Ultra Compact Chip Antenna
Data Guide
Description
The exciting ANT-***-CHP family is among the world’s
smallest high-performance chip antennas. They are
ideal for embedding in wireless products including
Bluetooth, 802.11, Home RF, ZigBee and other
popular standards. These tiny antennas use advanced
Low Temperature Co-fired Ceramic (LTCC) technology
and proprietary elements to achieve superior size and
performance characteristics. The entire family is com-
patible with hand and reflow-assembly.
Excellent electrical specifications, stability,
and outstanding cost-effectiveness make
2.4
CHP Series antennas the logical choice
for a wide variety of applications.
2.4
Figure 1: 2.4GHz Dimensions
xxx
Features
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Incredibly compact SMD package
Superior LTCC technology
50Ω characteristic impedance
Low loss
Wide bandwidth
Favorable linear polarization
> Unity gain
No external matching required
Highly stable over temperature & time
Hand and reflow-assembly compatible
RoHS compliant
Cost-effective
Figure 2: 868MHz and 916MHz Dimensions
2.45GHz
868MHz
916MHz
Figure 3: Actual Sizes
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Revised 8/8/12
Applications
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Bluetooth
802.11
ZigBee
Wireless PCMCIA cards
Telemetry
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Data collection
Industrial process monitoring
Compact wireless products
External antenna elimination
Footprints
0.260"
0.630"
0.100"
0.130"
Ordering Information
Ordering Information
Part Number
ANT-868-CHP-x
ANT-916-CHP-x
ANT-2.45-CHP-x
Description
868Mhz Chip Antenna
916MHz Chip Antenna
2.45GHz Chip Antenna
0.040"
Figure 6: 2.4GHz Footprint
0.040"
Figure 7: 868MHz and 916MHz Footprint
Pin Configuration
x = "T" for tape/reel, "B" for bulk
All parts are RoHS compliant.
Standard reel is 3,000pcs. (868/916MHz), 1,500pcs. (2.45GHz)
Quantities less than reel size are supplied in bulk.
Figure 4: Ordering Information
1
Figure 8: Pin Configuration
Pin Descriptions
Pin Number
2.4
2
Description
Feed Termination
This pin connects to the transmitter or receiver.
Solder Termination
This pin is soldered down for physical support only. There is no
electrical connection.
Electrical Specifications
Specifications
Parameter
Physical
Dimensions (mm)
Operating/Storage Temp
Construction
Electrical
Center Frequency
Bandwidth
Wavelength
Pattern
Polarization
VSWR
Maximum Gain
Impedance
Power Handling
Figure 5: Ordering Information
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2
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2.45GHz
180MHz
¼-wave
Omni-directional
Linear
≤2.0
(Max.)
+0.5dBi
50Ω
3W (Max.)
868MHz
10MHz
¼-wave
Omni-direction
Linear
≤2.0
(Max.)
+0.5dBi
50Ω
3W (Max.)
916MHz
10MHz
¼-wave
Omni-directional
Linear
≤2.0
(Max.)
+0.5dBi
50Ω
3W (Max.)
6.5(L) x 2.2(W) x
1.0(H)
–40 to +85°C
LTCC
16.0(L) x 3.0(W) x
1.7(H)
–40 to +85°C
LTCC
16.0(L) x 3.0(W) x
1.7(H)
–40 to +85°C
LTCC
2.45GHz
868MHz
916MHz
1
2
Figure 9: Pin Configurations
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Theory of Operation
The CHP Series antennas utilize Low Temperature Cofired Ceramic (LTCC)
technology to embed the antenna element into a ceramic substrate.
Advances in this technology have resulted in materials that are extremely
stable over time and temperature, producing an antenna that is highly
reliable across a wide range of applications. The high-frequency charac-
teristics of this technology enable exceptional performance in a very small
package. The construction techniques for LTCC devices lends itself well to
favorable pricing in high volume.
Microstrip Details
A transmission line is a medium whereby RF energy is transferred from
one place to another with minimal loss. This is a critical factor, especially in
high-frequency products like Linx RF modules, because the trace lead-
ing to the module’s antenna can effectively contribute to the length of
the antenna, changing its resonant bandwidth. In order to minimize loss
and detuning, some form of transmission line between the antenna and
the module should be used unless the antenna can be placed very close
(<1/8in.) to the module. One common form of transmission line is a coax
cable and another is the microstrip. This term refers to a PCB trace run-
ning over a ground plane that is designed to serve as a transmission line
between the module and the antenna. The width is based on the desired
characteristic impedance of the line, the thickness of the PCB and the
dielectric constant of the board material. For standard 0.062in thick FR-4
board material, the trace width would be 111 mils. The correct trace width
can be calculated for other widths and materials using the information in
Figure 11 and examples are provided in Figure 12. Software for calculating
microstrip lines is also available on the Linx website.
Trace
Board
Ground plane
Layout Considerations
Proper layout is vital to ensure correct operation and optimum perfor-
mance. Improper placement of planes, traces, or system components will
result in nulls or complete de-tuning. Ideally, the antenna will be mounted
on the board in such a way as to allow an unobstructed field of view.
The area underneath the antenna must be free of components, traces,
and planes. Components may be placed to the rear of the antenna in the
ground plane counterpoise area. The feed trace from the RF stage to the
antenna must be a microstrip trace or coax transmission line and should be
kept as short as practical.
The layout of our reference jigs is illustrated on the following pages.
While they demonstrate various aspects of a layout, it is not necessary
to replicate them exactly. While your board size and layout may differ, it
is important to recognize that the counterpoise plays an important role in
resonance and stability since it acts, in essence, as part of the antenna.
After your own layout is complete, the performance of the antenna in your
specific product should be carefully checked using tools like a network
analyzer. In some cases, the size of the product’s PCB, proximity of the
case, or other factors may make a custom version of the antenna
necessary. Contact Linx for more information.
No electrical connection.
For physical support only
No ground plane or traces
under the antenna
PCB pads for the CHP
Ground plane on bottom
layer for counterpoise
50-ohm microstrip line
2.4
Figure 11: Microstrip Formulas
Example Microstrip Calculations
Dielectric Constant
4.80
4.00
2.55
Width / Height
Ratio (W / d)
1.8
2.0
3.0
Effective Dielectric
Constant
3.59
3.07
2.12
Characteristic
Impedance (Ω)
50.0
51.0
48.8
Figure 10: Layout
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Figure 12: Example Microstrip Calculations
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