic (LTCC) technology. This
antenna exhibits linear polarization and provides a near omni-directional radiation
pattern. It is matched to 50 ohm impedance and is well suited for integration to the radio
module.
The chip antenna is used external to the module, as part of an overall solution.
Johanson Part Number Description
2450AT43B100
2.4 GHz Ceramic Chip Antenna
Table 2 Chip Antenna
Overview
2.1 Chip Antenna Specifications
Specification
V
alue
Peak Gain +1.3 dBi
Impedance 50 ohms, Nominal
Type Chip
Polarization Linear
Frequency 2400-2500 MHz
Input Power 2W max
Size 7 mm × 2 mm
Operating Temperature -40 to +85°C
Table 3 Chip Antenna Specifications
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2.2 Mechanical Dimensions
Table 4 Chip Antenna Mechanical Dimensions
2.3 Terminal Configuration
Table 5 Chip Antenna Terminal Configuration
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2.4 Typical Radiation
Patterns
Figure
1
Chip
Antenna
Radiation
Patterns
3 PCB Layout Requirements
Since the module and its associated approved antenna have been certified by the FCC
and Industry Canada (IC) as a Modular Radio, the end user is authorized to integrate
this module into an end-product, and is solely responsible for the Unintentional
Emissions levels produced by the end-product.
In order to preserve the Modular Radio certification, the integrator of the module must
abide by the PCB layout recommendations outlined in the following paragraphs. Any
divergence from these recommendations will invalidate the modular radio certifications
and require the integrator to re-certify the modules and/or end-product.
The modules must be used with one of the approved antennas:
1. Johnson 2450AT43B100 2.4 GHz ceramic chip antenna.
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3.1 Chip Antenna PCB Layout Requirements
Figure 2 Chip Antenna PCB Layout Requirements
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3.2 Chip Antenna Reference Design PCB
Figure 3 Chip Antenna Certified Reference Design PCB
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3.3 Chip Antenna Reference Design Schematic
Figure 4 Chip Antenna Certified Reference Design Schematic
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3.4 Chip Antenna Matching Inductors
Two inductors are required to properly match the chip antenna. Refer to the table below
for specifics on the inductors. Additional it is required to populate a zero ohm resistor R7
between the module and the matching inductors.
Figure 5 Chip Antenna PCB Layout Requirements
Inductor
Value
Part Number Description
L4
2.7nH Johanson L-07C2N7SV6T Inductor in series with the antenna
L5
2.2nH Johanson L-07C2N2SV6T Inductor to ground in antenna path
Table 6 Chip Antenna Matching Inductors
4 EMC Compliance
4.1 Summary
The module has been tested and approved as a Modular Radio in accordance with the
appropriate FCC and IC standards. The supporting test data may be found in the
modular test report.
Since the module and its associated approved antenna has been certified as a Modular
Radio, this allows the end user to integrate these modules into an end-product without
the requirement of re-certifying the radio module. The module-integrator is responsible
for the unintentional conducted and radiated emissions and must verify that the
integrated product is compliant with the rules associated with unintentional radiators.
The module integrator is also required to maintain an engineering record of the
verification testing and declare on the product through proper labeling and marking that
the device is compliant with these particular rules.
The installed module’s FCC ID and IC numbers need to be clearly marked on the
product with the following verbiage “contains FCC ID: OEJ-MAPWIFI, 15.247”
and "contains IC: 297A-MAPWIFI, RSS 210".
The module has been certified for use in a mobile configuration, which employs a
minimum separation distance of 20 cm from the antenna to the human body or another
transmitting radio. For separation distances of 20 cm or less, the module integrator must
have the module certification re-evaluated, which will include a modification to the
existing certification and additional testing for exposure and SAR requirements.
4.2 Module Integration Considerations – Antenna Systems
The modules must be used with one of the approved antennas:
1. Johnson 2450AT43B100 2.4 GHz ceramic chip antenna.
The antenna should be placed such that it is minimally disturbed by the product’s
packaging material. The incorporation of the largest practical free-space clearance
around the antenna is important for maximizing overall performance. Further, the
antenna must be placed such that at least a 20 cm separation distance is maintained
from the human body to the antenna and all other radio transmitters.
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4.3 Module Integration Considerations – Substitute Antenna
Systems
The modules’ certification is only valid for the list of approved antennas presented in
section 4.2. However, substitute antennas may be used in place of the approved
antenna only if the antennas are of the same type and the peak gain is less than or
equal to the peak gain of the similar approved antenna. Also the antennas should
have similar in-band and out-of-band characteristics.
4.4 Module Integration Considerations – Circuit Implementation
It is recommended that all connection PCB (printed circuit board) traces to the power
supply and digital control terminal be as short as possible. Though not necessarily
required in all cases, it is a best practice to provide an optional shunt capacitor
placement at the module pin on all active and routed power supply and digital control
lines. Further, a series damping resistor placement should be incorporated between
the module pin/shunt capacitor node and the source/sink of the digital control signals.
This provides for effective bypassing and decoupling of digital lines from the radio
module, in the event that the application circuit has longer power supply and digital
routing.
4.5 Module Integration Considerations - Top Assembly
In addition to the recommendations given for the antenna systems and the module
placement onto a product PCB, it is recommended that all wiring and interconnect
systems within the product be not routed anywhere close the module and its
associated circuitry on the PCB, doing so could change the emission characteristics
of the module.
4.6 Testing Requirements for End-Product
Once the module is integrated and the product realized in a mobile configuration, the
product must be tested and follow the verification process for Unintentional
Conducted and Radiated Emissions in accordance to the FCC and IC guidelines.
The module needs to be powered and placed in the receive mode for this test. The
receiver must be tuned to its lowest frequency channel, mid-frequency channel, and
highest frequency channel. The supporting test data does not need to be submitted
to the FCC or IC.
4.7 SAR Testing Requirements for End-Product
Since the radio modules were certified in a mobile configuration, the end- product
does not require SAR testing if the end-product is not used within 20cm of the
human body, nor used in conjunction with another radio transmitter.
For portable configurations (antenna-to-body separations of less than 20 cm), the
module integrator must have the module’s certification re-evaluated, which will
include a modification to the existing certification and additional testing for exposure
and SAR requirements.